Acute Mesenteric Ischemia: The Challenge of Gastroenterology

Intestinal ischemia has been classified into three major categories based on its clinical features, namely, acute mesenteric ischemia (AMI), chronic mesenteric ischemia (intestinal angina), and colonic ischemia (ischemic colitis). Acute mesenteric ischemia is not an isolated clinical entity, but a complex of diseases, including acute mesenteric arterial embolus and thrombus, mesenteric venous thrombus, and nonocclusive mesenteric ischemia (NOMI). These diseases have common clinical features caused by impaired blood perfusion to the intestine, bacterial translocation, and systemic inflammatory response syndrome. Reperfusion injury, which exacerbates the ischemic damage of the intestinal microcirculation, is another important feature of AMI. There is substantial evidence that the mortality associated with AMI varies according to its cause. Nonocclusive mesenteric ischemia is the most lethal form of AMI because of the poor understanding of its pathophysiology and its mild and nonspecific symptoms, which often delay its diagnosis. Mesenteric venous thrombosis is much less lethal than acute thromboembolism of the superior mesenteric artery and NOMI. We present an overview of the current understanding of AMI based on reported evidence. Although AMI is still lethal and in-hospital mortality rates have remained high over the last few decades, accumulated knowledge on this condition is expected to improve its prognosis.     

Emergency Hepato-Renal Artery Bypass Using a PTFE Graft

A 51-year-old patient suffering from Buerger’s disease with bilateral lower limb amputation and Leriche syndrome presented with uncontrollable hypertension and renal failure caused by right renal artery subocclusive stenosis associated with an occluded left renal artery and atrophic kidney. He underwent a right hepato-renal bypass grafting using an externally supported polytetrafluorethylene (PTFE) graft. Renal function improved markedly and hypertension could be controlled by standard antihypertensive treatment. Normal right renal function was maintained at one-year follow-up.     

Coronary Artery Bypass Risk Prediction Using Neural Networks

Background. Neural networks are nonparametric, robust, pattern recognition techniques that can be used to model complex relationships.

Methods. The applicability of multilayer perceptron neural networks (MLP) to coronary artery bypass grafting risk prediction was assessed using The Society of Thoracic Surgeons database of 80,606 patients who underwent coronary artery bypass grafting in 1993. The results of traditional logistic regression and Bayesian analysis were compared with single-layer (no hidden layer), two-layer (one hidden layer), and three-layer (two hidden layer) MLP neural networks. These networks were trained using stochastic gradient descent with early stopping. All prediction models used the same variables and were evaluated by training on 40,480 patients and cross-validation testing on a separate group of 40,126 patients. Techniques were also developed to calculate effective odds ratios for MLP networks and to generate confidence intervals for MLP risk predictions using an auxiliary “confidence MLP.”

Results. Receiver operating characteristic curve areas for predicting mortality were approximately 76% for all classifiers, including neural networks. Calibration (accuracy of posterior probability prediction) was slightly better with a two-member committee classifier that averaged the outputs of a MLP network and a logistic regression model. Unlike the individual methods, the committee classifier did not overestimate or underestimate risk for high-risk patients.

Conclusions. A committee classifier combining the best neural network and logistic regression provided the best model calibration, but the receiver operating characteristic curve area was only 76% irrespective of which predictive model was used.     

Superior Mesenteric Artery Syndrome After Roux-en-Y Gastric Bypass

Background and Objectives:

As bariatric surgery becomes more widespread, atypical complications will be seen with more frequency. In this case series, we report on 3 cases of superior mesenteric artery syndrome after gastric bypass and the laparoscopic treatment.

Methods:

This is a case series of 3 patients who presented with the persistent postprandial symptoms of pain and nausea after gastric bypass, and through an extensive workup were eventually diagnosed with superior mesenteric artery syndrome. All 3 patients had dramatic weight loss after laparoscopic Roux-en-y gastric bypasses. Gastric remnant distention was not a consistent finding, but persistent postprandial nausea, epigastric pain, and computed tomographic findings of a narrowed angle between the superior mesenteric artery and the aorta were consistently found. Two patients were treated with a laparoscopic gastroduodenal jejunostomy anastomosis, and one patient had a duodenojejunostomy, all with resolution of their symptoms.

Results:

A laparoscopic gastroduodenal (or duodeno-) jejunal bypass was performed in each case, which resolved the obstruction caused by the superior mesenteric artery syndrome.

