Cardiopulmonary bypass recommendations in adults: the northern New England experience

Using a regional cardiopulmonary bypass (CPB) registry, we compared the practice of CPB at eight northern New England institutions to recently published recommendations. We examined CPB practice among 3597 adult patients undergoing isolated coronary artery bypass grafting surgery from January 2004 to June 2005. Registry variables were used to compare regional CPB practice to recommendations on topics of neurologic protection (pH management, avoidance of hyperthermia, minimizing return of pericardial suction blood, aortic assessment, arterial line filtration), maintenance of euglycemia, reduction of hemodilution, and attenuation of the inflammatory response. We report overall regional practice (regional minimum, maximum). All centers used alpha-stat pH management and arterial line filters. Avoidance of hyperthermia (temperature < 37degrees C) was achieved during 23.4% of procedures (regional minimum, 1.5%; maximum, 83.2%). Minimizing return of pericardial suction blood was achieved in 23.7% of cases (0.7%, 93.6%). Aortic assessment was performed during 45.7% of procedures (1.3%, 98.9%). Maintenance of euglycemia (< 200 mg/dL) was accomplished in 82.7% (57.1%, 97.9%) of cases. Hemodilution (hematocrit < 23% on CPB) was lower for men 32.4% (20.6%, 52.3%) than women 77.9% (64.7% 88.9%). Men were less likely to receive red blood cell transfusions in the operating room (11.0%; 1.8%, 20.9%) than women (54.6%; 30.1%, 70.6%). In an effort to attenuate the inflammatory response, surface coated circuits were used in 83.3% of procedures (8.8%, 100%). During this time, gaps existed between regional CPB practice and recently published recommendations. We continue to prospectively measure CPB practice relating to these recommendations to monitor and improve the care provided to our patients.     

Long-term evaluation of EC-IC bypass patency

Summary The EC-IC Bypass Study Group could not detect any benefit from surgery compared to medical management in the prevention of stroke in 1985 [15]. During the past years surgical revascularization was re-evaluated and considered as an appropriate treatment for a small subgroup of patients with recurrent focal cerebral ischaemia and impaired haemodynamics. This retrospective study examines the long-term benefit and patency rate of bypass.We present a follow-up of 5.6 years of 47 patients, all of whom underwent byupass surgery after 1985. Forty patients suffered recurring transient ischaemic attacks due to uni- or bilateral internal carotid artery occlusion. Examination included neurologic status, TCD with CO₂ or Diamox challenge, angiography, CT and SPECT scans.Neurological improvement was seen in 23% of patients with better results after early surgery, a worsening in 22% suffering further ischaemic events on a postoperative average of 2.8 years. Patency rate for vein graft material was 50%, for the STA-MCA procedure 91%. Occlusion of the vein graft occurred on an average after 1.4 years, other anastomosis after 2.7 years.We conclude that only few patients derived long-term benefit from EC-IC bypasses. Functioning of the bypass worsens over time, suggesting a role for surgery predominantly in the first year of ischaemic events due to insufficient collateral supply. Actual indications for bypass surgery may be patients with failure of maximal medical therapy and progressive ischaemia and haemodynamic compromise.     

Perforated marginal ulcer after gastric bypass for obesity: a systematic review

Marginal ulcers are a recognized complication of gastric bypass procedures for obesity. Perforated marginal ulcer (PMU) is a life-threatening complication of marginal ulcers. We performed a systematic review to understand the presentation, management, and outcomes of PMUs. PubMed, Google Scholar, and Embase databases were searched to identify all studies on PMUs after gastric bypass procedures. A total of 610 patients were identified from 26 articles. The mean age was 39.8±2.59 years, and females represented most of the cohort (67%). The mean body mass index was 43.2±5.67 kg/m². Most of the patients had undergone a Roux-en-Y gastric bypass (98%). The time gap between the primary bariatric surgery and the diagnosis of PMU was 27.5±8.56 months. The most common presenting symptom was abdominal pain (99.5%) and a computed tomography scan was the diagnostic modality used in 72% of the patients. Only 15% of patients were on prophylactic proton pump inhibitors or H2 blockers at the time of perforation, and 41% of patients were smoking at the time. Twenty-three percent of patients were on nonsteroidal anti-inflammatory drugs. Laparoscopic omental patch repair of the perforation (59%) was the most used technique; 18% of patients underwent open surgery, and 20% were managed non-surgically. Thirty-day mortality was 0.97%; it was 1.21% (n=5) and 0% (n=0) in those who were managed surgically and nonsurgically, respectively. Ulcers recurred in 5% of patients. In conclusion, PMU is a surgical emergency after gastric bypass that can result in significant morbidity and even mortality. This is the first systematic review in scientific literature characterizing this condition.     

