INTRODUCTION  介紹 — 

Intestinal ischemia is caused by a reduction in blood flow to a level that is insufficient for the delivery of oxygen and nutrients required for cellular metabolism [1]. It can be related to acute arterial occlusion (embolic, thrombotic), venous thrombosis, or hypoperfusion of the mesenteric vasculature causing nonocclusive ischemia. The incidence is estimated at 16 cases per 100,000 person-years, which has increased over time [2].
腸缺血是由於血流量減少到不足以輸送細胞代謝所需的氧氣和營養物質的水準所致[1]。它可能與急性動脈閉塞（栓塞性、血栓性）、靜脈血栓形成或腸系膜脈管系統灌注不足導致非閉塞性缺血有關。發病率估計為 16 例/100,000 人年，並且隨著時間的推移而增加[2]。

Colonic ischemia is the most frequent form of intestinal ischemia, most often affecting older adults [3]. Colonic ischemia may be more prevalent in females. Colonic ischemia should be suspected in patients with lower abdominal pain and bloody diarrhea or hematochezia; however, these symptoms are nonspecific.
結腸缺血是最常見的腸缺血形式，最常累及老年人[3]。結腸缺血在女性中可能更為普遍。下腹痛、血性腹瀉或便血患者應懷疑結腸缺血;然而，這些癥狀是非特異性的。

Approximately 15 percent of patients with colonic ischemia develop necrotic bowel, the consequences of which can be life-threatening, making rapid diagnosis and treatment imperative. Most cases of colonic ischemia are usually transient and resolve without sequelae [4]. However, some patients will have a more prolonged course or develop long-term complications, such as stricture or chronic ischemic colitis.
大約 15% 的結腸缺血患者會出現壞死性腸，其後果可能危及生命，因此必須快速診斷和治療。大多數結腸缺血病例通常是一過性的，消退後無後遺症[4]。然而，有些患者的病程會更長或出現長期併發症，如狹窄或慢性缺血性結腸炎。

The diagnosis and treatment of colonic ischemia can be challenging since it often occurs in patients who are debilitated and have multiple medical problems. The clinical features, diagnosis, and treatment of ischemia affecting the colon, including acute colonic ischemia and chronic ischemic colitis (which sometimes affects the rectum), will be reviewed here. Acute and chronic intestinal ischemia of the small intestine are discussed separately. (See "Overview of intestinal ischemia in adults" and "Chronic mesenteric ischemia".)
結腸缺血的診斷和治療可能具有挑戰性，因為它通常發生在虛弱且有多種醫療問題的患者身上。本文將總結累及結腸的缺血，包括急性結腸缺血和慢性缺血性結腸炎（有時累及直腸）的臨床特徵、診斷和治療。小腸急性和慢性腸缺血詳見其他專題。（參見 “成人腸缺血概述” 和 “慢性腸系膜缺血”）

COLON ANATOMY AND PATHOPHYSIOLOGY
結腸解剖學和病理生理學 — 

Colonic ischemia is usually the result of a sudden, but usually transient, reduction in blood flow, the effects of which are particularly prominent at the "watershed" regions of the colon, where collateral blood flow is limited.
結腸缺血通常是血流量突然減少的結果，其影響在結腸的“分水嶺”區域尤為突出，那裡的側支血流受到限制。

Blood supply of the colon — The circulation to the large intestine and rectum is derived from the superior mesenteric artery (SMA), inferior mesenteric artery (IMA), and internal iliac arteries (figure 1). The colorectal circulation is relatively constant, excepting relatively rare anatomic variations [5,6]. The mesenteric veins parallel the arterial circulation, draining into the portal venous system (figure 2). An extensive collateral circulation (figure 3) protects the intestines from transient periods of inadequate perfusion [7,8]. However, the "watershed" areas of the colon, which have limited collateral blood flow, such as the splenic flexure and rectosigmoid junction, are at risk for ischemia, particularly related to hypoperfusion [9-11].
結腸  血液供應 —  大腸和直腸的迴圈來源於腸系膜上動脈（superior mesenteric artery， SMA）、腸系膜下動脈（suberior mesenteric artery， IMA）和髂內動脈 （ 圖 1）。結直腸循環相對恆定，但相對罕見的解剖變異除外[5,6]。腸系膜靜脈與動脈迴圈平行，流入門靜脈系統 （ 圖 2）。廣泛的側支迴圈 （ 圖 3） 可保護腸道免受短暫灌注不足的影響[7,8]。然而，結腸的「分水嶺」區域，如脾屈和直腸乙狀結腸交界處，側支血流有限，有缺血的風險，尤其是與灌注不足有關[9-11]。

Etiology of hypoperfusion — The colon is relatively vulnerable to hypoperfusion since it receives less blood flow compared with the rest of the gastrointestinal tract. In addition, the microvascular plexus of the colon is less developed and is embedded in a relatively thick wall compared with the small bowel. Prolonged severe ischemia causes necrosis of the villous layer, which can lead to transmural infarction within 8 to 16 hours [12].
低灌注  的病因 —  結腸相對容易發生低灌注，因為與胃腸道其他部位相比，結腸的血流量較少。此外，與小腸相比，結腸微血管叢不太發達，嵌入相對較厚的壁中。長期嚴重缺血可導致絨毛層壞死，可在 8-16 小時內導致透壁梗死[12]。

Perfusion to the colon can be compromised by changes in the systemic circulation or by anatomic or functional changes in the local mesenteric vasculature. Three main mechanisms are responsible for intestinal ischemia.
結腸灌注可能因體循環的變化或局部腸系膜脈管系統的解剖或功能變化而受到影響。導致腸缺血的三個主要機制。

●Nonocclusive colonic ischemia – Nonocclusive or low blood flow ischemia is the predominant mechanism (95 percent of cases) causing colonic ischemia [1]. Nonocclusive colonic ischemia is typically transient, although prolonged nonocclusive ischemia can lead to transmural necrosis [12]. Nonocclusive colonic ischemia most commonly affects the "watershed" areas of the colon that have limited collateralization, such as the splenic flexure and rectosigmoid junction [6,10]. In a study of more than 1000 patients, the left colon was involved in approximately 75 percent of patients, with approximately one-quarter of lesions affecting the splenic flexure [11]. The rectum was involved in only 5 percent of patients, which can be explained by collateralization of the inferior mesenteric artery with the systemic circulation through the hemorrhoidal vessels. Low-flow states can also reduce perfusion, causing ischemia of the distal ileum and right colon related to their greater distance from the aorta. (See "Nonocclusive mesenteric ischemia".)
非閉塞性結腸缺血 –非閉塞性或低血流量缺血是導致結腸缺血的主要機制（95%的病例）[1]。非閉塞性結腸缺血通常是一過性的，但長期非閉塞性缺血可導致透壁壞死[12]。非閉塞性結腸缺血最常累及結腸側支有限的“分水嶺”區域，如脾屈和直腸乙狀結腸交界處[6,10]。一項納入 1000 多名患者的研究顯示，約 75%的患者累及左結腸，約 1/4 的病變影響脾屈[11]。只有 5% 的患者受累於直腸，這可以通過腸系膜下動脈的側支與通過痔血管的體循環來解釋。低流量狀態也會減少灌注，導致迴腸遠端和右結腸缺血，這與它們與主動脈的距離較遠有關。（參見 “非閉塞性腸系膜缺血”）

●Embolic and thrombotic arterial occlusion – Colonic ischemia can be due to spontaneous emboli from a proximal source to the mesenteric vessels, or emboli can result iatrogenically from aortic instrumentation. These patients rarely have colonic ischemia without concomitant small bowel ischemia. A case-control study involving 60 patients with segmental colonic ischemia suggested that a potential cardiac source of embolism was present in up to one-third of patients [13]. In patients with mesenteric atherosclerotic occlusive disease, colonic ischemia can occur with progressive superior mesenteric artery stenosis in the setting of an occluded inferior mesenteric artery due to insufficient collateral flow (figure 3). Colonic ischemia can also be related to inferior mesenteric artery ligation during open surgical repair of the aorta. (See "Acute mesenteric arterial occlusion".)
栓塞和血栓性動脈閉塞 – 結腸缺血可能是由於腸系膜血管近端來源的自發性栓子，或者栓子可能是由主動脈器械醫源性引起的。這些患者很少有結腸缺血而沒有伴隨的小腸缺血。一項納入 60 例節段性結腸缺血患者的病例對照研究表明，多達 1/3 的患者存在潛在的心臟栓塞源[13]。腸系膜動脈粥樣硬化性閉塞性疾病患者，在腸系膜下動脈閉塞的情況下，由於側支血流不足，可發生結腸缺血，伴有進行性腸系膜上動脈狹窄 （ 圖 3）。結腸缺血也可能與主動脈開放手術修復期間的腸系膜下動脈結紮有關。（參見 “急性腸系膜動脈閉塞”）

●Mesenteric vein thrombosis – Mesenteric vein thrombosis rarely affects the colon; when present, it almost always affects the distal small intestine/proximal colon [14]. Phlebosclerotic colitis is a rare form of ischemic colitis that results from venous obstruction caused by fibrotic sclerosis and calcification of the walls of the mesenteric veins [15]. (See "Mesenteric venous thrombosis in adults".)
腸系膜靜脈血栓形成 – 腸系膜靜脈血栓形成很少影響結腸;當存在時，幾乎總是累及遠端小腸/近端結腸[14]。靜脈硬化性結腸炎是一種罕見的缺血性結腸炎，由纖維化硬化和腸系膜靜脈壁鈣化引起的靜脈阻塞引起[15]。（參見 “成人腸系膜靜脈血栓形成”）

The injury to the colon following an ischemic event is due to hypoxia and the sequelae of reperfusion. The hypoxic component causes detectable injury in the superficial part of the mucosa within one hour. With prolonged ischemia, irreversible damage with full-thickness ischemia leading to transmural necrosis can occur and require bowel resection. The reperfusion component of intestinal injury is mainly seen following partial ischemia with reperfusion. It is initiated by an increased release of oxygen free radicals, other toxic byproducts of ischemic injury, and neutrophil activation [16]. Reperfusion injury can lead to multisystem organ failure.
缺血事件後結腸損傷是由於缺氧和再灌注的後遺症造成的。缺氧成分在一小時內導致粘膜淺表部分可檢測到的損傷。隨著長期缺血，可能會發生不可逆的損傷，並伴有全層缺血，導致透壁壞死，需要腸切除術。腸損傷的再灌注成分主要見於部分缺血再灌注后。它是由氧自由基、缺血性損傷的其他有毒副產物和中性粒細胞活化釋放增加引起的[16]。再灌注損傷可導致多系統器官衰竭。

