The Gastric Bypass for Failed Bariatric Surgical Procedures

Background: Revision of failed bariatric surgical procedures is a significant challenge for every bariatric surgeon. Methods: Evaluated are surgical difficulties, management problems and weight loss in patients with distal gastric bypass as a revisionary procedure. Eighty patients were followed up to 3 years; four were lost to follow-up. Mean age was 43; mean prebariatric surgery weight 134 kg; height 1.65 meters; body mass index 40.1; ideal body weight 62.7 kg; excess weight 70.5 kg; per cent excess weight 214%. A 250 cm stomach-to-ileocecal valve segment of small bowel was used, and the biopancreatic secretions were brought into the terminal ileum 100 cm from the ileocecal valve. Mean pouch size was 63 cc; length of hospital stay 5 days; operative blood loss 616 cc; operative time 130 min. Results: Intraoperative complications included three splenic injuries (without splenectomy). Early complications included one deep vein thrombosis, two marginal ulcers, one GI hemorrhage, one wound dehiscence, one pouch outlet obstruction and one pancreatitis. Late complications included: one death from protein malnutrition/ARDS; 21 hypoproteinemia; six protein malnutrition, and of these, three had hyperalimentation; three cholecystitis; 27 anemia; 22 incisional hernia; two staple-line disruption (reoperated); 26 low serum iron; 11 prolonged (> 6 months) diarrhea; three prolonged frequent vomiting; and two unrelated deaths (chronic myelogenous leukemia and amyotrophic lateral sclerosis). Mean excess weight loss was 83% at 12 months; 89% at 24 months; and 94% at 36 months. Conclusion: The distal gastric bypass is fraught with the operative and immediate post-operative complications experienced in any revisionary bariatric surgery. Distal gastric bypass is very effective in producing long-term weight loss. Nutritional problems are common but usually easily corrected. The most serious nutritional complication is protein malnutrition, which must be identified and corrected early. Success of this procedure is dependent upon patient compliance with proper nutrition and supplements, and regular office follow-up with monitoring of laboratory data. Patients who are noncompliant are at significant risk for complications.     

Triiodothyronine (T3) and Cardiovascular Therapeutics: A Review

Hypothyroidism is associated with an abnormal hemodynamic state characterized by decreased heart rate, stroke volume, output, and contractility, and increased systemic vascular resistance. Since cardiopulmonary bypass (CPB) and surgical stress can induce profound decreases in triiodothyronine (T3) levels, the hemodynamic consequences of "stress-induced" hypothyroidism and T3 repletion are of increasing clinical interest. Available data generally support the likelihood of a beneficial effect associated with T3 replacement in brain-dead organ donors and in cases of low cardiac output following CPB. Although hypotheses have been advanced to account for these salutary effects, the mechanism by which T3 may augment hemodynamic performance has not been precisely defined, particularly in the acute setting. Although additional research is needed to clarify these and other issues, preliminary findings with T3 replacement indicate that such investigation is warranted.     

Revisional Surgery for Severe Obesity with Fascia Banded Stoma Roux-en-Y Gastric Bypass

The fascia banded stoma Roux-en-Y gastric bypass (RYGBP) has been effective both as a primary and revision operation for severe obesity or failure of another operation. Since May 1984, 361 primary and 100 revisional fascia banded RYGBP operations have been reported. Weight loss achieved a mean body mass index of 30 for primary and 31 for revision patients at most recent follow-up of 3-6 years (mean 4.3 years) postoperatively. Mean overweight was 28% for primary, and 34% for revision patients. Eighty percent of primary and 79% of revision patients were within 50% of ideal weight. Revision rates for these patients were 0 for primary and 1% for revision patients. Operative mortality was 0 for primary and 1% for revision patients. Since morbidity and mortality, although low, are higher for revision than primary surgery, it is important to use an effective primary operation.     

