Lloyd D. MacLean

Surgery Decreases Long-term Mortality, Morbidity, and Health Care Use in Morbidly Obese Patients

Objective:This study tested the hypothesis that weight-reduction (bariatric) surgery reduces long-term mortality in morbidly obese patients. Background:Obesity is a significant cause of morbidity and mortality. The impact of surgically induced, long-term weight loss on this mortality is unknown. Methods:We used an observational 2-cohort study. The treatment cohort (n = 1035) included patients having undergone bariatric surgery at the McGill University Health Centre between 1986 and 2002. The control group (n = 5746) included age- and gender-matched severely obese patients who had not undergone weight-reduction surgery identified from the Quebec provincial health insurance database. Subjects with medical conditions (other then morbid obesity) at cohort-inception into the study were excluded. The cohorts were followed for a maximum of 5 years from inception. Results:The cohorts were well matched for age, gender, and duration of follow-up. Bariatric surgery resulted in significant reduction in mean percent excess weight loss (67.1%, P < 0.001). Bariatric surgery patients had significant risk reductions for developing cardiovascular, cancer, endocrine, infectious, psychiatric, and mental disorders compared with controls, with the exception of hematologic (no difference) and digestive diseases (increased rates in the bariatric cohort). The mortality rate in the bariatric surgery cohort was 0.68% compared with 6.17% in controls (relative risk 0.11, 95% confidence interval 0.04–0.27), which translates to a reduction in the relative risk of death by 89%. Conclusions:This study shows that weight-loss surgery significantly decreases overall mortality as well as the development of new health-related conditions in morbidly obese patients.

Stomal ulcer after gastric bypass

BACKGROUND Stomal ulcer is a serious complication of gastrogastric fistula following Roux-en-Y gastric bypass for obesity. STUDY DESIGN A 1-8 year continuous followup of 499 patients with gastric bypass in continuity (GB) and isolated gastric bypass (IGB) documented the incidence of fistula formation, development of stomal ulcer, stimulation of acid production within the gastric pouch, and response to treatment. RESULTS In 123 GB patients, staple line disruption occurred in 36 (29%) and stomal ulcer occurred in 20 (16%). Gastrogastric fistula with stomal ulcer was significantly lower in 376 patients who underwent IGB, (ie, 11 patients [3%]). Significantly larger amounts of acid, a lower pH, and a greater time with a pH less than 2 were found in the gastric pouches of patients who developed stomal ulcer after Roux-en-Y gastric bypass. All patients had a perforated staple line. Successful closure of the staple line significantly decreased acid production and pH in the gastric pouch when tested before and after remedial operation with healing of stomal ulcers. CONCLUSIONS Stomal ulcer after gastric bypass is the result of acid production in the bypassed stomach in the presence of a gastrogastric fistula. Separation of the gastric pouch from the main stomach decreases the incidence of fistula formation and stomal ulcer but does not eliminate it. Interposition of a well vascularized organ, the jejunum between the pouch and main stomach, is an attractive solution for patients who require remedial operations on the stomach and possibly for primary operations as well.

Iron Absorption and Therapy after Gastric Bypass

Background: Iron deficiency anemia is a common complication of gastric bypass. The authors assessed the value of taking vitamin C with oral iron in correcting deficiencies in iron stores and anemia postoperatively. Materials and Methods: Iron absorption tests were performed on 55 patients 3.2 ± 2.0 years after isolated gastric bypass to identify those at higher risk for the late development of anemia. Twenty-nine of this group agreed to a therapeutic trial of iron alone or with vitamin C over a 2-month period. All 55 patients were followed up for 27.1 ± 1.0 months following the study. Results: The iron absorption test identified patients with low iron stores, as indicated by low serum ferritin, and those with sufficient absorption surface to benefit from oral iron. The addition of vitamin C appears to enhance the therapeutic effect of iron by correcting ferritin deficits (P < 0.01) and anemia (P < 0.05). Differences in intestine length bypassed by the operation (10 vs. 100 cm) did not affect late ferritin and hemoglobin values. Conclusion: This study suggests but does not prove that the addition of vitamin C to iron therapy after gastric bypass is more effective in restoring ferritin and hemoglobin than iron alone. These results are in contrast with the outcome 22.8 months later, when ∼50% of study patients were again anemic. Closer follow-up of patients is urgently needed.

