Incidentally discovered intestinal nonrotation at time of bariatric surgery: Which operation to perform?

BACKGROUND: An incidental finding of intestinal nonrotation at the time of bariatric surgery poses the following 2 dilemmas: (1) which operation to perform, and (2) whether an appendectomy should be performed concurrently. OBJECTIVES: To review the experience of 2 Bariatric Centers of Excellence with laparoscopic sleeve gastrectomy (LSG) in patients with intestinal nonrotation, and to perform a systematic review of the literature on this topic. SETTING: Two Bariatric Centers of Excellence as designated by the Ontario Bariatric Network. METHODS: A chart review of all LSG cases performed in patients with intestinal nonrotation at 2 centers was performed. A systematic review on performing bariatric surgery in patients with intestinal nonrotation/malrotation was conducted using EMBASE and MEDLINE databases. RESULTS: Four patients (.4% of all cases) underwent LSG in the setting of intestinal nonrotation. Two patients underwent a concurrent appendectomy. Three patients developed postoperative gastrointestinal reflux disease and 1 patient required conversion to a laparoscopic Roux-en-Y gastric bypass. A total of 12 retrospective studies with 23 patients were included in the systematic review. Nineteen patients underwent Roux-en-Y gastric bypass, 3 patients underwent a duodenal switch, and 1 patient underwent LSG. Nine patients (41%) underwent a concurrent appendectomy. Reasons cited for not performing an appendectomy include not completely understanding the anatomic defect, being surprised by the discovery of nonrotation, no consent for the procedure, and suboptimal trocar placement for an appendectomy. CONCLUSIONS: LSG is a reasonable alternative to laparoscopic Roux-en-Y gastric bypass in patients with intestinal nonrotation. A concurrent appendectomy may not be necessary in the era of modern cross-sectional imaging for diagnosing acute appendicitis.

Laparoscopic versus open elective repair of primary umbilical hernias: short-term outcomes from the American College of Surgeons National Surgery Quality Improvement Program.

BACKGROUND: Approximately 175,000 umbilical hernia repairs are performed annually in the US. Controversy exists regarding the optimal approach for the elective repair of primary umbilical hernias. OBJECTIVE: The objective of this study was to compare 30-day outcomes of elective primary open (OHR) and laparoscopic (LHR) umbilical hernia repairs, using a prospectively collected dataset. METHODS: We performed a retrospective cohort study using the American College of Surgeons National Surgery Quality Improvement Program Participant Use Files during 2009 and 2010. Current Procedural Terminology and post-operative International Classification of Diseases, Ninth Revision diagnostic codes were used to identify primary umbilical hernia repairs. Primary outcomes included composite endpoints of 30-day mortality, and major and overall complications. Univariate analyses and multivariate logistic regression were performed controlling for relevant patient characteristics. Secondary outcomes included operative time and hospital length of stay (LOS). RESULTS: Overall, 14,652 patients were identified-13,109 (89.5 %) OHR and 1543 (10.5 %) LHR. Univariate analyses of primary outcomes demonstrated similar 30-day morbidity and mortality between groups. In our multivariate model, however, after controlling for body mass index, gender, American Society of Anesthesiologists class, and chronic obstructive pulmonary disease, the odds ratio (OR) for overall complications favored LHR (OR 0.60; p = 0.01). This difference was driven primarily by the reduced wound complication rate in the LHR group [OR 0.41 (0.20, 0.78); p = 0.005]. LHR was associated with significantly longer operative time [57.7 min (SD 32.6) vs. 38.3 min (SD 22.9); p < 0.001], longer LOS [0.29 days (SD 0.68) vs. 0.17 days (SD 1.47); p = 0.001], and an increased rate of respiratory (0.52 vs. 0.10 %; p < 0.001) and cardiac (0.26 vs. 0.05 %; p = 0.005) complications. CONCLUSIONS: This study identified potential decreased total and wound morbidity associated with LHR for elective primary umbilical hernia repairs at the expense of increased operative time, LOS, and respiratory and cardiac complications. These results should be considered within the context of a retrospective study with its inherent risks of bias and limitations.

Effect of preoperative weight loss in bariatric surgical patients: a systematic review.

