David P. Al-Adra

Treatment of gastric cancer with peritoneal carcinomatosis by cytoreductive surgery and HIPEC: A systematic review of survival, mortality, and morbidity

Gastric cancer with peritoneal carcinomatosis has an extremely poor prognosis, which may be improved with cytoreductive surgery (CRS) combined with heated intraperitoneal chemotherapy (HIPEC). We systematically reviewed the literature regarding the efficacy of CRS + HIPEC in these patients. Electronic databases were searched from 2000 to 2010. Following CRS + HIPEC, overall median survival was 7.9 months and improved to 15 months for patients with completeness of cytoreduction scores of 0/1, however with a 30‐day mortality rate of 4.8%. J. Surg. Oncol. 2011; 104:692–698.

The benefits of bariatric surgery in obese patients with hip and knee osteoarthritis: a systematic review

Osteoarthritis is a common progressive disease leading to joint pain and severe disability. It is a complex multifactorial disease leading to damage of cartilage, deposition of subchondral bone matrix and release of pro‐inflammatory cytokines. Obesity is an emerging epidemic and also an important risk factor for osteoarthritis. Weight loss has been shown to improve pain and function in hip and knee joints with osteoarthritis. Bariatric surgery currently is the only evidence‐based approach to marked weight loss in obese individuals. However, there is currently limited literature to evaluate the role of bariatric surgery in hip and knee osteoarthritis. The objective of the present study was to systematically review the literature regarding the effectiveness of bariatric surgery in obese adult patients in improving large weight‐bearing joint (hip and knee) osteoarthritis. Published English‐language manuscripts were considered for review inclusion. A comprehensive search of electronic databases using broad search terms was completed. From a total of 400 articles, eight articles were identified. A total of six studies were included for qualitative analysis. A general trend was identified indicating improved hip and knee osteoarthritis following marked weight loss secondary to bariatric surgery. This systematic review demonstrates that bariatric surgery may benefit obese patients with hip or knee osteoarthritis. However, this review identifies the need for randomized controlled trials to clarify the role and indications for bariatric surgery.

Single-incision appendectomy is comparable to conventional laparoscopic appendectomy: a systematic review and pooled analysis.

Purpose: Acute appendicitis remains the common gastrointestinal emergency in adults. Single-incision laparoscopic appendectomy (SILA) has been proposed as the next evolution in minimally invasive surgery. SILA is postulated to reduce postoperative pain and enhance cosmesis, while effectively removing an inflamed appendix. However, the efficacy and benefits of SILA compared with conventional laparoscopic appendectomy (CLA) remain to be determined. Our objectives were to systematically review the literature comparing SILA with CLA for acute appendicitis and perform a pooled analysis on the efficacy of SILA. Methods: Published English-language manuscripts were considered for review inclusion. A comprehensive search of electronic databases (eg, MEDLINE, EMBASE, SCOPUS, BIOSIS Previews, and the Cochrane Library) using broad search terms was completed. All comparative studies were included if they incorporated adult patients undergoing appendectomy for acute appendicitis by SILA. The primary outcomes of interest were operative time and length of hospital stay. Results: From a total of 366 articles, 34 articles were identified. A total of 9 comparative studies were included for pooled analysis. There was no significant difference in operative time, length of stay, pain scores, and conversion or complication rates between SILA and CLA for acute appendicitis. Conclusions: This systematic review and pooled analysis demonstrates that SILA is comparable to CLA for acute appendicitis in adults. However, this review identifies the need for randomized controlled trials to clarify the efficacy of SILA compared with CLA.