Uncertain role of hypercoagulability — The degree to which acquired or hereditary hypercoagulable states contribute to the pathogenesis of colonic ischemia is uncertain [17-21]. The observed prevalences of thrombophilic abnormalities in these studies must be reconciled with the generally later presentation (mean age 65) of colonic ischemia and that recurrence of colonic ischemia is uncommon [17]. This suggests that other factors must be involved in precipitating an ischemic event (a "two-hit" hypothesis). It is also possible that specific types of thrombophilic disorders may predispose to particular forms of colonic ischemia, such as chronic ischemic colitis and stricture formation.
高凝狀態  的作用不確定 —  獲得性或遺傳性高凝狀態在多大程度上促成結腸缺血的發病機制尚不確定[17-21]。這些研究中觀察到的血栓形成異常的患病率必須與結腸缺血的一般較晚表現（平均年齡 65 歲）相一致，結腸缺血的復發並不常見[17]。這表明必須涉及其他因素來誘發缺血事件（“兩次命中”假設）。特定類型的血栓形成性疾病也可能易患特定形式的結腸缺血，例如慢性缺血性結腸炎和狹窄形成。

However, one report from Greece compared the prevalence of a variety of hypercoagulable states among 36 patients with colonic ischemia, 18 patients with diverticulitis, and 52 healthy controls [21]. The prevalence of antiphospholipid antibodies was significantly higher among patients with colonic ischemia compared with those with diverticulitis or controls (19.4 versus 0 and 1.9 percent, respectively). Factor V Leiden mutations were also found more frequently in patients with colonic ischemia (22.2 versus 0 and 3.8 percent, respectively). One of several prothrombotic abnormalities was present in 26 patients (72 percent). Another study focused on 19 patients with nonocclusive colonic ischemia who were younger than 55 years. Compared with a group of 52 matched healthy controls, patients with colonic ischemia were significantly more likely to have polymorphisms in factor V Leiden and plasminogen activator inhibitor that may predispose to thrombophilia.
然而，希臘的一份報告比較了 36 例結腸缺血患者、18 例憩室炎患者和 52 例健康對照者中多種高凝狀態的患病率[21]。與憩室炎患者或對照組相比，結腸缺血患者的抗磷脂抗體患病率顯著高於憩室炎患者或對照組患者（分別為 19.4% vs 0%和 1.9%）。結腸缺血患者中也更常見於因數 V.萊頓突變（分別為 22.2% vs 0%和 3.8%）。26 例患者（72%）存在幾種血栓形成前異常中的一種。另一項研究重點關注 19 名年齡小於 55 歲的非閉塞性結腸缺血患者。與一組 52 名匹配的健康對照者相比，結腸缺血患者在因數 V 萊頓和纖溶酶原啟動劑抑製劑中出現多態性的可能性明顯更高，這些多態性可能易患血栓形成傾向。

RISK FACTORS  風險因素 — 

Colonic ischemia typically occurs in well-defined clinical settings in patients with risk factors for mesenteric ischemia. However, colonic ischemia can also develop insidiously without identifiable risk factors. Nonpharmacologic and pharmacologic risk factors associated with colonic ischemia are given in the tables (table 1 and table 2). The main risk factors for colonic ischemia are discussed below [22,23]. Older patients are more likely to have these risk factors [1].
結腸缺血通常發生在明確的臨床環境中，發生在有腸系膜缺血危險因素的患者中。然而，結腸缺血也可能在沒有可識別危險因素的情況下隱匿發展。結腸缺血相關的非藥物和藥物危險因素見附表 （ 表 1 和 表 2）。結腸缺血的主要危險因素詳見下文[22,23]。老年患者更容易有這些危險因素[1]。

●Drug effects – Constipation-inducing drugs, immunomodulators, and misused drugs may be best supported as etiologic agents (table 2) [1]. There is also support for a contributing role for many different drug classes, mostly from case reports or small case series [23-29]. The mechanism can be related to the known action or effect of the offending drug. Patients with prior colonic ischemia should probably avoid any implicated drug unless the cause of their ischemia is clearly related to another condition.
藥物作用 –誘發便秘的藥物、免疫調節劑和濫用藥物可能最好作為病原體 （ 表 2）[1]。許多不同類別的藥物也支持發揮作用，主要來自病例報告或小病例系列[23-29]。該機制可能與致病藥物的已知作用或作用有關。既往有結腸缺血的患者可能應避免使用任何相關藥物，除非其缺血的原因明顯與另一種疾病有關。

●Myocardial infarction – Myocardial infarction appears to predispose to colonic ischemia. Colonic ischemia was described in 14 of 100 patients who underwent a colonoscopy within a mean of 15 days after a myocardial infarction [30]. The indications for colonoscopy were overt or occult bleeding in most patients. One report suggested that ischemic colitis developing in the setting of myocardial infarction was associated with more complications and a worse in-hospital prognosis compared with other causes of ischemic colitis [31].
心肌梗死 – 心肌梗塞似乎易患結腸缺血。100 例患者中，有 14 例在心肌梗死後平均 15 日內接受結腸鏡檢查[30]。大多數患者的結腸鏡檢查指征是明顯或隱匿性出血。一項報告提示，與其他缺血性結腸炎病因相比，心肌梗死發生的缺血性結腸炎併發症更多，院內預後更差[31]。

●Hemodialysis – Colonic ischemia in the setting of hemodialysis is typically nonocclusive and is due to underlying diabetes and hemodialysis-induced hypotension [32-35]. (See "Unique aspects of gastrointestinal disease in patients on dialysis".)
血液透析 –血液透析情況下的結腸缺血通常是非閉塞性的，由基礎糖尿病和血液透析誘發的低血壓所致[32-35]。（參見 “透析患者胃腸道疾病的獨特表現”）

●Aortoiliac instrumentation/surgery – Open aortic surgery, such as repair of abdominal aortic aneurysm, particularly ruptured aneurysm; other forms of open aortoiliac reconstruction can lead to colonic ischemia [17,36-39]. With open aortic surgery, subsequent ischemia almost always affects the distal left colon and is related to loss of collateral flow due to inferior mesenteric artery ligation, iliac artery ligation, embolic events, vascular compression with surgical instruments, or hypotension. (See "Procedure-specific and late complications of open aortic surgery in adults", section on 'Intestinal ischemia'.)
主髂器械/手術 – 開放式主動脈手術，例如腹主動脈瘤的修復，特別是破裂的動脈瘤;其他形式的開放性主髂重建可導致結腸缺血[17,36-39]。對於開放式主動脈手術，隨後的缺血幾乎總是影響左結腸遠端，並且與腸系膜下動脈結紮、髂動脈結紮、栓塞事件、手術器械血管壓迫或低血壓導致的側支血流喪失有關。（參見 “成人開放式主動脈手術的特異性併發症和晚期併發症”，關於'腸缺血'一節 ）

Endovascular intervention and other forms of aortic instrumentation (eg, cardiac catheterization, valve implantation) can also be complicated with colonic ischemia [40-42]. (See "Complications of endovascular abdominal aortic repair", section on 'Intestinal ischemia' and "Complications of diagnostic cardiac catheterization", section on 'Atheroembolism' and "Access-related complications of percutaneous access for diagnostic or interventional procedures", section on 'Atheroembolism'.)
血管內介入治療和其他形式的主動脈器械（如心導管插入術、瓣膜植入術）也可能併發結腸缺血[40-42]。（參見 “血管內腹主動脈修復術的併發症”，關於'腸缺血'一節和 “診斷性心導管插入術的併發症”，關於'動脈粥樣硬化栓塞'一節和 “診斷或介入手術經皮通路的通路相關併發症”，關於'動脈粥樣硬化栓塞'一節 ）

●Cardiopulmonary bypass – Colonic ischemia after cardiopulmonary bypass occurs in less than 0.2 percent of patients but is a lethal complication with a mortality rate of up to 85 percent [43,44]. Risk factors include older age, end-stage kidney disease, valve surgery, emergency bypass surgery, and low postoperative cardiac output [45,46]. In addition to the low flow state of bypass perfusion, the procedure exposes the patient's blood to foreign surfaces, which may lead to hypercoagulability, microemboli, alterations in cells and proteins, release of vasoactive substances, and activation of the complement cascade [47]. Long bypass times, use of inotropic agents, and an intra-aortic balloon pump are associated with increased severity of colonic ischemia [48]. Patients with acquired or hereditary thrombophilia may be particularly vulnerable in this setting.
體外迴圈 –體外迴圈後結腸缺血的發生率不到 0.2%，但是一種致死性併發症，死亡率高達 85%[43,44]。危險因素包括高齡、終末期腎病、瓣膜手術、緊急搭橋手術和術后心輸出量低[45,46]。除了旁路灌注的低流量狀態外，該手術還使患者的血液暴露於異物表面，這可能導致高凝、微栓子、細胞和蛋白質改變、血管活性物質釋放以及補體級聯反應啟動[47]。搭橋時間長、使用正性肌力藥物和主動脈內球囊泵與結腸缺血的嚴重程度增加有關[48]。在這種情況下，獲得性或遺傳性血栓形成傾向患者可能特別容易受到影響。

●Extreme exercise – Extreme exercise (eg, marathon running, triathlon competition) has been associated with intestinal ischemia. The ischemia is probably triggered by the shunting of blood flow away from the splanchnic circulation accompanied by dehydration, hyperthermia, and electrolyte abnormalities, including hyponatremia and hypokalemia.
極限運動 –極限運動（如馬拉松跑、鐵人三項比賽）與腸缺血有關。缺血可能是由血流從內臟迴圈分流而引發的，並伴有脫水、體溫過高和電解質異常，包括低鈉血症和低鉀血症。

●Mesenteric arteriovenous fistula or malformation – This rare etiology leads to venous hypertension in the colonic wall that can lead to chronic ischemic colitis [49].
腸系膜動靜脈瘺或畸形 –這種罕見的病因可導致結腸壁靜脈高壓，從而導致慢性缺血性結腸炎[49]。

●Acquired or hereditary thrombophilia – The reported prevalence of thrombophilic abnormalities (eg, antiphospholipid syndrome, factor V Leiden, Protein C deficiency) is increased in some studies [17-21,50]. (See 'Uncertain role of hypercoagulability' above.)
獲得性或遺傳性血栓形成傾向 – 一些研究報導的血栓形成異常（如抗磷脂綜合征、V 因數萊頓、蛋白 C 缺乏症）的患病率有所增加[17-21,50]。（參見上文 '高凝狀態的不確定作用'）