The Effect of Gastric Bypass on Cholesterol,HDL, and the Risk of Coronary Heart Disease

A review of 150 charts revealed that 36 patients had pre-operative serum cholesterol greater than 200 mg% prior to Roux-Y gastric bypass. The average pre-operative weight was 266 lb (121 kg) and at 1 year post-operative 166 lb (75 kg), or 100 lb (45 kg) lost (77% excess weight loss). We compared the following pre- and post- operative data and found that: (1) cholesterol was decreased by 24% and triglycerides decreased by 40%; (2) post-operative cholesterol/HDL-C ratio of 3.31 put our patients in the half of average risk category for a clinical pathological coronary event according to the SmithKline Beecham Laboratories risk ratio chart. We conclude that Roux-Y gastric bypass and its ability to produce a significant weight loss and markedly affect cholesterol and triglyceride metabolism will also reduce a patient's risk of myocardial infarction.     

高血压病史对体外循环冠脉搭桥术后早期预后的影响

目的 :了解高血压病史对体外循环下冠脉搭桥术后早期预后的影响。方法 :对高血压和非高血压行体外循环下冠脉搭桥术年龄大于60岁的冠心病患者65例术前和术后早期的临床资料进行分析。结果 :与非高血压患者相比 ,患高血压的病人冠脉搭桥术后心律失常的发生率增高 ,术后30min动脉氧分压与吸入氧浓度 (PaO2/FiO2)比值明显低下 ,机械通气时间明显延长 ,术后24h内胸腔引流量明显增加 ,术后大剂量多巴胺 (>10μg·kg-1·min -1)应用率及重症监护时间无显著性差异。结论 :高血压病史使患者冠脉搭桥术后早期肺功能下降、心律失常发生率增高、出血倾向增加 ,提示维持高血压患者围手术期血压的正常有利于改善患者预后     

非体外循环下小儿腔肺吻合术疗效分析

为总结体外循环与非体外循环的两组病例行双向腔肺吻合(M．Glenn)术后的转归，以客观评价小儿施行非体外循环腔肺吻合术的可行性，将2000年5月--2002年11月行单纯M．Glenn术的32例患儿(年龄0．33--ll岁，体重6—32kg)分为两组，A组(n＝16)为体外循环组，B组(n＝16)为非体外循环组。所有病例监测术后1、6、12、24、48h氧合指数(OI)；测定人ICU即刻(T1)、呼吸机撤离前、后(T2和T3)3个时间点的中心静脉压(CVP)、跨肺压(TPG)、跨脑压(TCP)；记录两组病例手术时间(OT)、术后并发症、术后12h用血球量、呼吸机使用时间(VT)、ICU滞留时间(IT)以及住院费用。结果显示，B组术后OI均高于A组，尤其在术后lh和6h，OI分别为A组的1．4倍和1．3倍，差异有非常显著性(P＜0．01)。尽管撤机前B组CVP为A组的1．3倍(P＜0．05)，TCP明显低于A组，但撤机后两组差异无显著性。两组VT、IT差异虽无显著性(P＞0．05)，但B组术后12h用血球量、并发症明显降低，住院开支亦较A组节省了约30％(P＜0．05)。提示非体外循环技术应用于小儿双向腔肺吻合术是可行且有利的。     

Effects of new polymer-coated extracorporeal circuits on biocompatibility during cardiopulmonary bypass

An inflammatory response due to bioincompatibility of extracorporeal circuits is a major clinical issue during cardiopulmonary bypass (CPB). By using a swine model, we determined whether new polymer-coated circuits, the blood-contacting surfaces of which are coated with poly(2-methoxyethylacrylate) (PMEA), would reduce the inflammatory response during CPB. Plasma bradykinin levels and the percentages of CD35-positive monocytes in PMEA-coated circuits were significantly lower than those in uncoated circuits during CPB. The amount of proteins adsorbed on the PMEA-coated circuits was significantly lower than that on the uncoated circuits (0.30 microg/cm2 versus 3.42 microg/ cm2). Almost no IgG, IgM, or C3c/d was detected in proteins adsorbed on the PMEA-coated circuits although these proteins were clearly detected in proteins adsorbed on the uncoated circuits. We concluded that PMEA coating could reduce complement activation during CPB by suppressing the adsorption of IgG and IgM, which activate C3 via the classical pathway, on the surface of the circuits.     

