Interobserver Variability in the Evaluation of Chronic Mesenteric Ischemia with Gadolinium-enhanced MR Angiography

RATIONALE AND OBJECTIVES: The purpose of this study was to assess interobserver variability in the interpretation of gadolinium-enhanced magnetic resonance (MR) angiograms of splanchnic vessels in patients suspected of having chronic mesenteric ischemia (CMI). MATERIALS AND METHODS: Two readers blinded to the initial interpretation retrospectively reviewed gadolinium-enhanced MR angiograms obtained for suspected CMI in 26 patients (20 women and six men; age range, 23-77 years; mean age, 61 years) who also underwent conventional angiography. Each reader graded the degree of stenosis based on the percentage diameter reduction of the celiac artery (CA), superior mesenteric artery (SMA), and inferior mesenteric artery (IMA) by using a five-point ordinal scale: 0, no stenosis: 1, mild stenosis (<50%); 2, moderate stenosis (50%-75%); 3, severe stenosis (>75%); 4, occluded artery. Using the conventional angiogram as a reference standard, authors determined sensitivity and specificity for each observer, assigning two thresholds (grades 2 and 3) as significant stenoses. A kappa statistic (kappa) measured interobserver agreement. RESULTS: With grade 2 stenosis used as a threshold, cumulative accuracies for detecting significant stenosis were 0.95 (95% confidence interval, 0.86-0.99) for reader A and 0.97 (0.88-1.0) for reader B. Interobserver agreement for grading proximal splanchnic stenosis was 0.90 for CA, 0.92 for SMA, and 0.48 for IMA. CONCLUSION: Gadolinium-enhanced MR angiography is reproducibly accurate for detection of proximal splanchnic artery stenosis, with good to excellent interobserver agreement.     

Endovascular Treatment of Totally Occluded Superior Mesenteric Artery by Retrograde Crossing via the Villemin Arcade

Chronic mesenteric ischemia (CMI) is a rare disorder that is commonly caused by progressive atherosclerotic stenosis or occlusion of one or more mesenteric arteries. Endovascular treatment for symptomatic CMI represents a viable option, especially in high-operative risk patients. We report a case of acute symptomatic CMI with chronic totally occlusion of the superior mesenteric artery (SMA) associated with significant stenosis of celiac trunk (CT) and inferior mesenteric artery (IMA) that underwent endovascular treatment of all the three mesenteric arteries: stenting of CT and IMA stenosis, and recanalization of the SMA occlusion by retrograde crossing via the Villemin arcade.     

肠系膜上动脉病变 MSCTA 诊断价值

目的：探讨多层螺旋 CT 血管成像(MSCTA)诊断肠系膜上动脉(SMA)病变临床价值。方法回顾性分析40例 SMA病变患者 MSCTA 图像特点,运用容积再现(VR)、多平面重组(MPR)、曲面重组(CPR)及最大密度投影(MIP)等多种后处理重建技术。结果SMA 缺血16例,包括 SMA 急性闭塞8例,其中并发小肠缺血性坏死1例并行坏死小肠切除术。SMA 慢性闭塞8例;孤立性 SMA 夹层10例;SMA 真性动脉瘤7例,感染性心内膜炎相关假性动脉瘤1例;SMA 溃疡3例,其中1例合并肠系膜下动脉(IMA)重度狭窄;腹腔干重度狭窄2例;IMA 闭塞1例。本组40例患者可见 SMA 疾病相关侧支循环13例,4例见于 SMA 慢性闭塞,3例见于 SMA 急性闭塞,1例见于孤立性 SMA 夹层,1例见于 SMA 假性动脉瘤,2例分别见于 IMA 狭窄和闭塞。2例见于腹腔干重度狭窄。其中包括胰十二指肠前、后动脉弓3例,胰背动脉侧支2例、Riolan 弓10例。结论MSCTA 可以清晰观察SMA 各类病变、侧支循环开通情况以及评估肠腔缺血状态。     

内脏动脉狭窄闭塞侧支循环的多层螺旋CT血管成像

目的:探讨腹腔动脉(CA)、肠系膜上动脉(SMA)、肠系膜下动脉(IMA)狭窄闭塞侧支循环在多层螺旋CT血管造影(MSCTA)中的表现.方法:搜集CA、SMA、IMA慢性狭窄闭塞行MSCTA检查的患者80例,采用容积再现(VR)血管添加技术(AV)对侧支血管进行选择性重建.结果:80例慢性期内脏动脉狭窄闭塞患者中SMA...     