Conclusions:

Superior mesenteric artery syndrome can be caused by the dramatic weight loss induced by a gastric bypass. This post weight loss surgery phenomenon may be far more prevalent and underdiagnosed than reported, and should be considered in all patients with greater than average weight loss at one year and who have persistent postprandial nausea and epigastric pain. This can be successfully treated by bypassing the obstruction, while maintaining the weight loss induced by the Roux-en-y gastric bypass.     

Surgery for Advanced Gastric Cancer After Coronary Artery Bypass Grafting Using the Right Gastroepiploic Artery: Report of a Case

Ischemic heart disorders are often treated by coronary artery bypass grafting (CABG) using the right gastroepiploic artery (RGEA). We report the case of a 57-year-old man with a history of CABG using the RGEA, who underwent D2 radical total gastrectomy followed by Roux-en-Y anastomosis, with successful dissection of the #6 lymph nodes, while preserving the RGEA. The patient had a 9-month history of gastric cancer, during which time the Maruyama Vaccine (Specific Substance Maruyama, or SSM) was given as alternative therapy. This case report serves to demonstrate that radical gastrectomy can be safely performed after CABG using the RGEA, and that gastric cancer will progress in spite of SSM therapy.     

自体桡动脉在不停跳冠状动脉旁路移植术中的应用

目的探讨自体桡动脉（radial artery,RA）在不停跳冠状动脉旁路移植术（off-pump coronary artery bypass graft,OPCABG）中应用的效果及安全性。方法回顾性分析我院2009年10月～2012年10月375例应用自体桡动脉（radialartery,RA）进行OPCABG的临床资料,对老年组（年龄≥60岁,n=184）及非老年组（年龄〈60岁,n=191）临床结果进行比较。结果 375例平均搭桥（3.0±0.7）支,共使用392支RA,其中右冠状动脉系统307支,前降支系统37支,回旋支系统48支。术后RA移植物相关心电图改变发生15例,无围手术期心肌梗死发生,无RA取材并发症。住院死亡率老年组为1.1%（2/184）,非老年组为1.0%（2/191）,2组比较无统计学差异（χ2=0.000,P=1.000）;主动脉球囊反搏（intra-aorticballoon pump,IABP）使用率老年组为7.6%（14/184）,非老年组为6.3%（12/191）,2组比较无统计学差异（χ2=0.255,P=0.613）;老年组住院时间（21.8±9.3）d,与非老年组（21.8±8.6）d无统计学差异（t=0.000,P=1.000）;老年组移植血管数（3.1±0.7）支,与非老年组（3.1±0.7）支无统计学差异（t=0.000,P=1.000）。273例随访3～36个月,（16.8±10.0）月,死亡5例,均为非心脏源性;23例术后残留心绞痛症状,均无心电图及影像学证据显示与RA移植物有关。结论自体RA在OPCABG中使用安全有效,有很好的近期临床效果,老年患者和非老年患者临床效果并无显著性差异。     

桡动脉在冠状动脉旁路移植术中的应用

桡动脉（RA）作为冠状动脉旁路移植术（cABG）的移植血管已广泛应用，但在其获取、手部侧枝循环的评估、抗痉挛措施、靶血管选择、以及近端吻合口等方面尚未统一的认识。一般认为RA应当连同周围的伴行静脉血管一起获取并且优先用于严重狭窄（〉70％）的冠状动脉。RA近端可以吻合于升主动脉，或者与左侧或右侧乳内动脉一起构成复合移植血管。RA作为移植血管的通畅率主要取决于靶血管狭窄的严重程度和靶血管的位置，而不是取决于近端吻合于主动脉或是乳内动脉。尽管缺乏实验证据，许多研究者提倡预防性抗痉挛治疗。在全动脉化冠状动脉旁路移植的患者中应用RA取代右侧乳内动脉作为第二选动脉移植血管具有优势。     

Minimally Invasive Axillary– Coronary Artery Bypass

Axillary artery-to-coronary artery bypass using reversed saphenous vein provides a simple method of applying the minimally invasive coronary bypass grafting procedure when the internal thoracic artery is not an adequate conduit. Although this may allow extended use of the minimally invasive coronary bypass procedure, the long-term patency of this technique is unknown.     