●Following colonoscopy – Ischemic colitis has rarely been associated with diagnostic colonoscopy, possibly related to barotrauma from insufflation, sedating medications, or dehydration associated with bowel preparation [51]. (See "Overview of colonoscopy in adults", section on 'Adverse events'.)
結腸鏡檢查后 –缺血性結腸炎很少與診斷性結腸鏡檢查相關，可能與吹氣、鎮靜藥物或腸道準備相關的脫水引起的氣壓傷有關[51]。（參見 “成人結腸鏡檢查概述”，關於'不良事件'一節 ）

●Severe COVID-19 infection – Colonic and small-bowel ischemia have been reported in patients with severe coronavirus disease 2019 (COVID-19) infection, usually related to thrombophlebitis and hypoperfusion [52]. (See "COVID-19: Gastrointestinal symptoms and complications", section on 'Mesenteric ischemia'.)
重症 COVID-19 感染–COVID-19 重症感染患者有結腸缺血和小腸缺血的報導，通常與血栓性靜脈炎和低灌注有關[52]。（參見 “COVID-19 的胃腸道癥狀和併發症”，關於'腸系膜缺血'一節 ）

CLINICAL FEATURES  臨床特徵 — 

The clinical manifestations of colonic ischemia vary depending upon the clinical setting and onset, duration, and extent of the ischemia. It is important to carefully assess the patient for risk factors associated with colonic ischemia by careful review of the medical and surgical history, including medications and other drug use in each patient. (See 'Risk factors' above and 'Colon anatomy and pathophysiology' above.)
結腸缺血的臨床表現因缺血的臨床環境和發作、持續時間和範圍而異。通過仔細審查每位患者的病史和手術史，包括藥物和其他藥物使用，仔細評估患者與結腸缺血相關的危險因素非常重要。（參見上文 '危險因素' 和 '結腸解剖學和病理生理學'）

Colonic ischemia can present acutely or chronically. Acute manifestations can range from mild to severe and may include colonic edema or bleeding, diarrhea, and ischemic ulceration that can be severe enough to cause stricture, pancolitis, colonic gangrene, or sepsis [17,53]. It may be difficult to identify symptoms in patients who are unconscious, such as those in an intensive care unit, or who are cognitively impaired, such as those with delirium or dementia [54]. A systematic review suggested that a lack of rectal bleeding, peritonitis, or kidney dysfunction were predictors of low severity, whereas right-sided colitis was the most significant predictor of severe disease [55]. Right-sided colonic ischemia is associated with mesenteric ischemia and increased mortality. (See 'Mortality' below.)
結腸缺血可以急性或慢性出現。急性表現從輕度到重度不等，可能包括結腸水腫或出血、腹瀉和缺血性潰瘍，嚴重程度可引起狹窄、全結腸炎、結腸壞瘼或膿毒癥[17,53]。對於意識不清的患者（如重症監護病房患者）或認知障礙患者（如譎妄或失智患者）的癥狀，可能難以識別[54]。一項系統評價提示，無直腸出血、腹膜炎或腎功能不全是低嚴重程度的預測因素，而右側結腸炎是重症疾病的最重要預測因素[55]。右側結腸缺血與腸系膜缺血和死亡率增加有關。（參見下文 '死亡率'）

Acute colonic ischemia  急性結腸缺血

Symptoms and signs — Patients with acute colonic ischemia usually present with rapid onset of mild cramping abdominal pain and tenderness over the affected bowel, most often involving the left side (figure 4) [56]. The pain can be associated with an urgent desire to defecate [6,56]. Compared with ischemia affecting the small intestine, the cramping pain that accompanies colonic ischemia is usually felt laterally rather than periumbilically and is often associated with hematochezia. (See "Overview of intestinal ischemia in adults", section on 'Clinical features' and 'Large versus small bowel ischemia' below.)
癥狀和體征  —  急性結腸缺血患者通常表現為快速發作輕度痙攣性腹痛和累腸壓痛，最常見於左側 （ 圖 4）[56]。疼痛可能與排便的迫切慾望有關[6,56]。與影響小腸的缺血相比，伴隨結腸缺血的痙攣性疼痛通常在側向而不是臍周圍感覺，並且通常與便血有關。（參見 “成人腸缺血概述”，關於'臨床特徵'一節和 '大腸缺血與小腸缺血 '）

Mild-to-moderate amounts of rectal bleeding (bright or maroon blood) or bloody diarrhea usually develop within 24 hours of the onset of abdominal pain, though bleeding without prior abdominal pain also occurs frequently. Bleeding may be more common with ischemia of the left compared with the right colon (83.8 versus 36.4 percent in one study [57]). Approximately 15 percent of patients have abdominal pain without evidence of bleeding.
輕度至中度直腸出血（鮮血或栗色血）或血性腹瀉通常在腹痛發作后 24 小時內出現，但也經常發生無腹痛的出血。與右結腸缺血相比，左結腸缺血的出血可能更常見（1 項研究為 83.8% vs 36.4%[57]）。大約 15% 的患者有腹痛，但沒有出血證據。

Three progressive clinical stages have been described [58,59]:
研究描述了 3 個進行性臨床分期[58,59]：

●Hyperactive phase – Soon after occlusion or hypoperfusion, severe pain dominates with frequent passage of bloody, loose stools. Blood loss is usually mild without the need for transfusion.
過度活躍期 – 閉塞或灌注不足后不久，劇烈疼痛佔主導地位，並經常排出血性稀便。失血量通常是輕微的，不需要輸血。

●Paralytic phase – The pain usually diminishes, becomes more continuous, and diffuses. The abdomen becomes more tender and distended without bowel sounds.
麻痹期 – 疼痛通常會減輕、變得更加持續並瀰漫。腹部變得更加柔軟和膨脹，沒有腸鳴音。

●Shock phase – Massive fluid, protein, and electrolytes start to leak through a damaged, gangrenous mucosa. Severe dehydration with shock and metabolic acidosis may develop, requiring rapid surgical intervention. Fortunately, this most severe form affects only 10 to 20 percent of patients.
休克期 – 大量液體、蛋白質和電解質開始從受損的壞疽粘膜中滲漏。可能會出現嚴重脫水伴休克和代謝性酸中毒，需要迅速進行手術干預。幸運的是，這種最嚴重的形式只影響 10% 到 20% 的患者。

Following aortoiliac instrumentation or surgery, the passage of bloody stools, unexplained failure of postoperative progress, lactic acidosis, fever, leukocytosis, or thrombocytopenia should raise suspicion for colonic ischemia [60,61].
主髂器械或手術后，血便、不明原因術后進展失敗、乳酸性酸中毒、發熱、白細胞增多或血小板減少應懷疑結腸缺血[60,61]。

Transmural necrosis as a consequence of severe hypoperfusion presents as colon perforation with localized or generalized peritonitis or with sepsis, which is less common. In a review of 364 patients, peritoneal signs were present in only 7.4 percent of patients [57].
嚴重灌注不足導致的透壁壞死表現為結腸穿孔伴局部或全身性腹膜炎或膿毒症，這種情況不太常見。一項納入 364 例患者的綜述顯示，只有 7.4%的患者出現腹膜征[57]。

Laboratory studies — Laboratory studies are routinely obtained during the initial evaluation of the patient with abdominal pain or gastrointestinal bleeding, including complete blood count, metabolic panel, and coagulation studies. Although these are not diagnostic for colonic ischemia, they may aid the assessment of disease severity [62]. (See "Overview of intestinal ischemia in adults", section on 'Laboratory studies'.)
實驗室檢查  —  在對腹痛或消化道出血患者進行初始評估時，常規進行實驗室檢查，包括全血細胞計數、代謝檢查和凝血檢查。雖然這些不能診斷結腸缺血，但可能有助於評估疾病嚴重程度[62]。（參見 “成人腸缺血概述”，關於'實驗室檢查'一節 ）

There are no specific laboratory markers for ischemia, although increased serum lactate, lactate dehydrogenase (LDH), creatine phosphokinase (CPK), or amylase may indicate advanced tissue damage. Decreased hemoglobin levels may reflect intestinal blood loss. White blood count above 20,000 cells/microliter and metabolic acidosis in a patient with signs and symptoms of colonic ischemia is highly suggestive of intestinal ischemia with infarction. In a multicenter review, albumin levels below 2.8 g/dL were present on admission in 23.2 percent and were more common in those with gangrenous changes [57].
缺血沒有特異性的實驗室標誌物，但血清乳酸、乳酸脫氫酶 （LDH）、肌酸磷酸激酶 （CPK） 或澱粉酶升高可能提示晚期組織損傷。血紅蛋白水準降低可能反映腸道失血。白細胞計數高於 20,000 個細胞/微升，在有結腸缺血體征和癥狀的患者中出現代謝性酸中毒，高度提示腸缺血伴梗死。一項多中心評價顯示，23.2%的白蛋白水平低於 2.8g/dL，多見於壞疽改變患者[57]。

Fecal polymerase chain reaction testing for pathogens should be ordered to rule out an infectious etiology of bloody diarrhea. Clostridioides difficile infection uncommonly presents with bloody diarrhea, but occasionally, C. difficile superinfection may be superimposed on colonic ischemia. (See "Clostridioides difficile infection in adults: Clinical manifestations and diagnosis".)
應進行糞便聚合酶鏈反應檢測以排除血性腹瀉的感染性病因。 艱難梭菌感染罕見於血性腹瀉，但偶爾， 艱難梭菌重複感染可能疊加結腸缺血。（參見 “成人艱難梭菌感染的臨床表現和診斷”）

Chronic ischemic colitis — Patients with episodes of chronic recurrent colonic ischemia can present with recurrent abdominal pain, bloody diarrhea, weight loss from protein-losing enteropathy, recurrent bacteremia, persistent sepsis, or symptomatic colonic strictures [63]. Approximately 20 percent of patients with recurrent ischemia develop chronic ischemic colitis [63].
慢性缺血性結腸炎  —  慢性復發性結腸缺血發作的患者可表現為反覆腹痛、血性腹瀉、蛋白丟失性腸病導致的體重減輕、復發性菌血症、持續性膿毒症或有癥狀的結腸狹窄[63]。約 20%的復發性缺血患者會發展為慢性缺血性結腸炎[63]。

Chronic ischemia may develop into segmental ulcerating colitis or strictures, typically apparent within three to six months. For lesions that manifest with symptoms, a colonoscopy may be required to confirm persistent colitis or stricture.
慢性缺血可能發展為節段性潰瘍性結腸炎或狹窄，通常在三到六個月內明顯出現。對於有癥狀的病變，可能需要進行結腸鏡檢查以確認持續性結腸炎或狹窄。