Percutaneous Retrograde Recanalization of the Celiac Artery by Way of the Superior Mesenteric Artery for Chronic Mesenteric Ischemia

A 52-year-old man presented with recurrent postprandial abdominal pain, sitophobia, and progressive weight loss. Chronic mesenteric ischemia (CMI) due to subtotal occlusion of the superior mesenteric artery (SMA) and flush occlusion of the celiac artery (CA) was diagnosed. Retrograde recanalization of the CA by way of a collateral channel from the SMA was performed using contemporary recanalization equipment. The CA and SMA were then stented, resulting in sustained resolution of CMI-related symptoms.     

肝癌合并腹腔动脉与肠系膜上动脉侧支循环通路假性闭塞(附12例报告)

目的：探讨肝癌合并腹腔动脉与肠系膜上动脉侧支循环通路假性闭塞的血管造影表现及其在介入治疗中的价值。方法：回顾性分析12例该类患者的肠系膜上动脉造影，腹腔动脉造影及介入治疗资料。结果：12例假性闭塞中，位于肝总动脉与腹腔动脉分叉处6例，肝总动脉分出胃十二指肠动脉支处5例，1例右肝动脉直接起源于腹腔动脉，并在其分叉处发生假性闭塞。在这12处假性闭塞中，于腹腔动脉造影时呈闭塞状态，而肠系膜上动脉造影却完全通畅，似静脉瓣样。并且导丝、导管能顺利通过该闭塞处。10例患者完成了肝动脉化疗栓塞术。结论：这一少见现象可能与其血液动力学改变和解剖学变异有关，了解此征象对于指导介入治疗有一定价值。     

Preoperative Embolization of the Celiac Axis or Common Hepatic Artery before Distal Pancreatectomy with Resection of the Celiac Axis

Patients with locally advanced pancreatic cancer who undergo distal pancreatectomy with resection of the celiac axis (CA) are at risk for postoperative hepatic or gastric ischemia if collateral blood flow from the superior mesenteric artery (SMA) via the gastroduodenal artery is insufficient. This study presents a technique for preoperative angiographic evaluation of these collateral vessels by using an AMPLATZER Vascular Plug to temporarily occlude the CA or common hepatic artery while simultaneously performing digital subtraction angiography of the SMA. If collateral vessels are deemed sufficient, the plug can subsequently be released for permanent occlusion with the intent to enhance the blood flow in these collateral vessels.     

Diagnosis and treatment of inferior mesenteric arterial endoleaks after endovascular repair of abdominal aortic aneurysms

PURPOSE: To review the incidence and repair of inferior mesenteric arterial (IMA) type II endoleaks after endovascular repair of abdominal aortic aneurysms. MATERIALS AND METHODS: Fifty patients who underwent endovascular repair of abdominal aortic aneurysms were examined. If an endoleak was identified at 30-day postoperative computed tomography, conventional arteriography was performed to identify and eliminate its source. After the exclusion of attachment site leaks, a catheter was placed selectively in the superior mesenteric artery (SMA). If retrograde filling of the IMA and aneurysm was identified, coil embolization was attempted through the SMA and middle colic artery. Intrasac pressures were measured at embolization. RESULTS: Eight of 50 patients (16%) had type II endoleaks that were attributed to retrograde flow in the IMA. Intrasac measurements demonstrated systemic pressure in six patients and one-half systemic pressure in two patients. The IMA was embolized through the SMA and left colic artery in seven patients and through the translumbar aorta in one patient. CONCLUSION: Retrograde flow in the IMA is responsible for many type II endoleaks. Systemic pressures are transmitted into the aneurysm sac from the IMA. The IMA can be embolized successfully with an SMA approach in most patients.     