Thrombotic obstruction of a reinforced ringed expanded polytetrafluoroethylene graft caused by formation of a pseudoaneurysm at a nonanastomotic site: Report of a case

We report herein the case of a 72-year-old man in whom a nonanastomotic pseudoaneurysm arose from a reinforced ringed expanded polytetrafluoroethylene (EPTFE) graft (Gore-Tex, Flagstaff, AZ, USA) following an axillobifemoral bypass. The pseudoaneurysm developed 2 years after graft insertion and induced graft thrombosis. The development of the pseudoaneurysm can be attributed to the fact that his axillobifemoral bypass graft was so short it deformed the proximal anastomosis, and the graft was subcutaneously tunneled onto the major pectoral muscle. These technical errors placed the graft under too much tension in the longitudinal direction, which resulted in graft disruption and pseudoaneurysmal formation, followed by thrombosis of the axillary artery. Moreover, the possibility of direct trauma at the time of insertion cannot be substantiated. Although the very poor compliance and design of the externally supported ring could not tolerate stretch deformity in the Gore-Tex graft, only one other case of a nonanastomotic pseudoaneurysm has ever been reported.     

Emergency Pedal Artery Bypass Grafting

OBJECTIVES: To determine the value of emergency pedal artery bypass. MATERIAL AND METHODS: Data were drawn from a prospective vascular database. Inclusion criteria were: acute onset of critical forefoot ischemia, emergency surgery, no pre-operative angiographic imaging of the pedal vasculature and attempted revascularisation of a pedal vessel. Follow-up was obtained from outpatient records. The grafts were considered patent if a pedal pulse was palpable. RESULTS: Eight out of 208 pedal vascular procedures performed between January 1996 and June 2002 were entered into the study. This cohort consisted of 3 women and 5 men (age 23-85 years, median 71). Operations were performed because of thrombo-embolic occlusion of the tibial vasculature (5 patients), severe tibial embolism following a percutaneous angioplasty of the superficial femoral artery, trash foot following aortic reconstruction and acute occlusion of tibial run-off vessels following a crural reconstruction. Two patients suffered an early graft occlusion, one of them resulting in major amputation. At a median follow up of 17 months (10-52 months) the remaining 6 grafts were patent. CONCLUSIONS: If catheter directed methods (local lysis, aspiration embolectomy) or surgical procedures (embolectomy, tibial bypass) fail to treat critical foot ischemia, pedal probatorial dissection and pedal bypass is worthwhile.     

Coronary Artery Bypass Grafting After a Bilateral Lung Volume Reduction Operation

A 67-year-old man underwent coronary artery bypass grafting 3 months after a bilateral lung volume reduction operation for end-stage pulmonary emphysema. The principles of anesthetic management we have developed for use during volume reduction operations were applied with success in this individual and are described in detail. With the increasing application of this intervention as an alternative to lung transplantation, we anticipate further experience in the operative management of associated conditions after lung volume reduction operations.     

心理干预对冠状动脉旁路移植术病人术前焦虑和心肌缺血的影响

目的：探讨心理干预对冠状动脉旁路移植术病人术前焦虑和心肌缺血的影响。方法：将41例接受冠状动脉旁路移植术的冠心病病人随机分为观察组（21例）和对照组（20例），对照组接受一般心理干预，观察组接受依据准确期待论制定的干预措施。测定并比较两组病人术前焦虑值、心率、血压和心肌缺血发生情况。结果：心理干预后观察组术前各阶段心率、血压、焦虑值均显著低于对照组（P＜0．05，P＜0．01），待手术期观察组心肌缺血事件亦显著少于对照组（P＜0．05）。结论：心理干预可缓解冠状动脉旁路移植术病人术前焦虑和减少术前心肌缺血事件的发生。     

冠状动脉旁路移植术后围术期心肌缺血

目的　　探讨冠状动脉旁路移植术 (CABG)术后出现围术期心肌缺血 (PMI)的相关危险因素及其处理措施。　方法　回顾性总结 2 6 80例 CABG患者的临床资料 ,并根据术后是否发生 PMI将其分为 PMI组 (30例 )和非PMI组 (2 6 5 0例 ) ,分析 CABG后出现 PMI的危险因素。　结果　 PMI组中 11例进行急诊再血管化 ,其余行主动脉内球囊反搏 (IABP)或药物治疗 ;院内死亡 7例 ,死亡率为 2 3.3%。心绞痛症状缓解 2 2例 ,心电图完全或部分复原 9例 ,残留心肌梗死改变 14例。非 PMI组院内死亡 5 8例 ,死亡率为 2 .2 %。两组死亡率之间比较差别具有显著性意义(χ2 =5 6 .0 4 ,P=0 .0 0 1)。多因素分析表明 ,术前无心肌梗死史、冠状动脉弥漫性病变和术中内膜剥脱为相关危险因素。结论　 PMI是 CABG术后一种比较危险的并发症 ,严重者可危及生命 ,及早诊断和适当的治疗尤为重要 ,对于因旁路血管堵塞造成的 PMI,急诊再次血管移植是挽救患者生命的必要措施。     