Predictors of attrition in a multidisciplinary adult weight management clinic

BACKGROUND Worldwide, more than 1.7 billion individuals may be classified as overweight and are in need of appropriate medical and surgical treatments. The primary goal of a comprehensive weight management program is to produce sustainable weight loss. However, for such a program to be effective, the patient must complete it. We analyzed attrition rates and predictors of attrition within a publicly funded, multidisciplinary adult weight management program. METHODS We retrospectively reviewed charts from an urban multidisciplinary adult weight management clinic program database. Patients received medical or surgical treatment with appropriate follow-up. We collected information on demographics and comorbidities. Patients in the surgical clinics received either laparoscopic gastric band insertion or gastric bypass. We conducted univariate analysis and multivariate analyses on predictors of attrition. RESULTS A total of 1205 patients were treated in the weight management program: 887 in the medical clinic and 318 with surgery and follow-up in a surgical clinic. Overall, 516 patients left the program or were lost to follow-up (attrition rate 42.8%). The attrition rate was 53.9% in the medical clinic and 11.9% in the surgical clinic. Multivariate analyses identified participation in the medical clinic, younger patient age and lower body mass index as predictors of attrition. CONCLUSION We found lower attrition rates among surgically than medically treated patients in a multidisciplinary weight management clinic. Further research is needed to understand those variables that lead to improved attrition rates.

Single-Donor Islet Transplantation and Long-term Insulin Independence in Select Patients With Type 1 Diabetes Mellitus:

Background Islet transplantation is a recognized treatment option for select patients with type I diabetes mellitus. However, islet infusions from multiple donors are often required to achieve insulin independence. Ideally, insulin independence would be achieved routinely with only a single donor. Identification of factors associated with insulin independence after single-donor islet transplantation may help to select recipient-donor combinations with the highest probability of success. Methods Subjects undergoing islet transplantation at a single center (Edmonton, Canada) between March 1999 and August 2013 were included. Recipient, donor, and transplant characteristics were collected and compared between recipients who became insulin independent after one islet transplantation and those who did not. Results Thirty-one patients achieved insulin independence after a single-donor islet transplantation, and 149 did not. Long-term insulin-free survival was not different between the groups. Factors significantly associated with single-donor success included recipient age, insulin requirement at baseline, donor weight, donor body mass index, islet transplant mass, and peritransplant heparin and insulin administration. On multivariate analysis, pretransplantation daily insulin requirements, the use of peritransplantation heparin and insulin infusions, and islet transplant mass remained significant. Conclusion We have identified clinically relevant differences defining the achievement of insulin independence after single-donor transplantation. Based on these differences, a preoperative insulin requirement of less than 0.6 U/kg per day and receiving more than 5,646 islet equivalents (IEQ)/kg have a sensitivity of 84% and 71% and specificity of 50% and 50%, respectively, for insulin independence after single-donor islet transplantation. With ideal patient selection, this finding could potentially increase single-donor transplantation success and may be especially relevant for presensitized subjects or those who may subsequently require renal replacement.

Mixed chimerism and split tolerance: Mechanisms and clinical correlations

Establishing hematopoietic mixed chimerism can lead to donor-specific tolerance to transplanted organs and may eliminate the need for long-term immunosuppressive therapy, while also preventing chronic rejection. In this review, we discuss central and peripheral mechanisms of chimerism induced tolerance. However, even in the long-lasting presence of a donor organ or donor hematopoietic cells, some allogeneic tissues from the same donor can be rejected; a phenomenon known as split tolerance. With the current goal of creating mixed chimeras using clinically feasible amounts of donor bone marrow and with minimal conditioning, split tolerance may become more prevalent and its mechanisms need to be explored. Some predisposing factors that may increase the likelihood of split tolerance are immunogenicity of the graft, certain donor-recipient combinations, prior sensitization, location and type of graft and minimal conditioning chimerism induction protocols. Additionally, split tolerance may occur due to a differential susceptibility of various types of tissues to rejection. The mechanisms involved in a tissue’s differential susceptibility to rejection include the presence of polymorphic tissue-specific antigens and variable sensitivity to indirect pathway effector mechanisms. Finally, we review the clinical attempts at allograft tolerance through the induction of chimerism; studies that are revealing the complex relationship between chimerism and tolerance. This relationship often displays split tolerance, and further research into its mechanisms is warranted.

Robotic‐assisted bariatric surgery: a systematic review

Bariatric laparoscopic surgery has been shown to lead to sustainable weight‐loss in obese individuals. Robotic‐assisted laparoscopic surgery is proposed as the next major evolution in minimally invasive surgery. This study systematically reviews the literature regarding the feasibility and safety of robotic‐assisted bariatric surgery in obese patients.