Contrast-enhanced MR angiography in patients with aortic occlusion (Leriche syndrome)

The diagnostic utility of contrast-enhanced three-dimensional magnetic resonance angiography (3D MRA) was retrospectively evaluated in 24 patients with Leriche syndrome. 3D MRA was performed either of the abdomen alone (n = 6), the abdomen and chest (n = 2), the abdomen and lower extremities (n = 12), or of all stations (n = 4). MRA image sets were evaluated regarding the location of the aortic occlusion, the presence of concomitant occlusive disease affecting the renal and visceral arteries, the type and extent of collateralization, and the level of the most proximal graftable arterial segments. Intravenous digital subtraction angiography was available for correlation in two patients, while surgical correlation was possible in 14 patients. MRA permitted classification of the level of aortic occlusion as juxtarenal (n = 8), infrarenal, and cranial to the origin of the inferior mesenteric artery (IMA; n = 11), and infrarenal but caudad to the IMA (n = 5). Extraanatomical grafts were displayed to similar advantage as collateral parietal and visceral pathways. Contrast-enhanced 3D MRA thus appears to be well suited for assessment of patients with suspected Leriche syndrome.     

Endovascular Repair of a Type III Thoracoabdominal Aortic Aneurysm in a Patient with Occlusion of Visceral Arteries

The successful endovascular repair of a type III thoracoabdominal aortic aneurysm (TAAA) with the use of a tube endograft is reported. A 56-year-old male with a 6.4-cm type III TAAA, a 4.2-cm infrarenal abdominal aortic aneurysm, and chronic renal insufficiency presented with flank pain, nausea, acute anuria, and serum creatinine of 6.1 mg/dl. Acute occlusion of the left solitary renal artery was diagnosed and emergent recanalization with percutaneus transluminal angioplasty and stenting was performed successfully, with reversal of the serum creatinine level at 1.6 mg/dl. Further imaging studies for TAAA management revealed ostial occlusion of both the celiac artery (CA) and the superior mesenteric artery (SMA) but a hypertrophic inferior mesenteric artery (IMA) providing retrograde flow to the aforementioned vessels. This rare anatomic serendipity allowed us to repair the TAAA simply by using a two-component tube endograft without fenestrations (Zenith; William Cook, Bjaeverskov, Denmark) that covered the entire length of the aneurysm, including the CA and SMA origins, since a natural arterial bypass from the IMA to the CA and SMA already existed, affording protection from gastrointestinal ischemic complications. The patient had a fast and uneventful recovery and is currently doing well 6 months after the procedure. To our knowledge, this is the first report in the English literature of successful endovascular repair of a TAAA involving visceral arteries with the simple use of a tube endograft.     

血管成像技术诊断内脏动脉瘤的临床价值

目的:探讨MSCT血管成像(MSCTA)及三维对比增强磁共振血管成像(3DDCEMRA)在腹腔内脏动脉瘤诊断和治疗中的价值。方法:回顾性分析分别经MSCTA及3DDCEMRA检查诊断的腹腔内脏动脉瘤38例患者的影像资料,采用容积重组(VR)、多平面重组(MPVR)、及最大密度投影(MIP)进行重组。结果:行MSCTA及3DMRA检查的38例患者中发现内脏动脉瘤42个,其中脾动脉瘤12个,肝动脉瘤6个,腹腔干动脉瘤8个,肠系膜上、下动脉瘤分别为6个和2个,肾动脉8个。VR、MIP、MPR可准确、清晰地显示瘤体位置、形态、范围、瘤壁、载瘤动脉和与周围血管的关系。结论:MSCTA和3DDCEMRA是简单、快速、无创、安全、可靠的血管成像技术,在诊断内脏动脉瘤方面,具有分辨力高,快速,准确,经济等优点,对腹腔内脏动脉瘤的检出具有较高的敏感度和特异度,提供的详尽信息可为尽快确定治疗方案提供依据,是诊断内脏动脉瘤的首选方法。     