Ischemic strictures that produce no symptoms should be observed. Some strictures will resolve in 12 to 24 months without specific therapy. If symptoms of partial obstruction develop, segmental resection is indicated [64]. Endoscopic dilation or stenting, which is primarily used to palliate malignant obstruction, may be an alternative for patients who are poor surgical candidates [65,66]. However, the efficacy of this approach has not been established in this population of patients. (See "Enteral stents for the management of malignant colorectal obstruction".)
應觀察不產生癥狀的缺血性狹窄。一些狹窄將在 12 至 24 個月內消退，無需特殊治療。如果出現部分梗阻癥狀，則需要進行節段切除[64]。內鏡下擴張術或支架置入術主要用於緩解惡性梗阻，對於手術條件不佳的患者，可能是一種替代方法[65,66]。然而，這種方法在該患者群體中的療效尚未確定。（參見 “腸內支架治療惡性結直腸梗阻”）

Chronic ischemic colitis can occur in long-distance runners and presents with pain in the lower abdomen, diarrhea, and mild bleeding. Treatment with rehydration and correction of metabolic abnormalities is usually sufficient [67]. (See "Exercise-related gastrointestinal disorders".)
慢性缺血性結腸炎可發生在長跑運動員身上，表現為下腹部疼痛、腹瀉和輕度出血。補液和糾正代謝異常通常就足夠了[67]。（參見 “運動相關性胃腸道疾病”）

Phlebosclerotic colitis is a rare form of ischemic colitis that results from venous obstruction caused by fibrotic sclerosis and calcification of the walls of the mesenteric veins [15]. It usually involves the right colon. Linear calcifications in the region of the right colon can be seen on plain abdominal radiographs, while computed tomography (CT) scans may reveal colonic wall thickening associated with mesenteric venous calcifications. Symptoms usually resolve spontaneously.
靜脈硬化性結腸炎是一種罕見的缺血性結腸炎，由纖維化硬化和腸系膜靜脈壁鈣化引起的靜脈阻塞引起[15]。它通常涉及右結腸。在腹部 X 光片平片上可以看到右結腸區域的線性鈣化，而計算機斷層掃描 （CT） 掃描可能會顯示與腸系膜靜脈鈣化相關的結腸壁增厚。癥狀通常會自行消退。

DIAGNOSIS  診斷 — 

Suspicion for colonic ischemia should be increased in patients (particularly in older adults) with any of the risk factors discussed above (see 'Risk factors' above) and with lower abdominal pain and bloody diarrhea or hematochezia; however, these symptoms are nonspecific. In a multicenter study from Spain that included 364 patients, the condition was initially suspected in only approximately 25 percent of patients [57]. In another review, the presence of four or more risk factors (ie, older than 60, hemodialysis, hypertension, hypoalbuminemia, diabetes mellitus, constipation-inducing medications) was 100 percent predictive of colonic ischemia [68]. The diagnosis of colonic ischemia is usually suspected based on such history, together with physical examination and clinical setting. It is confirmed with imaging, when possible, typically with CT of the abdomen.
對於有上述任何危險因素（參見上文』危險因素'）且有下腹痛和血性腹瀉或便血的患者（尤其是老年人），應增加對結腸缺血的懷疑;然而，這些癥狀是非特異性的。一項來自西班牙的多中心研究納入了 364 例患者，結果顯示，最初僅約 25%的患者懷疑該病[57]。另一項綜述發現，存在 4 種或 4 種以上危險因素（即 60 歲以上、血液透析、高血壓、低白蛋白血症、糖尿病、便秘誘發藥物）可 100%預測結腸缺血[68]。通常根據此類病史、體格檢查和臨床環境來懷疑結腸缺血的診斷。如果可能，通常通過腹部 CT 通過影像學檢查來確認。

For patients who present with fulminant gangrenous colonic ischemia with peritonitis and/or colon perforation, a definitive diagnosis will necessarily be made in the operating room. In certain acute settings and for those with chronic symptoms, lower endoscopy (sigmoidoscopy or colonoscopy) is the best diagnostic test to identify colonic ischemia and differentiate it from other causes of abdominal pain and bloody stools. (See 'Abdominal exploration' below and 'Abdominal imaging' below and 'Lower endoscopy' below.)
對於暴發性壞疽性結腸缺血伴腹膜炎和/或結腸穿孔的患者，必須在手術室做出明確診斷。在某些急性情況下和有慢性癥狀的患者，下內鏡檢查（乙狀結腸鏡檢查或結腸鏡檢查）是識別結腸缺血並將其與其他原因引起的腹痛和血便區分開來的最佳診斷測試。（參見下文 '腹部探查' 和 '腹部影像學檢查' 和 '下消化道內鏡檢查'）

While plain abdominal radiographs are frequently obtained in the evaluation of abdominal pain, findings are nonspecific. Distension or pneumatosis (image 1) is typically seen only with advanced ischemia. In one series of 23 cases, signs such as thumbprinting (indicating submucosal edema) (image 2) and hemorrhage could be identified in only 30 percent of patients with mesenteric infarction [69]. When plain radiographic findings suggest ischemia, they may portend a worse prognosis, as illustrated in one study in which patients with an abnormal abdominal radiograph had a higher mortality rate compared with those without such findings (78 versus 29 percent) [70].
雖然在評估腹痛時經常獲得腹部 X 線平片，但結果是非特異性的。腹脹或充氣 （ 影像 1） 通常僅見於晚期缺血。一項系列研究納入 23 例，只有 30%的腸系膜梗死患者可發現拇指紋（提示黏膜下水腫）（ 影像 2）和出血等體征[69]。當 X 線片平片提示缺血時，可能預示著預後更差，一項研究顯示，與無缺血檢查結果的患者相比，腹部 X 線片異常患者的死亡率更高（78% vs 29%）[70]。

Abdominal imaging — CT of the abdomen with intravenous contrast (and oral contrast if tolerated by the patient) is typically the first imaging study obtained in patients presenting acutely with features of intestinal ischemia (algorithm 1). CT findings are nonspecific, and scans can initially be normal [71-73]. Typical findings include edema and thickening of the bowel wall in a segmental pattern (thumbprinting (image 3) or "target" or "double-halo" appearance from hyperdensity of the mucosa and muscularis). These changes typically reflect the initial episode of transient ischemia and subsequent reperfusion injury rather than ongoing ischemia. However, they are not specific for ischemia and can be seen in infectious colitis such as from C. difficile or Crohn colitis. Other findings on CT scans may include irregular bowel contours, mesenteric inflammation with stranding of the fat, or free peritoneal fluid [74,75].
腹部影像學檢查  —  靜脈造影劑（如果患者耐受，則為口腔造影劑）的腹部 CT 通常是首次在急性表現為腸缺血特徵的患者中進行影像學檢查 （ 流程圖 1）。CT 表現為非特異性，掃描最初可能正常[71-73]。典型表現包括水腫和腸壁節段性增厚（指紋 （影像 3）或黏膜和肌層高密度導致的“目標”或“雙暈”外觀）。這些變化通常反映的是短暫性腦缺血的初始發作和隨後的再灌注損傷，而不是持續的缺血。然而，它們對缺血沒有特異性，可以在傳染性結腸炎中看到，例如艱難梭菌或克羅恩結腸炎。CT 掃描的其他發現可能包括腸道輪廓不規則、腸系膜炎症伴脂肪擱淺或遊離腹膜液[74,75]。

Nevertheless, CT can differentiate colonic ischemia from nonischemic causes of abdominal pain or may suggest irreversible ischemia/transmural infarction (eg, colonic necrosis, perforation, extramural or portomesenteric venous gas) that indicates the need for colon resection [74-76]. Pneumatosis coli (image 3), gas in the mesenteric or portal veins, or pneumoperitoneum indicating perforation may be seen in the more advanced stages, but these findings are not specific to colonic ischemia. Hepatic portal venous gas is a rare radiographic finding that has been associated with bowel necrosis, particularly in patients with additional clinical and radiographic evidence of necrotic bowel [77]. However, pneumatosis coli and portal venous gas can also be detected in benign situations (eg, after surgical or endoscopic manipulation). Standard CT imaging may also identify major arterial embolic or venous obstruction more consistent with acute mesenteric ischemia (eg, colonic involvement isolated to the right side). If major vascular occlusion is suspected, CT angiography may be the more appropriate initial imaging study. (See 'Large versus small bowel ischemia' below and "Acute mesenteric arterial occlusion".)
然而，CT 可以鑒別結腸缺血和腹痛的非缺血性原因，或可能提示不可逆的缺血/透壁梗死（如結腸壞死、穿孔、壁外或門外腸內靜脈氣體），提示需要結腸切除術[74-76]。大腸肺炎 （ 影像 3）、腸系膜或門靜脈脹氣或氣腹可能出現在更晚期的病期，但這些表現並非結腸缺血所特有。肝門靜脈氣體是一種罕見的影像學表現，與腸壞死有關，特別是在有其他臨床和影像學證據為壞死腸的患者中[77]。然而，在良性情況下（例如，手術或內鏡作后）也可以檢測到大腸肺病和門靜脈氣體。標準 CT 影像學檢查還可識別出與急性腸系膜缺血更一致的嚴重動脈栓塞或靜脈梗阻（如，結腸受累孤立於右側）。如果懷疑主要血管閉塞，CT 血管造影可能是更合適的初始影像學檢查。（參見下文 '大腸缺血 vs 小腸缺血' 和 “急性腸系膜動脈閉塞”）