Early results of off-pump coronary artery bypass

Objective: The purpose of this study is to compare the operative results of off-pump coronary artery bypass (OPCAB) and on-pump (conventional) coronary artery bypass (CCAB), to clarify qualitative problems and whether OPCAB is less invasive or not. Methods: OPCAB was consecutively performed in 63 patients and CCAB in 63 patients between July 1998 and December 2003. Results: The mean number of bypass grafts was 2.43 ±0.82 in the OPCAB group and 2.70±0.71 in the CCAB group (p=0.096). In-hospital mortality was 0% in the OPCAB group and 3.2% in the CCAB group. The incidence of perioperative myocardial infarction was 0% in the OPCAB group and 3.2% in the CCAB group. The incidence of postoperative major complications was significantly lower in the OPCAB group than in the CCAB group (OPCAB group=4 complications, CCAB group=13 complications). Cerebrovascular accidents occurred in 1.6% of patients in both groups. The incidence of sternal infection or mediastinitis was 0% in the OPCAB group and 3.2% in the CCAB group. The early patency rate of graft was 94.0% in the OPCAB group and 92.8% in the CCAB group, and was not significantly different (p=0.822). Conclusion: Operative mortality and major complications after surgery in OPCAB were lower than that in CCAB. The early patency rate in OPCAB was as good as that in CCAB. It is considered that OPCAB is less invasive and the quality of bypass in OPCAB is as good as that in CCAB.     

Infrageniculate thin-walled PTFE bypass: Preliminary study of 53 cases

Between May 1, 1983 and May 1, 1985, 53 patients whose mean age was 75 years, and who presented with rest pain or ischemic changes had infrageniculate insertion of femoropopliteal or femorotibial thin-walled polytetrafluoroethylene (PTFE-TW) bypasses. Occlusive atherosclerotic disease was present in all patients. Postoperative follow-up ranged from 6 to 30 months. One patient died in the immediate post-operative period whereas 15 others died later during follow-up. There was one case of prosthetic sepsis. No anastomotic aneurysms occurred. Actuarial analysis of overall patency rates in significant population samples showed that 88% and 68% of bypasses were functional at one month and two years, respectively. The overall rate of early amputation was 17%. Overall limb salvage was 67% at 30 months. In patients over 75, 85% of bypasses were patent at one year whereas life expectancy for one year in this same group of patients was 49%. Although this is a preliminary study, results obtained with this new material suggest that an average gain of 20% in patency rates can be expected compared to those recorded with standard PTFE prostheses. The PTFE-TW vascular prosthesis may be the material of first choice for the geriatric patient in order to promote early hospital discharge and return to the home environment. Even though long-term patency rates of venous grafts are better, we believe that the use of PTFE-TW prostheses in elderly patients with limited life expectancy may be preferred.     

Combined aortobifemoral and femoropopliteal bypass in the management of patients with extensive atherosclerosis

Certain patients have atherosclerosis in both aortoillac and femoropopliteal segments of the arterial tree and thus do not have a good result from reconstruction of the aortoiliac segment. No method has been developed to identify these patients and we do not know whether, by combining a femoropopliteal bypass with an aortobifemoral bypass, the results can be improved. We present a series of 153 patients with severe multilevel occlusive disease treated by simultaneous reconstruction and followed for up to 6.5 years. The cumulative patency of the femoropopliteal bypasses was 80% at four years. Functional and symptomatic improvement was excellent, and operative mortality was low when one considers the age and poor general condition of the patients.     