急性肠系膜缺血的DSA诊断和经皮血管内治疗的临床价值探讨

目的:探讨急性肠系膜缺血的DSA诊断价值和经皮血管内治疗的临床应用价值。方法:12例临床疑诊患者,均经皮行右侧股动脉穿刺、插管,依次进行升主动脉、腹主动脉、腹腔干和肠系膜上、下动脉造影。其中8被诊断为急性肠系膜缺血,急性肠系膜上动脉栓塞4例;急性肠系膜上动脉血栓形成3例,非闭塞性肠系膜缺血1例。对4例肠系膜上动脉栓塞患者经导管注入溶栓剂(尿激霉)和血管扩张剂(罂粟碱)治疗,2例治疗后血管开通;另2例因症状缓解不明显行外科手术治疗;3例病程较长者造影后直接转外科进行手术治疗。结果:DSA诊断急性肠系膜上动脉栓塞4例。造影表现为肠系膜上动脉主干远端(中结肠动脉起始部)或分支的突然截断(截断征)或管腔内局限性充盈缺损(不完全栓塞)。急性肠系膜上动脉血栓3例,造影表现为肠系膜上动脉起始部的狭窄。1例造影表现为肠系膜上动脉分支弥漫性痉挛(腊肠征)诊断为非闭塞性肠系膜动脉缺血,手术证实为急性肠系膜静脉血栓形成。手术后1周因再次肠坏死而死亡。1例广泛血栓形成患者于造影后6h死亡。另2例肠系膜上动脉血栓患者手术后2周死亡。结论:DSA是诊断各型急性肠系膜缺血的有效手段,可以明确病变的部位和范围,为手术治疗提供定位信息。对急性肠系膜静脉血栓的诊断有一定的局限性。经导管溶栓术是治疗肠系膜动脉栓塞的有效手段。亦可作为外科手术前的辅助治疗手段,减少死亡率。     

Diagnostic value of gadolinium-enhanced 3D magnetic resonance angiography in patients with suspected hepatic arterial complications after liver transplantation

PURPOSE: To evaluate the accuracy and clinical role of gadolinium-enhanced 3D magnetic resonance angiography (MRA) in patients with suspected hepatic arterial complications after liver transplantation. MATERIALS AND METHODS: Thirty-six consecutive MRA studies were performed in 33 liver transplant recipients after transplantation. MRA image quality was assessed subjectively. Thirty-two MRA studies were retrospectively reviewed and correlated with surgery (n = 2), conventional angiography (n = 18), or clinical follow-up (n = 12). MRA findings were also correlated with those of Doppler sonography in 30 of the cases. In 20 cases, concordance between MRA and surgery or conventional angiography was evaluated for each grade of hepatic artery stenosis (normal, mild [<50%], moderate [50-75%], severe [>75%], or occluded). RESULTS: MRA image quality was degraded 13 of 36 cases (36.1%) studies. The sensitivity, specificity, and accuracy of MRA by consensus reading for more than 50% of hepatic artery stenosis or occlusion were 67%, 90%, and 81.3%, respectively. Of the 19 cases in which Doppler sonography was abnormal, MRA correctly characterized hepatic artery stenosis in 16 (84.2%). MRA also correctly identified all 5 occurrences of celiac artery stenosis. However, MRA overestimated the severity of hepatic arterial stenosis in 3 (15%) of 20 cases and underestimated 5 (25%) of 20 cases. CONCLUSION: MRA complements Doppler ultrasound to exclude significant hepatic artery stenosis. However, a substantial number of MRA studies were technically inadequate, and MRA demonstrated limited efficacy for correctly grading the severity of hepatic artery stenosis.     