Conventional catheter-based arteriography is much less useful in the diagnosis of colonic ischemia. Ischemic changes are typically limited to the arteriolar vessels and are rarely seen since nonocclusive ischemia is a more common etiology and because, with resuscitation, colonic blood flow has often returned to normal levels. In the absence of instrumentation or aortoiliac surgery, the major mesenteric vessels and vascular arcades are usually patent. Nevertheless, catheter-based arteriography may be necessary if the diagnostic evaluation cannot exclude concomitant right colonic small bowel ischemia and lower endoscopy is not revealing. A subset of patients in whom the presentation of colonic ischemia is a heralding sign of acute mesenteric ischemia (eg, severe pain without bleeding with risk factors for arterial mesenteric occlusion) may require catheter-based arteriography to establish the diagnosis. (See 'Large versus small bowel ischemia' below and "Acute mesenteric arterial occlusion", section on 'Presentation and evaluation'.)
傳統的基於導管的動脈造影在結腸缺血的診斷中用處要小得多。缺血性改變通常局限於小動脈血管，很少見，因為非閉塞性缺血是一種更常見的病因，並且通過復甦，結腸血流通常已恢復到正常水準。在沒有器械或主髂手術的情況下，主要腸系膜血管和血管拱門通常是通暢的。然而，如果診斷評估不能排除伴隨的右結腸小腸缺血，並且下內鏡檢查沒有顯示，則可能需要基於導管的動脈造影。部分患者以結腸缺血為急性腸系膜缺血的預兆徵象（如，劇烈疼痛無出血，伴有動脈腸系膜閉塞的危險因素），可能需要導管動脈造影術才能確診。（參見下文 '大腸缺血 vs 小腸缺血' 和 “急性腸系膜動脈閉塞”，關於'表現和評估'一節 ）

Lower endoscopy — Colonoscopy or sigmoidoscopy confirms the diagnosis of colonic ischemia and should be performed in all patients suspected with colonic ischemia, if possible (algorithm 2). Lower endoscopy should be performed with minimal air insufflation to avoid excessive distention that could lead to colon perforation [78]. If colonic ischemia is suspected, the study should be performed earlier (within 48 hours) rather than later following initial presentation [4,79] but should not be performed in patients with acute peritonitis on physical examination or evidence of irreversible ischemic damage on imaging studies. (See "Overview of colonoscopy in adults".)
下內鏡檢查  —  結腸鏡檢查或乙狀結腸鏡檢查可確診為結腸缺血，如果可能，應對所有疑似結腸缺血的患者進行結腸鏡檢查 （ 流程圖 2）。下內鏡檢查時應盡量減少吹氣，以避免過度擴張，從而導致結腸穿孔[78]。如果懷疑結腸缺血，應在初次就診后更早（48 小時內）進行研究，而不是晚些時候進行[4,79]，但對於體格檢查顯示急性腹膜炎患者或影像學檢查顯示有不可逆缺血性損傷證據的患者，不應進行檢查。（參見 “成人結腸鏡檢查概述”）

Colonoscopy is sensitive for detecting mucosal lesions, permits biopsy of suspicious areas (picture 1), and does not interfere with subsequent arteriography. Colonoscopy may disclose ischemic colitis but cannot separate transmural from the clinically less important mucosal ischemia [79]. Some vascular surgeons recommend serial sigmoidoscopic examinations in patients in whom the bowel was considered to be at risk following aortic surgery [79]. However, no study has demonstrated that this approach is associated with improved survival [39,60,79].
結腸鏡檢查對發現黏膜病變很敏感，可以對可疑區域進行活檢 （ 圖片 1），並且不會干擾後續動脈造影。結腸鏡檢查可發現缺血性結腸炎，但不能將透壁與臨床上不太重要的粘膜缺血區分開來[79]。一些血管外科醫生建議對主動脈手術后腸道有風險的患者進行連續乙狀結腸鏡檢查[79]。然而，沒有研究表明這種方法與提高生存率有關[39,60,79]。

Colonoscopic findings in the acute setting frequently include edematous, friable mucosa, erythema, and interspersed pale areas (picture 2) [80]. Bluish hemorrhagic nodules may be seen representing submucosal bleeding; these are the equivalent of "thumbprints" detected in radiologic studies. More severe disease is marked by cyanotic mucosa and scattered hemorrhagic erosions or linear ulcerations. Occasional patients have pseudomembranous colitis with yellowish round plaques or confluent membranes not related to C. difficile infection [81]. Ischemia rather than inflammatory bowel disease is suggested by segmental distribution, abrupt transition between injured and noninjured mucosa, and rectal sparing. A single linear ulcer running along the longitudinal axis of the colon (the "single-stripe sign") may also favor an ischemic cause of colitis (picture 2) [82].
急性結腸鏡檢查結果常包括水腫、黏膜易碎、紅斑和散在的臉色蒼白 （ 圖片 2）[80]。可見藍色出血性結節代表黏膜下出血;這些相當於放射學研究中檢測到的“指紋”。更嚴重的疾病以粘膜紫紺和散在的出血性糜爛或線性潰瘍為特徵。偶有患者出現偽膜性結腸炎，伴有與艱難梭菌感染無關的淡黃色圓形斑塊或匯合膜[81]。節段分佈、受傷和非受傷粘膜之間的突然轉變以及直腸保留提示缺血而不是炎症性腸病。沿結腸縱軸延伸的單個線狀潰瘍（“單條紋征”）也可能有利於結腸炎的缺血性病因 （ 圖片 2）[82]。

Biopsies taken from affected areas may show nonspecific changes such as hemorrhage, crypt destruction, capillary thrombosis, granulation tissue with crypt abscesses, and pseudopolyps (picture 3), which may mimic Crohn disease [83,84]. In the chronic phase of ischemic colitis, mucosal atrophy and areas of granulation tissue may be found. Biopsy of a postischemic stricture is marked by extensive transmural fibrosis and mucosal atrophy.
從患處採集的活檢可能顯示非特異性改變，如出血、隱窩破壞、毛細血管血栓形成、肉芽組織伴隱窩膿腫和假性息肉 （ 圖片 3），這些變化可能與克羅恩病相似[83,84]。在缺血性結腸炎的慢性期，可能會發現粘膜萎縮和肉芽組織區域。缺血后狹窄的活檢以廣泛的透壁纖維化和粘膜萎縮為特徵。

DIFFERENTIAL DIAGNOSIS  鑒別診斷 — 

The differential diagnosis of colonic ischemia is broad and includes small bowel ischemia, infectious colitis, inflammatory bowel disease, and a myriad of other causes for abdominal pain and lower gastrointestinal bleeding. (See "Etiology of lower gastrointestinal bleeding in adults" and "Causes of abdominal pain in adults".)
結腸缺血的鑒別診斷範圍很廣，包括小腸缺血、感染性結腸炎、炎症性腸病以及無數其他導致腹痛和下消化道出血的原因。（參見 “成人下消化道出血的病因” 和 “成人腹痛的病因”）

Large versus small bowel ischemia — Several clinical features distinguish acute colonic ischemia from acute mesenteric ischemia involving the small bowel (table 3) [6,10,56]. The distinction may also be apparent in imaging studies. (See "Overview of intestinal ischemia in adults".)
大腸缺血 vs 小腸缺血  —  急性結腸缺血與累及小腸的急性腸系膜缺血有若干臨床特徵 （ 表 3）[6,10,56]。這種區別在影像學研究中也可能很明顯。（參見 “成人腸缺血概述”）

●Severe pain is more likely for acute ischemia involving the small bowel compared with the colon, for which extreme pain is usually not as prominent a feature.
與結腸相比，累及小腸的急性缺血更容易出現劇烈疼痛，而結腸的極度疼痛通常不那麼突出。

●The onset of pain is sudden when ischemia is caused by embolic disease. In contrast, the pain may occur more insidiously (hours to days) in patients with thrombotic causes, vasculitis, or nonocclusive ischemia.
當缺血是由栓塞性疾病引起的時，疼痛的發作是突然的。相反，在血栓性、血管炎或非閉塞性缺血的患者中，疼痛可能更隱匿（數小時至數天）。

●In patients with small bowel obstruction leading to ischemia, pain often precedes vomiting.
在導致缺血的小腸梗阻患者中，疼痛通常先於嘔吐。

●Hematochezia is more commonly a sign of colonic ischemia compared with small bowel ischemia.
與小腸缺血相比，便血更常見於結腸缺血的徵象。

Chronic ischemic colitis is rarely confused with chronic mesenteric ischemia. (See "Chronic mesenteric ischemia".)
慢性缺血性結腸炎很少與慢性腸系膜缺血相混淆。（參見 “慢性腸系膜缺血”）

Other — The differential diagnosis of colonic ischemia also includes infectious colitis, inflammatory bowel disease, diverticulitis, radiation enteritis, solitary rectal ulcer syndrome, and colon carcinoma [85,86]. (See "Approach to the adult with acute diarrhea in resource-abundant settings".)
其他  —  結腸缺血的鑒別診斷還包括感染性結腸炎、炎症性腸病、憩室炎、放射性腸炎、孤立性直腸潰瘍綜合征和結腸癌[85,86]。（參見 “資源豐富地區成人急性腹瀉的概述”）

Infection with Klebsiella oxytoca has been associated with right-sided hemorrhagic colitis that can mimic ischemic colitis. This rare infection occurs in patients exposed to antibiotics, particularly penicillin derivatives [87,88]. Diagnosis is established by culture. (See "Microbiology and pathogenesis of Klebsiella pneumoniae infection".)
催產克雷伯菌感染與可模仿缺血性結腸炎的右側出血性結腸炎有關。這種罕見的感染發生在抗生素暴露的患者中，尤其是青黴素衍生物[87,88]。診斷是通過培養確定的。（參見 “肺炎克雷伯菌感染的微生物學和發病機制”）

C. difficile infection should be excluded in hospitalized patients exposed to antibiotics. This infection produces marked thickening of the colon on CT scans, as well as very high total white blood cell counts, which resemble the findings of ischemic colitis. Although occult blood may be detected in diarrheal stools of symptomatic patients, grossly bloody stools are quite rare in C. difficile infection. (See "Clostridioides difficile infection in adults: Clinical manifestations and diagnosis".)
在暴露於抗生素的住院患者中，應排除艱難梭菌感染。這種感染在 CT 掃描中導致結腸明顯增厚，以及非常高的白細胞總計數，類似於缺血性結腸炎的發現。雖然在有癥狀患者的腹瀉便中可能會檢測到潛血，但在艱難梭菌感染中，嚴重血便非常罕見。（參見 “成人艱難梭菌感染的臨床表現和診斷”）

Patients with chronic ischemic colitis who are misdiagnosed as having inflammatory bowel disease will respond poorly to immunosuppressive therapy and have an increased risk of perforation on steroids.
被誤診為炎症性腸病的慢性缺血性結腸炎患者對免疫抑制治療反應不佳，類固醇穿孔的風險增加。

TREATMENT  治療

Treatment overview — Treatment of acute colonic ischemia depends upon its etiology, severity, and the clinical setting (algorithm 2). Most patients with colonic ischemia will resolve with supportive care and do not require specific therapy. For patients who do progress to irreversible ischemia, timely diagnosis and treatment can significantly decrease the morbidity and mortality of the postoperative clinical course. Surgical intervention is best performed before the onset of hemodynamic instability, colon perforation, or frank colon necrosis.
治療概述  —  急性結腸缺血的治療取決於其病因、嚴重程度和臨床情況 （ 流程圖 2）。大多數結腸缺血患者會通過支持治療消退，不需要特殊治療。對於確實進展為不可逆缺血的患者，及時診斷和治療可以顯著降低術后臨床病程的發病率和死亡率。手術干預最好在血流動力學不穩定、結腸穿孔或明顯結腸壞死發作之前進行。