Treatment of Vitamin B12 Deficiency after Gastric Surgery for Severe Obesity

Background: Vitamin B12 deficiency after gastric surgery for obesity is due to a failure of separation of vitamin B12 from protein foodstuffs and to a failure of absorption of crystalline vitamin B12 in the presence of intrinsic factor. The purpose of this study was to determine which of four oral doses of crystalline vitamin B12 was most effective in treating vitamin B12 deficiency in 102 patients. Methods and Results: At time of entry into the study, the patients had a serum vitamin B12 < 100 pmol L −1, were 29.9 ± 21.7 months post-op, were 37 ± 8 years old and had a body mass index of 30 ± 6 kg m−2. Eight (8%) had had a vertical banded gastroplasty and 94 (92%) a gastric bypass. For the first 3 months all patients received 350 μg per day of crystalline vitamin B12 and all increased their serum vitamin B12 levels to over 100 pmol L−1. The patients were then assigned to receive for a further 3 month period one of four oral doses of crystalline vitamin B12-100 μg, 250 μg, 350 μg and 600 μg. Serum vitamin B12 levels were greater than 150 pmol L−1 after 6 months in 83.3% of patients who received 100 μg; 92.3% of patients who received 250 μg; 94.7% after 350 μg and 95.2% after 600 μg (p%0.525). Conclusion: At least 350 μg per day is the appropriate oral dose of crystalline vitamin B12 after gastric surgery for obesity to correct low serum vitamin B12 levels in 95% of patients.

Aseptic Necrosis Following Renal Transplantation

In twenty-seven patients who survived for six months or longer following renal homotransplantation, osseous changes developed in ten patients. Nine demonstrated aseptic necrosis of the femoral head, five had involvement of the hips alone, five showed aseptic necrosis at the knee joint, and two had aseptic necrosis of the humeral heads. The average time after transplantation when symptoms arose was seven months and the roentgen changes usually were seen two months later. The etiological explanation based on fatty embolization is theoretically satisfactory but unproved.

Comparison of effect of narcotic and epidural analgesia on postoperative respiratory function

A prospective, randomized comparison was made of the value of meperidine versus epidural analgesia when used for the relief of pain after cholecystectomy in twenty patients without cardiopulmonary disease. Respiratory function was assessed the day before surgery and at 3 to 4 hours and 24 hours after operation by the bedside measurement of expiratory peak flow, vital capacity, and arterial blood gases. The two groups of patients were comparable as to age, height, weight, smoking habits, preoperative peak flow, vital capacity, and duration of operation. The arterial oxygen tension and oxygen saturation were significantly greater and carbon dioxide tension lower in the epidural analgesia group 24 hours after operation. At this time peak flow rates and vital capacity were not different. However, at 3 to 4 hours postoperatively, vital capacity was significantly greater in the epidural anesthesia group. This might account for the differences in arterial blood gases the following day. These findings suggest that epidural analgesia is valuable in the early postoperative period after upper abdominal surgery.