Noninvasive assessment of portomesenteric venous thrombosis: current concepts and imaging strategies

Rapid, noninvasive imaging strategies, especially multidetector spiral CT and CT angiography (CTA) as well as gadolinium-enhanced MR angiography (MRA), have facilitated early diagnosis of splanchnic venous thrombosis, a potentially lethal cause of intestinal ischemia. Single breath-hold volumetric acquisitions permit superior temporal and contrast resolution while eliminating motion artifact and suppressing respiratory misregistration. Increased spatial resolution is aided by thinner slice collimation. These cross-sectional imaging techniques are becoming a preferred noninvasive alternative to conventional selective mesenteric angiography with delayed imaging for venous evaluation and should be considered the primary diagnostic modalities for evaluating patients with high clinical suspicion of nonsurgical mesenteric ischemia.     

MSCT血管成像对孤立性肠系膜上动脉夹层的诊断价值

目的:探讨MSCT血管成像诊断孤立性肠系膜上动脉夹层(SISAMD)的临床应用价值.方法:对7例急性肠缺血患者行MSCT血管成像,采用容积再现(VR)、多平面重组(MPR)、曲面重组(CPR)及最大密度投影(MIP)重组图像,由两位经验丰富的心血管影像医师评估夹层的部位和范围.结果:SISAMD与主动脉夹层CT血管成像(CTA)表现相同,CTA清晰显示撕裂内膜5例,破裂口均位于肠系膜上动脉(SMA)近心端.根据Yun分型:Ⅰ型1例,Ⅱa型3例,Ⅱb型2例,Ⅲ型1例.SMA直径增粗2例,SMA周围脂肪间隙模糊2例,局部回肠壁增厚、水肿2例,升结肠扩张、积液1例,腹腔及盆腔内少量积液2例.结论:MSCTA能清晰显示病变特征和累及范围,是孤立性肠系膜上动脉夹层首选的检查方法.     

Endovascular Treatment of Chronic Mesenteric Ischemia: Report of Five Cases

Purpose: To evaluate the midterm results of percutaneous transluminal angioplasty (PTA) and stent placement in stenotic and occluded mesenteric arteries in five consecutive patients with chronic mesenteric ischemia. Methods: Five patients with 70%–100% obliterations of all mesenteric vessels resulting in chronic mesenteric ischemia (n= 4) and as a prophylactic measure prior to abdominal aortic aneurysm repair (n= 1) underwent PTA of celiac and/or superior mesenteric artery (SMA) stenoses (n= 2), primary stenting of ostial celiac occlusions (n= 2), and secondary stenting of a SMA occlusion (n= 1; recoil after initial PTA). All patients underwent duplex ultrasonography (US) (n= 3) and/or angiography (n= 5) during a median follow-up of 21 months (range 8–42 months). Results: Clinical success was obtained in all five patients. Asymptomatic significant late restenoses (n= 3) were successfully treated with repeat PTA (n= 2) and stenting of an SMA occlusion (n= 1; celiac stent restenosis). Recurrent pain in one patient was interpreted as secondary to postsurgical abdominal adhesions. Two puncture-site complications occurred requiring local surgical treatment. Conclusions: Endovascular techniques may be attempted prior to surgery in cases of stenotic or short occlusive lesions in patients with chronic mesenteric ischemia. Surgery may still be preferred in patients with long occlusions and a low operative risk.     