Unilateral iliac artery occlusive disease: A randomized multicenter trial examining direct revascularization versus crossover bypass

This randomized trial compared the patency of direct unilateral aorto- or iliofemoral prosthetic bypass with that of crossover femorofemoral or iliofemoral bypass in unilateral atheromatous occlusive disease of the iliac artery. Between May 1986 and March 1991, 143 patients were enrolled in this study (74 crossover and 69 direct revascularizations). Cardiovascular risk factors, preoperative symptoms, and atheromatous lesions were similar in both groups. Patients were followed by Duplex scanning with systolic pressure index measurements. Routine digital subtraction arteriograms were obtained postoperatively and separately, when hemodynamic anomalies developed. Mean follow-up was 22 months. One patient with direct revascularization died postoperatively. Primary patency of direct revascularizations was 89.8% at 48 months compared with 52% for crossover bypass. This difference was statistically significant. Secondary patency of direct and crossover revascularization at 48 months was 92.9% and 93.6%, respectively (not significant). Even though crossover bypasses seem attractive because of their technical simplicity and low morbidity, our results suggest that direct revascularizations are preferable in the young patient with no major operative risks, while crossover bypasses remain indicated in patients at risk.Presented at the Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, June 20–21 1991, Marseille, France.     

Methodologies,Devices, and New Surgical Concepts: Novel System for Percutaneous Cardiopulmonary Bypass

Percutaneous cardiopulmonary bypass (PCPB) has recently come to the forefront of medicine as a technique for resuscitating and supporting patients in various clinical situations. Current systems utilize small-diameter cannulas to aspirate blood under high suction into the cardiopulmonary bypass circuit. Aspiration-based systems have several disadvantages including risk of air embolism, blood hemolysis, and cavitation. Additionally, they are suboptimal for use during open-heart surgical procedures. A system with a venous cannula that employs gravity drainage has been evaluated. Once advanced into position over a guide- wire, the stylet is removed, causing the basket near the end of the cannula to expand. Blood flows into the cannula from side holes and the basket region, which prevents the vessel wall or atrium from collapsing around the catheter and impeding venous drainage. Hemodynamic, hematologic, and histologic examinations were performed on eight anesthetized mongrel dogs during 2 h of PCPB. All animals exhibited adequate tissue perfusion and right and left heart decompression. All animals were successfully weaned from PCPB and after 30 min exhibited normal myocardial function. No ischemic changes were observed in the heart, lung, kidney, or liver by light and electron microscopy. We conclude that full PCPB can be satisfactorily achieved by using a novel percutaneous venous cannula and gravity drainage     

Paracorporeal Artificial Heart in Postoperative Heart Failure

A pneumatically driven artificial heart with a tubular silicone rubber membrane and disc valves was used for functional heart replacement in the paracorporeal mode. A fluidic drive system allows adjustment of the heart rate, positive and negative pressures and systole/diastole ratio.
Since August, 1977, the artificial heart has been used in four patients with refractory postoperative heart failure not responding to volume loading, pH and electrolyte correction, catecholamines and intraaortic balloon pumping. Large cannulae were placed in the atria and great vessels. The ventricles were fixed on the chest paracorporeally. The assist system was used as a left heart bypass in one patient and as a biventricular bypass in three other patients. After 48–72 hours, the ventricular function recovered in three patients, permitting removal of the artificial heart. One patient died of cerebral complications six weeks later; the other two recovered completely and were released in good condition.
Profound postoperative heart failure can be completely reversed by the use of the paracorporeal artificial heart; the advantage of the system lies in the simplicity of its implantation and removal.     