Predicting surgical infection before the operation

To date, simple skin testing using recall antigens has proven to be the most accurate method of assessing preoperative risk for serious infectious complications. When used in conjunction with measures to control the microorganisms and the environment, evaluation of host defense mechanisms with skin testing can aid in reducing postoperative infectious morbidity and mortality.There are 3 possible therapeutic approaches to anergic patients. Surgery and specific nonsurgical treatments (restoration of blood volume, red cell mass, antibiotics), total parenteral nutrition, and immunorestoration. The challenge for the future is to develop the criteria that will indicate the most important defects which account for the anergic state in individual patients.RésuméA l’heure actuelle, les tests d’hypersensibilité cutanée aux antigènes constituent la meilleure méthode pour apprécier avant l’opération le risque de complications infectieuses graves. Cette estimation des mécanismes de défense par les tests cutanés peut, lorsqu’elle est associée à des mesures de contrôle des micro-organismes et du milieu, réduire la morbidité et la mortalité post-opératoire par infection. Trois attitudes thérapeutiques sont possibles chez le malade anergique: chirurgie et traitements spécifiques non chirurgicaux (rééquilibration du volume sanguin et de la masse globulaire, antibiotiques), nutrition parentérale totale et restauration des défenses immunitaires. Dans l’avenir, il faudra essayer de mettre au point des techniques de détection des déficits responsables de l’anergie.

Effect of peritonitis on mitochondrial respiration.

Abstract Rats were exposed to a lethal form of Klebsiella pneumoniae peritonitis and the mitochondrial respiration of their livers was studied either 18 hours after the injection of the organism or immediately after clinical death. No indication of impaired mitochondrial function was found compared to normal controls. The level of high-energy adenine nucleotides was lower than normal in the livers of rats killed at 18 hours and lower still in the group examined at death. The results suggest that this model of experimental sepsis does not cause irreversible damage to liver mitochondria.

Does Genetic Predisposition Influence Surgical Results of Operations for Obesity

Background: There is a familial predisposition to obesity. We wished to document the incidence of obesity (BMI > 40 kg m−2) in the immediate relatives (parents and siblings) of obese patients who were candidates for gastric restrictive surgery. We determined if a familial predisposition to obesity would influence the surgical results. Methods: The height, weight and BMI were obtained in 1841 relatives of obese patients and in 1059 relatives of normal weight controls. The results of gastric surgery after 52.9 ± 23.1 months were obtained in 44 patients with a familial history of obesity and in 34 patients without a familial history. Results: Patients presenting with a BMI > 40 kg m−2 were 24.541 times more likely to have a first degree relative with morbid or super obesity than individuals in the control group. Mothers were twice as likely to be severely obese as fathers. A successful result (BMI < 35 kg m−2 or less than 50% excess weight) occurred 52.9 ± 23.1 months in 77% of patients with a family history of obesity and in 73% of patients without a familial predisposition (p = 0.79). Conclusions: There is a strong familial predisposition to obesity but over one-half of the immediate family members of obese patients have a BMI < 30 kg m−2. Gastric restrictive surgery induces satiety and produces a successful outcome regardless of familial predisposition. Patients who undergo surgery have a remarkably stable weight over the year prior to operation, suggesting they are defending a markedly elevated BMI.

Abnormalities in the cellular phase of blood fibrinolytic activity in systemic lupus erythematosus and in venous thromboembolism

Fibrinolytic activities of whole blood and plasma were determined by 125I-fibrin radiometric assay in 16 normal subjects, and in 11 patients with systemic lupus erythematosus (SLE), 14 with progressive systemic sclerosis (PSS), 23 with venous thromboembolic disease, and 20 patients awaiting elective surgery. Mean whole blood and plasma activities for patients with PSS, and for those awaiting elective surgery, were similar to normal values, as was the mean plasma activity in patients with SLE. However, mean whole blood activity in SLE was significantly decreased compared with normals (p less than 0.05), with mean plasma activity accounting for 44% of mean whole blood activity (compared with 17% in normal subjects), representing a 67% decrease in mean calculated cellular phase activity in SLE, when compared with normals. Since the numbers of cells (neutrophils, monocytes) possibly involved in cellular activity were not decreased, the findings suggest a functional defect in fibrinolytic activity of one or more blood cell types in SLE. An additional finding was the participation of the cellular phase as well as the well-known plasma phase of blood in the fibrinolytic response to thromboembolism.