Successful pregnancy after coronary artery bypass grafting for Kawasaki disease

Abstract A 13-year-old girl with a history of Kawasaki disease underwent coronary artery bypass grafting because of angina pectoris due to a giant coronary artery aneurysm on the left main trunk artery. Nine years after the operation, the patient had an uneventful pregnancy followed by a normal vaginal delivery. This is the first case of a successful pregnancy after coronary artery bypass grafting for Kawasaki coronary artery disease.     

Experimental Evidence of Cerebral Injury from Profound Hypothermia During Cardiopulmonary Bypass

Choreoathetosis, seizures, and impaired mental development continue to occur in children undergoing cardiopulmonary bypass (CPB) and profound hypothermia with or without circulatory arrest. Although there is some evidence that the hypothermia itself may be causing these neurologic problems, skepticism remains because of lack of evidence from experimental studies simulating the clinical setting. In this experimental study, we examined the effect of profound and moderate hypothermia on the brain while maintaining normal flow rates during CPB. Ten adult mongrel dogs equally divided into two groups were anesthetized and subjected to CPB and varying levels of hypothermia (group 1, ≤15°C; group 2, ≤32°C). Both groups were kept at the desired temperature for 1 hour prior to rewarming and discontinuation of CPB. The dogs were euthanized 4–6 weeks later and neuropathologic studies were performed. The mean CPB flow rates during cooling and at the desired rectal temperature were comparable in both groups: group 1, 108 ± 10 ml/kg/min versus 106 ± 7 ml/kg/min in group 2 (p= NS) and 95 ± 12 ml/kg/min in group 1 versus 101 ± 5 ml/kg/min in group 2 (p= NS). Because of the difference in temperature between the two groups, the mean cooling time (onset of CPB to desired rectal temperature) was longer in group 1 (70 ± 14 minutes) than in group 2 (28 ± 11 minutes, p= 0.007). Hence, the total mean CPB time was also longer in group 1 (198 ± 25 minutes) than in group 2 (143 ± 13 minutes, p= 0.002). The lowest mean blood and rectal temperature achieved in group 1 were 11 ± .9°C and 12 ± 1°C versus 29 ± .4°C (p < 0.001) and 30 ± .6°C (p= 0.001), respectively, in group 2 (p= 0.001). Neuronal loss and degeneration was noted in all dogs in group 1 ranging from 2 to 8 cells per 1000 cells counted compared to none in group 2 (p= 0.05). These lesions occurred in both the basal ganglia and the cortex, although they were more marked in the caudate when compared to the cortex and cerebellum. Both in the cortex and in the caudate, neuronal loss was more marked around the capillaries. We conclude that the use of profound hypothermia of ≤15°C and maintenance of normal flow rates during cooling at this temperature for 1 hour produces neuronal loss and degeneration in the brain. These lesions being more marked around capillaries points to the vulnerability of the neurons, probably because of their high lipid content to injury from the cold perfusate.     

The pharmacokinetics of anesthetic drugs and adjuvants during cardiopulmonary bypass

The institution of cardiopulmonary bypass during cardiac surgery has profound effects on the plasma concentration of drugs and thus their therapeutic effectiveness. These changes occur through acute hemodilution, altered plasma protein binding, hypotension, as well as the use of hypothermia and heparin administration. Isolation of the lungs from the circulation and the possible sequestration of drugs in the bypass circuit also affect drug plasma concentrations on bypass. The individual characteristics of the drug in question are also important in determining the final plasma concentration: Lipid soluble drugs with a high volume of distribution may be more readily taken up by bypass equipment, but the initial fall in concentration at the start of cardiopulmonary bypass may be more readily counteracted by back diffusion into plasma, if large tissue stores have accumulated. The extent of the drug's plasma protein binding is of importance as the effective free fraction in plasma for highly bound drugs will be sensitive to changes in plasma protein binding brought on by factors such as hemodilution, heparin administration as well as alpha, acid-glycoprotein binding. Clearly the fate of drugs administered before or on bypass is complex and can only be accurately determined by specific studies evaluating drug plasma concentrations. This review updates the available data on anesthetics and drugs used during cardiac surgery in order that anesthetists may predict better the likely effect of drugs administered before or during cardiopulmonary bypass.