Sequential bypass for multisegmental occlusive disease

We evaluated the effectiveness of a sequential bypass for multisegmental occlusive disease. Forty-seven multiple bypass grafts were performed on 43 patients ranging in age from 55 to 83 years (mean: 70 years). The indications for operation included incapacitating claudication in 20 limbs, resting pain in 15, and nonhealing ulcers in 12. An anatomical arterial bypass was performed on 36 limbs, consisting of an aorto-femoro-popliteal bypass in 21 limbs, a femoro-popliteal-posterior tibial bypass in 8, an ilio-femoro-popliteal bypass in 4, an ilio-femoro-posterior tibial bypass in 2, and a femoro-popliteal-plantar bypass in 1. Similarly, an extra-anatomical arterial bypass was performed on 11 limbs, consisting of an axillo-femoro-popliteal bypass in 6, a crossover femoro-femoro-popliteal bypass in 3, an axillo-femoro-posterior tibial bypass in 1, and a crossover femoro-femoro-anterior tibial bypass in 1. The follow-up period ranged from 3 to 77 months (mean: 23 months). Twelve graft failures occurred, and 2 of them required major amputations. The cumulative graft patency rate was 85% at one year and 65% at 3 years. Arterial Doppler examination revealed a mean preoperative ankle-brachial index of 0.29±0.25. The early and late mean postoperative ankle-brachial indices, however, increased to 0.97±0.19 and 0.84±0.25, respectively. Midterm results have indicated that such multiple sequential bypass grafts are effective.Presented at the 8th Congress Asian Surgical Association, Fukuoka, Japan, March 10–13, 1991     

Effect of Location and Speed of Diagnosis on Anastomotic Leak Outcomes in 3828 Gastric Bypass Cases

Introduction Leaks after Roux-en-Y gastric bypass are a major cause of mortality. This study attempts to define the relationship between the leak site, time from surgery to detection, and outcome. Methods Retrospective review of 3,828 gastric bypass procedures. Results Of the leaks (3.9% overall), 60/2,337 (2.6%) occurred after open gastric bypass, 57/1,080 (5.2%) after laparoscopic gastric bypass, and 33/411 (8.0%) after revisions. Overall leak-related mortality after Roux-en-Y gastric bypass was 0.6% (22/3,828). Mortality rate from gastrojejunostomy leaks (38 in the open gastric bypass, and 43 in the laparoscopic) was higher in the open group than the laparoscopic group (18.4 vs 2.3%, p = 0.015). Median time of detection for a gastrojejunostomy leak in the open group was longer than in the laparoscopic group (3 vs 1 days, Wilcoxon score p < 0.001). Jejunojejunostomy (JJ) leak was associated with a 40% mortality rate. Initial upper gastrointestinal series did not detect 9/10 jejunojejunostomy leaks. Median detection time was longer in the jejunojejunostomy leak group than the gastrojejunostomy leak group (4 vs 2 days, p = 0.037). Discussion Leak mortality and time of detection was higher after open gastric bypass than laparoscopic gastric bypass. GBP patients with normal upper gastrointestinal (UGI) studies may harbor leaks, especially at the JJ or excluded stomach. Normal UGI findings should not delay therapy if clinical signs suggest a leak. This paper was presented at The Society for Surgery of the Alimentary Tract, 47th Annual Meeting at Digestive Disease Week 2006, May 20–24, 2006, Los Angeles, California.     

Coronary artery bypass graft in a human immunodeficiency virus positive patient

Coronary artery bypass surgery in a Human immunodeficiency virus positive patient introduces additional risks to the surgical team. We report one such patient     

A five-to seven-year experience with externally-supported Dacron prostheses in axillofemoral and femoropopliteal bypass

We have examined the clinical results of 56 externally-supported (EXS) Dacron grafts in the axillofemoral position and 117 in the femoropopliteal position. Results have been analyzed from two perspectives: primary patency concerns only those grafts that had never occluded; extended patency refers to all open grafts including those whose continued patency is the result of thrombectomy. The 5-to 7-year life-table patency rates are: axillofemoral 8 mm and 6 mm bypass: primary 75% and extended 97%; above-knee femoropopliteal 6 mm bypass: primary 78% and extended 93%; below-knee 6 mm femoropopliteal bypass: primary 41% and extended 91%. In contrast, the results for the 5 mm grafts used for femoropopliteal bypass were inferior to the 6 mm grafts: femoropopliteal 5 mm bypasses had an above-knee primary patency rate of 44% and an extended rate of 55%, with a below-knee primary patency rate of 15% and an extended rate of 32%. Rendering the noncrimped porous Dacron prosthesis kink and compression resistant by an external support coil appears to increase its potential for successful use, especially in 8 mm axillofemoral and 6 mm femoropopliteal bypasses. Presented to the Western Vascular Society, January 1986, Laguna Niguel, California.     