The American College of Gastroenterology has proposed a risk stratification that may assist with determining the appropriate treatment [1]. The risk factors associated with a poor outcome include male sex, hypotension (systolic blood pressure <90 mmHg), tachycardia (heart rate >100 beats/minute), abdominal pain without rectal bleeding, blood urea nitrogen (BUN) >20 mg/dL, hemoglobin (Hb) <12 g/dL, lactate dehydrogenase (LDH) >350 units/L, serum sodium <136 mEq/L (mmol/L), and white blood cell count >15,000 cells/microliter. The risk categories are:
美國胃腸病學會（American College of Gastroenterology）提出了一種風險分層，可能有助於確定適當的治療方法[1]。與不良結果相關的危險因素包括男性、低血壓（收縮壓 <90 mmHg）、心動過速（心率 >100 次/分鐘）、腹痛無直腸出血、血尿素氮 （BUN） >20 mg/dL、血紅蛋白 （Hb） <12 g/dL、乳酸脫氫酶 （LDH） >350 單位/L、血清鈉 <136 mEq/L （mmol/L） 和白細胞計數 >15，000 個細胞/微升。風險類別包括：

●Mild colonic ischemia – Suspected colonic ischemia based upon typical symptoms and advanced abdominal imaging or lower endoscopy consistent with colonic ischemia but with no risk factors associated with a poor outcome. The patient has no clinical signs that would indicate the need for immediate exploration. (See 'Supportive care' below.)
輕度結腸缺血 – 根據典型癥狀和晚期腹部影像學檢查或下內鏡檢查，疑似結腸缺血，與結腸缺血一致，但沒有與不良結局相關的危險因素。患者沒有表明需要立即探索的臨床癥狀。（參見下文 '支持治療'）

●Moderate colonic ischemia – Suspected colonic ischemia based upon typical symptoms and advanced abdominal imaging or lower endoscopy consistent with colonic ischemia and up to three risk factors associated with a poor outcome. The patient has no clinical signs that would indicate the need for immediate exploration. (See 'Antibiotics' below and 'Antithrombotic therapy' below.)
中度結腸缺血 – 根據典型癥狀和與結腸缺血一致的晚期腹部影像學檢查或下內鏡檢查以及與不良預後相關的多達三個危險因素，疑似結腸缺血。患者沒有表明需要立即探索的臨床癥狀。（參見下文 '抗生素' 和 '抗血栓治療'）

●Severe colonic ischemia – Suspected colonic ischemia based upon typical symptoms and more than three of the criteria for moderate disease or any of the following: peritoneal signs on physical examination; pneumoperitoneum, pneumatosis, or portal venous gas on radiologic imaging; gangrene on colonoscopic examination. Chronic hemodialysis or poor Eastern Cooperative Oncology Group status are also independent risk factors for severe disease [89]. (See 'Abdominal exploration' below.)
嚴重結腸缺血 – 根據典型癥狀和三個以上的中度疾病標準或以下任何一項懷疑結腸缺血：體格檢查時有腹膜體征;放射成像上的氣腹、氣腫或門靜脈氣體;結腸鏡檢查壞疽。慢性血液透析或東部腫瘤合作組狀態不佳也是重症的獨立危險因素[89]。（參見下文 '腹部探查'）

Supportive care  支援性治療

●Supportive care with bowel rest and observation is appropriate, provided there is no evidence of colon perforation, necrosis, or gangrene. Intravenous fluids should be given to ensure adequate colonic perfusion.
如果沒有結腸穿孔、壞死或壞疽的證據，則支援性治療包括腸道休息和觀察是適當的。應給予靜脈輸液以確保足夠的結腸灌注。

●A nasogastric tube should be inserted if an ileus is present. Any precipitating conditions should be treated, and medications known to promote intestinal ischemia (eg, vasopressors, digitalis) should be promptly discontinued (table 1) if feasible. Cardiac function and oxygenation should be optimized.
如果存在腸梗阻，應插入鼻胃管。任何誘發疾病時，應進行治療，如果可行，應立即停用已知會促進腸缺血的藥物（如血管加壓藥、洋地黃） （ 表 1）。應優化心臟功能和氧合。

●The patient should be monitored for persistent fever, leukocytosis, peritoneal irritation, protracted diarrhea, or gastrointestinal bleeding. If clinical deterioration is evident despite conservative therapy, diagnostic laparoscopy or laparotomy is indicated. (See 'Abdominal exploration' below.)
應監測患者是否有持續發熱、白細胞增多、腹膜刺激、長期腹瀉或消化道出血。如果保守治療后臨床惡化明顯，則需要進行診斷性腹腔鏡檢查或剖腹手術。（參見下文 '腹部探查'）

●Most patients with nonocclusive colonic ischemia improve within one or two days and have complete clinical and radiologic resolution within one to two weeks. Patients with a prolonged course may require nutritional support.
大多數非閉塞性結腸缺血患者在一到兩天內好轉，並在一到兩周內完全消退臨床和影像學消退。病程延長的患者可能需要營養支援。

●The patient should be monitored for persistent fever, leukocytosis, peritoneal irritation, protracted diarrhea, or gastrointestinal bleeding. If clinical deterioration is evident despite conservative therapy, abdominal exploration is indicated. (See 'Abdominal exploration' below.)
應監測患者是否有持續發熱、白細胞增多、腹膜刺激、長期腹瀉或消化道出血。如果保守治療后臨床惡化明顯，則需要進行腹部探查。（參見下文 '腹部探查'）

●Severe ischemia can cause ulceration and inflammation, which, over time, may develop into a stricture or chronic ischemic colitis. These lesions may be asymptomatic, but they should be followed to document healing or the development of persistent colitis or stricture, which can cause symptoms of partial bowel obstruction.
嚴重的缺血會導致潰瘍和炎症，隨著時間的推移，可能會發展成狹窄或慢性缺血性結腸炎。這些病變可能無癥狀，但應隨之追蹤以記錄持續性結腸炎或狹窄的癒合或發展，這可能導致部分腸梗阻的癥狀。

Antibiotics — There is no strong evidence supporting the routine use of antibiotics for the treatment of all patients with colonic ischemia. However, we agree with major society guidelines that suggest empiric broad-spectrum antibiotics for most patients with colonic ischemia, except possibly those with mild disease and no evidence of bleeding from ulceration (table 4) [1,90-92]. (See "Antimicrobial approach to intra-abdominal infections in adults".)
抗生素  —  沒有強有力的證據支援常規使用抗生素治療所有結腸缺血患者。然而，我們同意主要的學會指南，即大多數結腸缺血患者應經驗性使用廣譜抗生素，但病情較輕且無潰瘍出血證據的患者除外 （ 表 4）[1,90-92]。（參見 “成人腹腔內感染的抗菌方法”）

This recommendation is based mainly upon an experimental model showing reduced intestinal inflammation and injury with depletion of gut bacteria [93] and upon older studies in which antibiotics reduced the severity and extent of experimental bowel damage when given prior to an ischemic event [94-96]. In addition, some studies suggest that antibiotics theoretically protect against bacterial translocation occurring from loss of mucosal integrity, and animal studies have suggested a potential survival advantage with antibiotics [97-99].
這一建議主要基於一項實驗模型，該模型顯示腸道細菌的消耗可減少腸道炎症和損傷[93]，以及較早的研究，其中在缺血事件發生前給予抗生素可減輕實驗性腸損傷的嚴重程度和程度[94-96]。此外，一些研究表明，抗生素理論上可以防止因黏膜完整性喪失而發生的細菌易位，動物研究表明抗生素具有潛在的生存優勢[97-99]。

Antithrombotic therapy — Antithrombotic therapy is not indicated for most patients with colonic ischemia, as the majority have nonocclusive ischemia. However, anticoagulant therapy is indicated for patients who develop colonic ischemia due to mesenteric venous thrombosis or related to mesenteric thromboembolism (eg, cardiac source). (See "Mesenteric venous thrombosis in adults", section on 'Anticoagulation' and "Acute mesenteric arterial occlusion", section on 'Management'.)
抗血栓治療  —  大多數結腸缺血患者不適用於抗血栓治療，因為大多數患者為非閉塞性缺血。然而，抗凝治療適用於因腸系膜靜脈血栓形成或腸系膜血栓栓塞相關（如心臟源）而發生結腸缺血的患者。（參見 “成人腸系膜靜脈血栓形成”，關於'抗凝'一節和 “急性腸系膜動脈閉塞”，關於'治療'一節 ）

Recanalization of thrombosed mesenteric veins has been described following long-term anticoagulant therapy [100,101]. In addition to systemic anticoagulation, patients with mesenteric vein thrombosis should be evaluated for hypercoagulability. (See "Evaluating adult patients with established venous thromboembolism for acquired and inherited risk factors" and "Mesenteric venous thrombosis in adults", section on 'Anticoagulation'.)
長期抗凝治療后，血栓形成的腸系膜靜脈再通已有報導[100,101]。除了全身抗凝治療外，腸系膜靜脈血栓形成患者還應評估高凝狀態。（參見 “評估已確定靜脈血栓栓塞的成人患者的獲得性和遺傳性危險因素” 和 “成人腸系膜靜脈血栓形成”，關於'抗凝'一節 ）

Antiplatelet agents have not been well studied in this setting and are generally not indicated in those without known peripheral vascular disease. (See "Chronic mesenteric ischemia", section on 'Management'.)
抗血小板藥物尚未在這種情況下得到充分研究，通常不適用於沒有已知外周血管疾病的患者。（參見 “慢性腸系膜缺血”，關於'治療'一節 ）

Ongoing monitoring and counseling — Close follow-up is important for preventing recurrent episodes of ischemic colitis. The patient should be counseled to avoid dehydration, constipation, and overly aggressive treatment of hypertension, particularly in the setting of illness or exercise, to maintain normal blood pressure for optimal colon perfusion. Medications should be reviewed. Recurrent episodes of bacteremia or sepsis associated with unhealed areas of segmental colitis should be referred for elective segmental colon resection.
持續監測和諮詢  —  密切隨訪對於預防缺血性結腸炎復發非常重要。應建議患者避免脫水、便秘和過度積極的高血壓治療，尤其是在生病或運動的情況下，以維持正常血壓以獲得最佳結腸灌注。應審查藥物。與節段性結腸炎未癒合區域相關的菌血症或膿毒癥的復發應轉診進行擇期節段性結腸切除術。