The Impact of Bariatric Surgery in Patients with Type-2 Diabetes Mellitus

Over 220 million individuals have type-2 diabetes mellitus (T2DM) worldwide. Obesity has been identified as a significant risk factor for the development of T2DM. Overweight or obese individuals develop insulin resistance with resultant hyperinsulinemia. This process may progress to impaired glucose intolerance and eventual T2DM. There is strong evidence indicating that bariatric surgery may produce sustainable long-term weight loss in obese individuals. Bariatric surgery consists of surgical operations classified as either primarily restrictive or malabsorptive. Restrictive bariatric procedures include gastric banding or sleeve gastrectomy, while malabsorptive procedures included gastric bypass and biliopancreatic diversion. Malabsorptive procedures have been shown to be superior in producing dramatic weight loss along with resolution or improvement of T2DM. Interestingly, improvement of diabetes has been shown to occur shortly following malabsorptive bariatric surgery, prior to significant weight loss, suggesting that hormone-mediated mechanisms may be involved. As the prevalence of obesity and T2DM continues to rise, so may the role of bariatric surgery to combat this growing epidemic.

Hydrostatic rectosigmoid perforation: a rare personal watercraft injury

Personal watercrafts (PWC), also known as jet skis, seadoos, and wave-runners have risen in popularity since their introduction in the 1970s. Hydrostatic rectal injury is a rare presentation of passengers thrown off a PWC. The perforation of the rectum is owing to the excessive hydrostatic force of water exerted through the anal canal. We present the first case of rectosigmoid perforation secondary to PWC hydrostatic injury in Canada. A 14-year-old female passenger presented to the pediatric trauma center with severe abdominal pain and blood per rectum following a fall off the back of a PWC at a local lake. Computed tomography of the abdomen and pelvis demonstrated a laceration in the anterolateral rectal wall at the rectosigmoid junction with associated free intra-peritoneal air and profuse free fluid. At exploratory laparotomy, a full thickness perforation was identified at the rectosigmoid junction. The rectum was oversewn as a Hartman pouch, and a proximal end colostomy was performed to divert the fecal stream. Management of traumatic pediatric rectal injuries involves detailed perineal examination with proctoscopy, and if warranted, exploratory laparotomy. Despite the rare occurrence of hydrostatic rectal perforations in Canada, it is a serious and potentially devastating injury. In the United States, the National Transportation Safety Board recommends wet suit bottoms for all pediatric PWC operators and passengers. In Canada, similar recommendations have not been made. The use of PWC in Canada is less common than in the US. However, it is steadily increasing, especially on local lakes. Education regarding potential injuries and prevention is recommended.

Nonobese diabetic natural killer cells: a barrier to allogeneic chimerism that can be reduced by rapamycin.

Background. Induction of allogeneic hematopoietic chimerism is a promising strategy to induce tolerance to donor islets for treating type 1 diabetes. Successful induction of chimerism requires overcoming host alloimmunity. In diabetes-prone nonobese diabetic (NOD) mice, this is challenging due to their general tolerance resistance. Although the adaptive alloimmunity of NOD mice is a known barrier to allogeneic chimerism, whether NOD natural killer (NK) cells are an additional barrier has not been examined. Because NOD NK cells exhibit functional defects, they may not inhibit chimerism generation. Methods. Antibody depletion of NK cells in vivo, or transplantation of F1 hybrid donor cells to eliminate the “missing-self” trigger of NK cells, was preformed to test the NK-mediated rejection of donor bone marrow cells. We also studied the capacity of rapamycin to block the NK cell response against allogeneic cells in vivo. Results. Depleting NK cells or rendering them unresponsive to the donor greatly improved the level of chimerism obtained in NOD mice. Rapamycin significantly reduced the resistance to allogeneic chimerism mounted by NOD NK cells; however, it was much less effective than NK cell depletion by antibodies. Conclusions. Contrary to the view that NOD NK cells are defective, we found these cells to be a substantial barrier to allogeneic chimerism in the presence or absence of adaptive immunity. Moreover, rapamycin will need to be combined with other approaches to fully overcome the NK cell barrier.