浅低温体外循环冠脉搭桥患者术中氧供和氧耗变化

观察浅低温体外循环冠脉搭手术期间患者氧供和氧耗的变化特点。方法：冠脉搭桥术患者３０例,小剂量芬太尼辅以异氟醚和异丙酚维持麻醉,于麻醉后切皮瓣、开胸后体外循环前,体外循环３０分钟、６０分钟停机后２０仲,手术结束六个时点,观测氧供（ＤＯ２）、氧耗（ＶＯ２）氧摄取率（Ｏ２ＥＲ）、混合静脉血氧饱和度（ＳｖＯ２）、动脉血乳酸（ＢＬ）及血流动力学等变化。结果：和体外循环前相比,体外循环中和体外循环后除ＳｐＯ２     

体外循环与非体外循环下冠脉搭桥术患者术中血液动力学的比较

目的比较体外循环(CPB)与非CPB下冠脉搭桥术患者术中血液动力学的变化。方法同期行CPB下冠状动脉搭桥术(CABG)与非CPB下冠状动脉搭桥术(OPCAB)患者各70例,分别为CABG组和OPCAB组,分别在麻醉诱导后手术开始前(术前)和术毕用Swan-Ganz导管监测血液动力学指标。结果与术前比较,两组术毕心率(HR)、平均动脉压(MAP)、肺动脉平均压(PAMP)、肺毛细血管嵌压(PAWP)、中心静脉压(CVP)及左室作功指数(LVSWI)差异无统计学意义(P>0.05),心输出量(CO)、心脏指数(CI)均升高;OPCAB组术毕心搏指数(SVI)升高,体循环阻力指数(SVRI)、肺循环阻力指数(PVRI)降低(P<0.05),CABG组术毕SVI、SVRI、PVRI差异无统计学意义(P>0.05);与CABG组比较,OPCAB组术毕SVRI、PVRI降低(P<0.05)。结论两组患者术后心功能均得到了改善,OPCAB 组在改善心功能、降低体、肺循环阻力方面,优于CABG组。     

Transmyocardial laser revascularization in combination with coronary artery bypass: Clinical, wall motion and perfusion effects

Background. Transmyocardial laser revascularisation (TMR) is increasingly used in the management of intractable angina in the absence of graftable vessels, however it’s role in combination with coronary artery bypass remains undefined. The aim of this pilot study was to investigate the impact of the combination therapy. Methods. Patients (20) undergoing elective coronary artery bypass surgery with one or more non-graftable coronary arteries were prospectively randomized to either have bypass graft surgery alone (CABG) or bypass graft surgery and transmyocardial revascularization with a holmium — YAG laser to non-graftable areas (CABG+TMR). All patients had exercise tolerance test preoperatively and at 6 and 18 months follow-up. Stress echocardiography was performed on 17 patients 18 months following surgery. Wall motion analysis (1=normal, 2=hypokinesis, 3=akinesis, 4=dyskinesis) using the 16 segment model of the left ventricle and rest and stress perfusion analysis were performed. Results. Both groups of patients were similar in preoperative demographics and operative data. There was no perioperative mortality. There was no difference between the two groups in angina scoring at 6 and 18 months follow-up. Exercise tolerance improved by a mean of 46.8±20.0 seconds per patient in the CABG group and by 199.2±66.5 seconds per patient in the CABG+TMR group (p<0.05) and this was maintained at 18 months (157±46.3 vs 61±39.2 seconds; p<0.05). Regional wall motion score index (WMSI) (total score/number of segments) was calculated in non-revascularizable myocardium treated with TMR and compared to areas that were not lased. Although the WMSI in TMR regions is lower at each stage of dobutamine stress, this does not reach statistical significance. Conclusion. The combination of coronary artery bypass and transmyocardial laser revascularization is safe and improves exercise tolerance in patients in whom complete revascularization cannot be achieved by bypass graft surgery alone. Competition paper presented at the 48th Annual Conference of IACTS at Chennai Feb. 2002     