It remains unclear which, if any, patients with colonic ischemia should undergo evaluation for hypercoagulability. Routine evaluation for hypercoagulability is not necessary but may be reasonable in younger patients (<40 years of age) and those with recurrent colonic ischemia. For those identified with hematologic abnormalities, management must be individualized, taking into consideration the specific abnormality, the course and severity of colonic ischemia, whether colon resection was performed, and whether mesenteric venous thrombosis was identified. (See 'Uncertain role of hypercoagulability' above.)
目前尚不清楚哪些結腸缺血患者（如果有）應接受高凝狀態評估。高凝狀態的常規評估不是必需的，但對於年輕患者（<40 歲）和復發性結腸缺血患者可能是合理的。對於發現血液學異常的患者，必須個體化治療，考慮具體異常、結腸缺血的病程和嚴重程度、是否進行結腸切除術以及是否確定腸系膜靜脈血栓形成。（參見上文 '高凝狀態的不確定作用'）

Abdominal exploration — Surgery is required in up to 20 percent of cases [17]. Patients with colon infarction and necrosis require urgent surgical intervention, which can be life-saving [102]. Clinical suspicion of ischemia (eg, ongoing pain that is out of proportion to clinical examination, hemodynamic instability) is a common indication for surgical exploration. Other indications for abdominal exploration include radiologic evidence of bowel necrosis or lesser degrees of ischemia in patients who do not respond appropriately to nonsurgical supportive care [17]. (See 'Supportive care' above.)
腹部探查  —  高達 20%的病例需要手術[17]。結腸梗死和壞死患者需要緊急手術干預，這可以挽救生命[102]。臨床懷疑缺血（如，持續性疼痛與臨床檢查不成比例、血流動力學不穩定）是手術探查的常見指征。腹部探查的其他指征包括非手術支援治療無適當反應的患者有腸壞死或較輕程度缺血的影像學證據[17]。（參見上文 '支持治療'）

Prior to abdominal exploration (open or laparoscopic), bowel preparation should not be used, as it can precipitate perforation or toxic dilation of the colon.
在腹部探查（開放或腹腔鏡）之前， 不應使用腸道準備，因為它會誘發結腸穿孔或毒性擴張。

For patients whose imaging and colonoscopy have not clearly defined the extent of ischemia and who do not have contraindications, laparoscopic exploration may be appropriate to confirm the diagnosis prior to open exploration [103]. In experienced hands, laparoscopic colectomy, if indicated, is an option and can be done quite efficiently and avoids major wound complications. A concern with laparoscopy is the effect of pneumoperitoneum on mesenteric blood flow [104]. The intraperitoneal pressure should be lowered (approximately 10 mmHg) in those suspected with suspected mesenteric ischemia. (See "Overview of colon resection" and "Complications of laparoscopic surgery", section on 'Related to pneumoperitoneum'.)
對於影像學檢查和結腸鏡檢查未明確缺血程度且無禁忌證的患者，腹腔鏡探查可能適合在開放式探查前確診[103]。在有經驗的手中，腹腔鏡結腸切除術（如果有指征）是一種選擇，可以非常有效地完成並避免嚴重的傷口併發症。腹腔鏡檢查的一個問題是氣腹對腸系膜血流的影響[104]。對於疑似腸系膜缺血的患者，應降低腹膜內壓（約 10 mmHg）。（參見 “結腸切除術概述” 和 “腹腔鏡手術的併發症”，關於'氣腹相關'一節 ）

Once the abdomen is exposed (open or laparoscopic), the bowel should be systematically inspected from the ligament of Treitz to the peritoneal reflection overlying the rectum. The serosal surface of the intestines may appear normal in early or mild ischemia. With more advanced ischemia, dark peritoneal fluid may be present in the paracolic gutters or within the pelvis. Overtly, the ischemic bowel will appear edematous with patchy areas of serosal hemorrhage or gangrenous changes with or without perforation. Intraoperative colonoscopy can be used to assess the extent of ischemia.
一旦腹部暴露（開放或腹腔鏡），應系統地檢查腸道，從 Treitz 韌帶到直腸上方的腹膜反射。腸道漿膜表面在早期或輕度缺血時可能看起來正常。對於更嚴重的缺血，深色腹膜液可能存在於結腸旁排水溝或骨盆內。明顯地，缺血性腸會出現水腫，伴有斑片狀漿膜出血區域或壞疽性變化，伴或不伴穿孔。術中結腸鏡檢查可用於評估缺血的程度。

Specific surgical management depends upon the location of the affected colon. (See "Overview of colon resection".)
具體的手術治療取決於受累結腸的位置。（參見 “結腸切除術概述”）

●Right-sided colonic ischemia and necrosis are managed with resection of the ischemic segment. A decision for ileostomy and transverse colon mucous fistula versus primary ileocolonic anastomosis depends upon the patient's general condition and assessment of the transected ends of the ileum and colon [105].
右側結腸缺血和壞死通過切除缺血節段來治療。迴腸造口術和橫向結腸黏膜瘺與原發性迴結腸吻合術的決定取決於患者的一般情況以及對迴腸和結腸橫切端的評估[105]。

●Depending upon the extent of the ischemia, left-sided colonic ischemia is managed with sigmoid resection or left hemicolectomy, with either a proximal stoma and distal mucous fistula or Hartmann's procedure (figure 5).
根據缺血的程度，左側結腸缺血可採用乙狀結腸切除術或左側半結腸切除術，或近埠和遠端黏膜瘺或 Hartmann 手術 （ 圖 5）。

●The rare patient with a fulminating type of colonic ischemia involving most of the colon and rectum may require subtotal colectomy with terminal ileostomy.
罕見的暴發性結腸缺血患者累及大部分結腸和直腸，可能需要結腸次全切除術和終末迴腸造口術。

Adequate surgical margins that are beyond macroscopically involved regions should be ensured. Primary anastomosis should be avoided in patients with severe colitis or those with hemodynamic instability. Among patients with an open aortic or iliac vascular graft, primary colonic anastomosis is also contraindicated in those who require bowel resection because any subsequent anastomotic leak would contaminate the graft [106].
應確保超出肉眼受累區域的足夠手術切緣。嚴重結腸炎或血流動力學不穩定的患者應避免初次吻合。在開放性主動脈或髂血管移植物的患者中，需要腸切除術的患者也禁用初次結腸吻合術，因為隨後的任何吻合口滲漏都會污染移植物[106]。

When the need for colectomy is identified during laparoscopic exploration, those familiar with the technique can perform it. (See "Overview of colon resection".)
當在腹腔鏡探查過程中確定需要進行結腸切除術時，熟悉該技術的人可以進行。（參見 “結腸切除術概述”）

Second-look procedure — Rarely, following exploration or colonic resection, repeat exploration (ie, "second-look" operation [open or laparoscopic]) should be performed within 12 to 24 hours to assess the viability of the remaining bowel and integrity of any anastomoses [105,107].
二次檢查  —  在極少數情況下，在探查或結腸切除術后，應在 12-24 小時內進行重複探查（即“二次檢查”手術[開腹或腹腔鏡]），以評估剩餘腸的活力和任何吻合口的完整性[105,107]。

Leaving the abdomen open may be needed if abdominal closure will lead to increased intra-abdominal pressure and facilitates the second-look procedure. (See "Management of the open abdomen in adults".)
如果腹部閉合會導致腹內壓升高並促進二次檢查，則可能需要保持腹部打開。（參見 “成人開腹的治療”）

Vascular intervention — Local infusion of vasodilators (such as papaverine) can attenuate vasospasm, but systemic side effects often limit its use in patients with nonocclusive colonic ischemia. Vasodilatory therapy is discussed in more detail elsewhere. (See "Nonocclusive mesenteric ischemia", section on 'Vasodilator infusion'.)
血管介入治療  —  局部輸注血管擴張劑（如罌粟鹼 ）可減輕血管痙攣，但全身副作用通常限制其在非閉塞性結腸缺血患者中的使用。血管舒張治療詳見其他專題。（參見 “非閉塞性腸系膜缺血”，關於'血管擴張劑輸注'一節 ）

Among patients with embolic or thrombotic arterial occlusion, pharmacomechanical thrombolysis with or without mesenteric angioplasty and stenting may be indicated. (See "Surgical and endovascular techniques for mesenteric revascularization".)
在栓塞性或血栓性動脈閉塞患者中，可能需要進行藥物力學溶栓聯合或不聯合腸系膜血管成形術和支架置入術。（參見 “腸系膜血運重建的手術和血管內技術”）

As a general rule, unlike mesenteric ischemia, embolectomy, bypass graft, or endarterectomy is not performed in cases of primary colonic ischemia, which is not generally related to large artery obstruction.
一般來說，與腸系膜缺血不同，原發性結腸缺血不進行栓子切除術、旁路移植術或動脈內膜切除術，原發性結腸缺血通常與大動脈阻塞無關。

Handling the inferior mesenteric artery during aortic surgery is reviewed separately. (See "Open surgical repair of abdominal aortic aneurysm", section on 'Handling the inferior mesenteric artery'.)
主動脈手術中腸系膜下動脈的處理詳見其他專題。（參見 “腹主動脈瘤的開放手術修復術”，關於'腸系膜下動脈的處理'一節 ）

POSTOPERATIVE CARE AND FOLLOW-UP
術后護理和隨訪 — 

Following abdominal exploration or colon resection, the patient should be returned to an intensive care setting for hemodynamic support and monitoring.
腹部探查或結腸切除術后，應將患者送回重症監護室接受血流動力學支持和監測。

For patients who have undergone colectomy requiring ileostomy or colostomy, ostomy closure should be delayed for four to six months. Given the risk factors that lead to colonic ischemia, it is apparent that this subgroup of patients is older and likely frailer with a higher risk for subsequent surgery. Up to two-thirds of patients never proceed to reversal because of comorbid conditions [17,108]. In-hospital mortality related to elective ostomy reversal was 18 percent in one study, with 35 percent of patients requiring prolonged postoperative intensive care admission [109].
對於接受過需要迴腸造口術或結腸造口術的結腸切除術患者，造口術應延遲四到六個月。鑒於導致結腸缺血的危險因素，很明顯，這組患者年齡較大，可能更虛弱，後續手術的風險更高。多達 2/3 的患者因合併症而從未逆轉[17,108]。一項研究顯示，與擇期造口逆轉相關的院內死亡率為 18%，35%的患者需要延長術后重症監護期[109]。