桡动脉桥血管应用于冠状动脉旁路移植术的围术期疗效分析

摘要：目的探讨桡动脉作为第二动脉桥血管对冠状动脉旁路移植术围术期手术疗效的影响。方法回顾性分析2011年8月至2012年4月沈阳军区总医院连续接受非体外循环冠状动脉旁路移植术175例患者的临床资料,175例患者随机分为两组,组1：75例,男49例,女26例;年龄（56．8±8．2）岁;应用桡动脉作为桥血管材料;组2：100例,男66例,女34例;年龄（57．7±8．1）岁;使用大隐静脉作为桥血管材料,不用桡动脉作为桥血管材料;两组患者左乳内动脉使用率均为100％。比较两组患者围术期心血管事件发生率及其它临床参数。结果所有患者术后30d内均存活。两组患者手术时间、术后24h胸腔引流量、术后住院时间比较差异无统计学意义（P〉0．05）。术后重症监护时间、机械辅助通气时间虽然两组间差异无统计学意义,但组1较组2有减少趋势。术后因心功能不佳需较长时间心血管活性药物支持方面,两组间差异虽无统计学意义,但组2患者的比率高于组1[16％（16／100）VS．12％（9／75）]。组1患者术后无新发心肌缺血和因血流动力学不稳定而行主动脉内球囊反搏（IABP）辅助;组2有3例患者出现新发心肌缺血,新增2例IABP辅助。结论桡动脉作为桥血管取代部分大隐静脉,不仅并未增加围术期心血管事件的风险,反而在一定程度上有利于患者的恢复。桡动脉可更加广泛地应用于冠状动脉旁路移植术。     

The Clinical Significance of Performing Preoperative Angiography of the Internal Thoracic Artery in Coronary Artery Bypass Surgery

(Received for publication on Nov. 25, 1996; accepted on July 8, 1997)     

急性肠系膜上动脉栓塞的诊治探讨

目的:探讨急性肠系膜上动脉栓塞的发病原因、早期诊断和治疗.方法:对17例患者的临床资料进行回顾性分析.结果:17例患者都实施手术治疗,痊愈8例,死亡9例.结论:Bergan三联征、DSA可作为早期诊断的标准,而及时正确施治是提高治愈率的关键.     

双侧乳内动脉Y型桥冠状动脉旁路移植术中远期临床疗效分析

目的评价双侧乳内动脉Y型桥冠状动脉旁路移植术的中远期疗效,分析影响疗效的因素,提高手术的成功率。方法回顾性分析2000年1月至2004年5月165例冠心病患者术前、术后及中远期随访的临床资料,比较心功能变化。采用logistic回归分析影响死亡的危险因素。结果全组共移植血管561支,平均每例移植血管3．4支。围术期无死亡,术后发生并发症16例,包括心绞痛复发、心肌梗死、低心排血量、伤口愈合不良等,均经相应的处理治愈出院。随访160例（97％）,随访时间5．6±1．2年。随访期间死亡23例,其中心源性死亡10例,包括再次心肌梗死3例,心力衰竭4例,恶性心律失常3例;非心源性死亡13例,包括胃肠道出血4例,癌症3例,不明原因6例。发生心脏相关并发症25例,包括心绞痛复发18例,心肌梗死4例,再次手术包括冠状动脉介入治疗和冠状动脉旁路移植3例。术后左心室射血分数较术前明显提高（54％±6％vs．43％±12％）;术后1年,3年,5年实际生存率分别为98．2％±0．3％,96．2％±0．5％和90．5％±1.9％,免于心脏相关事件发生率分别为95．5％±1．2％,91．3％±2．1％和86．6％±1．5％。单因素分析显示：年龄〉65岁、糖尿病、射血分数〈30％、心功能分级（NYHA）Ⅲ／Ⅳ级和低心排血量需主动脉内球囊反搏治疗是术后发生主要心血管事件的危险因素。logistic多因素分析结果显示：年龄〉65岁（OR=11．6）、糖尿病（OR=21．4）、射血分数〈30％（OR=37．5）和心功能分级（NYHA）Ⅲ／Ⅳ级（OR=40．2）是预示晚期死亡的危险因素。结论双侧乳内动脉Y型桥冠状动脉旁路移植术能减少术后心血管相关事件的发生率,提高远期生存率。心功能分级Ⅲ／Ⅳ级、射血分数〈30％、糖尿病、年龄〉65岁是影响远期疗效的独立危险因素。