Off-pump coronary artery bypass grafting in patients with significant left ventricular dysfunction

Objective  Off-pump coronary artery bypass grafting (OPCAB) is known to preserve left ventricular function better than conventional coronary artery bypass grafting (CCAB). This study was carried out to investigate the safety, feasibility and efficacy of off-pump coronary artery bypass grafting in patients with significant left ventricular dysfunction. Methods  Three hundred and eighty eight consecutive patients with preoperative left ventricular ejection fraction ≤ 39% who underwent CABG between January 2001 through October 2007 were included in this retrospective study. Two hundred and eleven patients were operated by off-pump technique (group 1) and 178 patients were operated by on-pump technique (CCAB) (group 2). The postoperative outcomes were analyzed. Of these, 204 (52.57%) patients were diabetics, 355 (91.49%) patients had documented prior myocardial infarction, 316 (81.44%) patients were in canadian cardiovascular society(CCS) class III and 47 (12.11%) patients were in CCS class IV. Results  There was no significant difference in the number of grafts per patient between the two groups [group 1 3.02 ± 0.76 vs group 2 3.18 ± 0.72 (P=0.07) and the index of completeness of revascularization was comparable [1.08 ± 0.08) (OPCAB) vs 1.04 ± 0.06 (CCAB) (p=0.52)] The left internal thoracic artery was anastomosed to left anterior descending artery in 98% of patients. Operative mortality was 2.8% (6 deaths) following OPCAB and 3.93% (7 deaths) following CCAB (p=0746). Postoperative usage of IABP support was higher in CCAB group (12 patients vs 4 patients: P<0.03) and usage of moderate or higher doses of inotropic support was also higher in the conventional group (p<0.0006). More worsening of preexisting renal insufficiency was observed in CCAB group (p=0.01) and no significant difference in the incidence of atrial fibrillation was observed between the groups. Conclusions  Off-pump coronary artery bypass grafting is feasible and safe in patients with depressed left ventricular function and the postoperative morbidity was less in OPCAB group compared to on-pump group.     

心脏不停跳非体外循环冠状动脉旁路移植术的进展

近年来，随着手术器械的发展，心脏不停跳非体外循环下冠状动脉旁路移植术(OPCAB)逐渐被广泛接受和应用。与常规冠状动脉旁路移植术(CCABG)比较，OPCAB的主要优势为血液中多种炎性介质浓度明显降低，避免了体外循环(CPB)带来的全身系统性炎性损害，减少了并发症，降低了手术死亡率。特别对那些不能采用CPB或采用CPB有风险的高危患者优势更明显。CCABG的手术适应证同样适用于OPCAB，但OPCAB具有相对的禁忌证。OPCAB多采用胸骨正中切口，左前外侧切口适用于左前降支单支病变。OPCAB术后早期结果类似CCABG，但中远期结果有待进一步观察。OPCAB大多数旁路移植血管数低于CCABG，有不能完全再血管化的可能，对OPCAB是否会影响吻合的精确性和旁路血管的长期通畅率有不同意见。OPCAB的优势明确，但仍不能完全替代CCABG，手术的同时应作好CPB准备，必要时改行CCABG。     

体外循环与非体外循环下冠状动脉旁路移植术孰优孰劣

近年来冠状动脉旁路移植术有了很大的进展。采用非体外循环冠状动脉旁路移植术能避免体外循环带来的并发症,而得到越来越多的重视,但其技术难度大;传统的冠状动脉旁路移植术在体外循环的辅助下可以提供较好的血管吻合条件,仍被广泛采用。现将对两种手术方法的移植血管通畅率、死亡率、炎症反应、凝血与抗凝的影响、器官系统损伤、住院时间和费用、术式转换等方面的比较进行综述。