MORTALITY  死亡率 — 

The prognosis of patients with ischemic colitis depends upon the etiology, disease severity, distribution, and comorbidities [2,6,31,89-92,109]. Most patients have self-limiting ischemia that typically resolves completely [4]. As a general rule, nongangrenous colonic ischemia is associated with low mortality (<5 percent) [17,110]. The need for surgery increases the rates of morbidity and mortality. Approximately 10 to 20 percent of patients develop colonic necrosis and gangrene, which is associated with high mortality rates [57,92,109].
缺血性結腸炎患者的預後取決於病因、疾病嚴重程度、分佈和合併症[2,6,31,89-92,109]。大多數患者有自限性缺血，通常會完全消退[4]。一般來說，非壞疽性結腸缺血的死亡率較低（<5%）[17,110]。手術的需要增加了發病率和死亡率。約 10%-20%的患者發生結腸壞死和壞疽，這與高死亡率有關[57,92,109]。

A systematic review of 11 studies included 1049 patients [55]. Medical management used in 80 percent of patients was associated with a mortality rate of 6 percent. Medically managed patients had only mucosal and submucosal injury, for which symptoms resolved with conservative measures and no long-term sequelae. Surgical intervention was associated with a 40 percent mortality rate. The difference in mortality reflected predominantly the severity of illness in those who required surgery.
一項系統評價納入了 11 項研究，共納入 1049 例患者[55]。80% 的患者採用的藥物治療與 6% 的死亡率相關。接受藥物治療的患者僅有黏膜和黏膜下損傷，保守措施可緩解癥狀，無長期後遺症。手術干預與 40% 的死亡率相關。死亡率的差異主要反映了需要手術的人的疾病嚴重程度。

In another study of 4548 patients undergoing emergency colectomies for ischemic colitis, 30-day postoperative mortality was 25.3 percent. Preoperative risk factors associated with a higher rate of mortality included older age, poor functional status, multiple comorbidities, septic shock, blood transfusion, acute kidney failure, and the duration of time from hospital admission to surgery [111].
在另一項針對 4548 名因缺血性結腸炎接受緊急結腸切除術的患者進行的研究中，術后 30 天死亡率為 25.3%。與較高死亡率相關的術前危險因素包括年齡較大、功能狀態不佳、多種合併症、膿毒性休克、輸血、急性腎衰竭以及從入院到手術的時間[111]。

In a retrospective review of 273 patients with colonic ischemia, patients with involvement isolated to the right colon had a worse outcome, with a fivefold higher rate of surgery and twofold higher mortality, compared with those with ischemia involving other areas of the colon [112]. Similarly, in a study of 313 patients with biopsy-proven ischemia, patients with left colon ischemia were less likely to require surgery and had a shorter length of stay compared with any other pattern of ischemic colitis [6]. Mortality is higher because colonic ischemia affecting the right side is due to superior mesenteric artery insufficiency and is associated with diffuse small intestinal ischemia and shock; by contrast, left colon ischemia is more likely to be isolated to the inferior mesenteric artery distribution with less associated shock unless there is perforation.
一項回顧性評價納入了 273 例結腸缺血患者，發現與累及結腸其他部位的缺血患者相比，孤立於右結腸受累的患者預後更差，手術率高 5 倍，死亡率高 2 倍[112]。同樣，一項納入 313 例經活檢證實的缺血患者的研究顯示，與任何其他缺血性結腸炎相比，左結腸缺血患者需要手術的可能性較小，住院時間也較短[6]。死亡率較高，因為影響右側的結腸缺血是由於腸系膜上動脈關閉不全所致，並與瀰漫性小腸缺血和休克有關;相比之下，左結腸缺血更有可能孤立於腸系膜下動脈分佈，相關休克較少，除非有穿孔。

SOCIETY GUIDELINE LINKS  學會指南連結 — 

Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Intestinal ischemia".)
來自世界各地選定國家和地區的社會和政府贊助指南的連結另行提供。（參見 “學會指南鏈接：腸缺血”）

INFORMATION FOR PATIENTS
患者資訊 — 

UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
UpToDate 提供兩種類型的患者教育材料，「基礎知識」和“超越基礎知識”。基礎知識患者教育文章是用通俗易懂的語言編寫的，處於 ^{5 至 6 年級}的閱讀水準，它們回答了患者可能對特定病症提出的四到五個關鍵問題。這些文章最適合想要總體概述並喜歡簡短、易於閱讀的材料的患者。超越基礎知識的患者教育文章更長、更複雜、更詳細。這些文章是在 10 ^至 12 ^年級的閱讀水準上寫的，最適合想要深入了解資訊並熟悉一些醫學術語的患者。

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
以下是與此主題相關的患者教育文章。我們鼓勵您將這些主題列印或通過電子郵件發送給您的患者。（您還可以透過搜索“患者資訊”和感興趣的關鍵字來查找有關各種主題的患者教育文章。

●Basics topic (see "Patient education: Ischemic bowel disease (The Basics)")
基礎專題（參見 “缺血性腸病患者教育（基礎篇）”）

SUMMARY AND RECOMMENDATIONS
總結和建議

●Colonic ischemia – Colonic ischemia is the most frequent form of intestinal ischemia, most often affecting older adults. It is due to a reduction in blood flow to a level that is insufficient for the delivery of oxygen and nutrients needed for cellular metabolism. The majority of patients have transient, nongangrenous ischemia, which resolves without sequelae. Some patients develop colonic necrosis and gangrene, which can be life-threatening. Long-term complications include persistent segmental colitis and the development of a stricture. (See 'Introduction' above.)
結腸缺血 – 結腸缺血是最常見的腸缺血形式，最常影響老年人。這是由於血流量減少到不足以輸送細胞代謝所需的氧氣和營養物質的水準。大多數患者為短暫性非壞疽性缺血，消退後無後遺症。一些患者會出現結腸壞死和壞疽，這可能危及生命。長期併發症包括持續性節段性結腸炎和狹窄的發展。（參見上文 '引言'）

●Risk factors – A number of conditions predispose the patient to colonic ischemia (table 1 and table 2); however, colonic ischemia can also develop insidiously with no specific inciting cause identified. (See 'Risk factors' above.)
危險因素 –多種疾病使患者易患結腸缺血 （ 表 1 和表 2）;然而，結腸缺血也可能隱匿地發展，沒有確定特定的誘發原因。（參見上文 '危險因素'）

●Clinical features – The clinical manifestations of colonic ischemia vary depending upon the clinical setting and the extent and duration of the ischemia. Patients with acute colonic ischemia usually present with a rapid onset of mild abdominal pain and tenderness over the affected bowel, most often the left colon. Mild-to-moderate amounts of rectal bleeding or bloody diarrhea usually develop within 24 hours of the onset of abdominal pain. Approximately 20 percent of patients develop chronic ischemic colitis. (See 'Clinical features' above.)
臨床特徵 –結腸缺血的臨床表現因臨床環境以及缺血的範圍和持續時間而異。急性結腸缺血患者通常表現為受累腸道（最常見的是左結腸）出現輕度腹痛和壓痛。輕度至中度直腸出血或血性腹瀉通常在腹痛發作后 24 小時內出現。大約 20% 的患者發展為慢性缺血性結腸炎。（參見上文 '臨床特徵'）

●Diagnosis – Suspicion for colonic ischemia should be increased in patients with risk factors for colonic ischemia and lower abdominal pain and/or blood per rectum. A diagnosis of colonic ischemia can often be made clinically based on history, physical examination, and clinical setting. Lower endoscopy, typically colonoscopy, can confirm a diagnosis of colonic ischemia. CT of the abdomen is useful for excluding alternative diagnoses for abdominal pain. Arteriography is rarely needed but may be useful when the diagnosis is unclear. (See 'Diagnosis' above.)
診斷 –對於有結腸缺血和下腹痛和/或直腸血液危險因素的患者，應增加對結腸缺血的懷疑。結腸缺血的診斷通常可以根據病史、體格檢查和臨床環境進行臨床診斷。下消化道內鏡檢查（通常是結腸鏡檢查）可以確診結腸缺血。腹部 CT 可用於排除腹痛的其他診斷。很少需要動脈造影，但在診斷不明確時可能有用。（參見上文 '診斷'）

●Differential diagnosis – The differential diagnosis includes acute mesenteric ischemia affecting the small intestine, infectious colitis, inflammatory bowel disease, diverticulitis, radiation enteritis, solitary rectal ulcer syndrome, and colon carcinoma. Stool polymerase chain reaction testing for pathogens and Clostridioides difficile should be considered in the appropriate clinical situation. (See 'Differential diagnosis' above.)
鑒別診斷 – 鑒別診斷包括影響小腸的急性腸系膜缺血、感染性結腸炎、炎症性腸病、憩室炎、放射性腸炎、孤立性直腸潰瘍綜合征和結腸癌。在適當的臨床情況下，應考慮對病原體和艱難梭菌進行糞便聚合酶鏈反應檢測。（參見上文 '鑒別診斷'）

●Treatment – Treatment of acute colonic ischemia depends upon its severity and the clinical setting. Supportive care with hemodynamic monitoring in an intensive care unit is appropriate in the absence of colonic gangrene or perforation. Empiric broad-spectrum antibiotics should be given to patients with moderate-to-severe disease. Medications that can promote ischemia should not be given. (See 'Treatment' above.)
治療 – 急性結腸缺血的治療取決於其嚴重程度和臨床環境。在沒有結腸壞疽或穿孔的情況下，在重症監護病房進行血流動力學監測的支援性治療是合適的。中重度患者應經驗性廣譜抗生素。不應給予可促進缺血的藥物。（參見上文 '治療'）

●Prognosis – The prognosis of patients with nonocclusive colonic ischemia depends upon the disease severity, distribution, and comorbidities. Most patients improve within one or two days and have complete resolution within one to two weeks. Patients with underlying comorbidities and those with right-sided ischemic colitis have a worse prognosis. Severe or recurrent ischemia can lead to chronic ischemic colitis or intestinal stricture. (See 'Mortality' above.)
預後 –非閉塞性結腸缺血患者的預後取決於疾病的嚴重程度、分佈和合併症。大多數患者在一到兩天內好轉，並在一到兩周內完全消退。有基礎合併症的患者和右側缺血性結腸炎患者的預後較差。嚴重或復發性缺血可導致慢性缺血性結腸炎或腸狹窄。（參見上文 '死亡率'）