Biphasic CT with mesenteric CT angiography in the evaluation of acute mesenteric ischemia: initial experience

PURPOSE: To evaluate the sensitivity and specificity of biphasic computed tomography (CT) with mesenteric CT angiography in the diagnosis of acute mesenteric ischemia (AMI). MATERIALS AND METHODS: Sixty-two patients with clinically suspected AMI underwent prospective imaging with biphasic multi-detector row CT. Mesenteric CT angiography was performed with 1.25-mm collimation starting 25 seconds after 140 mL of intravenous contrast agent was administered at a rate of 4 mL/sec, followed by portal venous phase imaging with 5-mm collimation and a 60-70-second delay. CT angiograms were reconstructed with multiplanar (including transverse), maximum intensity projection, and volume-rendered techniques. All scans were evaluated prospectively by two independent radiologists for CT evidence of ischemia. AMI was confirmed with surgical or pathologic proof in 25 of 26 patients. In one patient, AMI was confirmed with clinical findings and serial CT examinations. In patients with AMI, sensitivity and specificity of each CT sign were calculated retrospectively by using patients who did not have intestinal ischemia as a control group. CT criteria that optimized sensitivity and specificity for the diagnosis of AMI were then developed. RESULTS: AMI was diagnosed in 26 patients. The CT angiogram depicted arterial disease in eight patients and altered care in five. A finding of any one of pneumatosis intestinalis, venous gas, superior mesenteric artery occlusion, celiac and inferior mesenteric artery occlusion with distal SMA disease, or arterial embolism was 100% specific but only 73% sensitive. Alternatively, a finding of bowel wall thickening in addition to focal lack of bowel wall enhancement, solid organ infarction, or venous thrombosis was 50% sensitive and 94% specific. By using either of these criteria for the diagnosis, a sensitivity of 96% and a specificity of 94% can be achieved. CONCLUSION: Biphasic CT with mesenteric CT angiography is effective in the diagnosis of AMI.     

Endovascular Pressure Measurements to Assess the Functional Severity of Mesenteric Arterial Stenoses

PurposeTo assess the ability of pressure measurements to discriminate clinically significant celiac artery (CA) or superior mesenteric artery (SMA) stenosis in patients with suspected chronic mesenteric ischemia (CMI).Materials and MethodsSingle-center, retrospective cohort study of 41 intra-arterial pressure measurements during mesenteric angiography with intended revascularization, performed in 37 patients (mean age 67.7 ± 10.8 years, 62% female) between April 2015 and May 2017. Simultaneous prestenotic and poststenotic pressure measurements had been obtained before and after intra-arterial administration of nitroglycerin. Revascularization was performed in 38 of 41 procedures. Definitive diagnosis of CMI was defined as patient-reported symptom relief or improvement after successful revascularization.ResultsPressure gradients obtained after vasodilator administration were significantly higher in CAs and SMAs with ≥50% stenosis. Pressure ratios (pressure distal [Pd]/pressure aorta [Pa]) obtained after vasodilator administration were significantly higher in CAs with ≥50% stenosis. Subgroup analysis of 22 patients with a ≥50% stenosis of either CA or SMA showed significantly higher pressure gradients and Pd/Pa ratios after vasodilator administration in CMI patients (median pressure gradient: CMI [interquartile ratio] 36 [21-40] mm Hg versus no-CMI 20 [9-21] mm Hg, P = 0.041; Pd/Pa: CMI 0.703 [0.598-0.769] versus no-CMI 0.827 [0.818-0.906], P = .009). A ≤0.8 Pd/Pa cutoff value after administration of a vasodilator best identified a clinically relevant stenosis, with 86% sensitivity and 83% specificity. Complications related to the pressure measurements were not observed.ConclusionsIntra-arterial pressure measurements are feasible and safe. Low Pd/Pa ratios were associated with clinically relevant CA or SMA stenosis.     

Case report: percutaneous transluminal angioplasty of the inferior mesenteric artery in the treatment of chronic mesenteric ischaemia.

Percutaneous transluminal angioplasty (PTA) of the superior mesenteric artery (SMA) and coeliac axis (CA) is a well recognized form of treatment for patients with chronic intestinal ischaemia and carries a low morbidity and mortality. We report a case where PTA of the inferior mesenteric artery in the presence of occluded SMA and CA proved both feasible and highly effective in abolishing the patient's symptoms.