BACKGROUND: The potential benefit of preoperative weight loss in patients undergoing bariatric surgery has led many bariatric surgeons to recommend an aggressive weight reduction regimen to their patients. Some surgeons might withhold bariatric procedures if a certain threshold of preoperative weight loss is not achieved. It is unclear whether this practice has any scientific evidence supporting it. Our study aimed to examine the current evidence surrounding this issue in a systematic review. The setting was a university hospital. METHODS: A systematic search of multiple databases, including MEDLINE, Google Scholar, EMBASE, the Cochrane Library, and conference proceedings were reviewed, yielding a final total of 27 studies. Of the 27 studies, 7 were prospective studies (2 randomized controlled trials from the same patient population), 14 were retrospective studies (2 chart reviews from the same patient population), 1 was an editorial, and a number were conference presentations. RESULTS: A total of 17 trials, including approximately 4611 patients, deemed preoperative weight loss beneficial, and 10 studies, including 2075 patients, deemed preoperative weight loss to be of no benefit. The operative time was 12.5 minutes shorter for the preoperative weight loss patients undergoing laparoscopic Roux-en-Y gastric bypass. With regard to the effects of preoperative weight loss on postoperative weight loss, 9 studies (39%) reported a positive correlation, and 15 (62.5%) reported no benefit. Nine studies reporting perioperative complications (852 patients) revealed no difference in the complication rates, and 2 studies (1234 patients) suggested a significant decrease was associated with preoperative weight loss. CONCLUSION: This systematic review suggests little evidence is available to support or refute the routine use of preoperative weight reduction in bariatric surgery. Clearly, a large-scale, multicenter, randomized, controlled trial with sufficient power is necessary to clarify this significant aspect of preoperative care.

Postoperative complications following surgery for rectal cancer.

OBJECTIVE: This systematic review was designed to determine postoperative complication rates of radical surgery for rectal cancer (abdominal perineal resection and anterior resection). SUMMARY OF BACKGROUND DATA: Lack of accepted complication rates for rectal cancer surgery may hinder quality improvement efforts and may impede the conception of future studies because of uncertainty regarding the expected event rates. METHODS: All prospective studies of rectal cancer receiving radical surgery published between 1990 and August 2008 were obtained by searching Ovid MEDLINE, EMBASE, as well as ASCO GI, CAGS, and ASCRS meeting abstracts between 2004 and 2008. There was no language restriction. The outcomes extracted were anastomotic leak, pelvic sepsis, postoperative death, wound infection, and fecal incontinence. Summary complication rates were obtained using a random effects model; the Z-test was used to test for study heterogeneity. RESULTS: Fifty-three prospective cohort studies and 45 randomized controlled studies with 36,315 patients (24,845 patients had an anastomosis) were eligible for inclusion. Most of the studies found were based in continental Europe (58%), followed by Asia (25%), United Kingdom (10%), North America (5%), and Australia/New Zealand. The anastomotic leak rate, reported in 84 studies, was 11% (95% CI: 10, 12); the pelvic sepsis rate, in 29 studies, was 12% (9, 16); the postoperative death rate, in 75 studies, was 2% (2, 3); and the wound infection rate, in 50 studies, was 7% (5, 8). Fecal incontinence rates were reported in too few studies and so heterogeneously that numerical summarization was inappropriate. Year of publication, use of preoperative radiation, use of laparoscopy, and use of protecting stoma were not significant variables, but average age, median tumor height, and method of detection (clinical vs. radiologic) showed significance to explain heterogeneity in anastomotic leak rates. Year of publication, study origin, average age, and use of laparoscopy were significant, but median tumor height and preoperative radiation use were not significant in explaining heterogeneity among observed postoperative death rates. With multivariable analysis, only average age for anastomotic leak and year of publication for postoperative death remained significant. CONCLUSIONS: Benchmark complication rates for radical rectal cancer surgery were obtained for use in sample size calculations in future studies and for quality control purposes. Postoperative death rates showed improvement in recent years.

Novel retinoblastoma binding protein RBBP9 modulates sex-specific radiation responses in vivo.

Retinoblastoma (RB) tumor suppressor is a key regulator of apoptosis, a central mediator of the proliferative block induced by ionizing radiation (IR) and a binding target for a variety of proteins that regulate its activity. One of the recently discovered and the least investigated of these is the novel Rb-binding protein RBBP9/BOG. We studied the effects of acute and chronic low dose radiation (LDR) exposure on the induction of RBBP9 and RB signaling pathway in vivo in mouse spleen and found that RBBP9 played a pivotal role in IR responses in vivo. We observed that chronic LDR exposure led to a significant increase of RBBP9 expression in males and a significant decrease in females. Elevated RBBP9 expression in males was paralleled by a pronounced dephosphorylation of RB and a significant drop of PCNA and cyclin A expression. On the contrary, chronic exposure in females led to decreased levels of RBBP9 and increased levels of hyperphosphorylated RB (ppRB) in spleen. Decreased levels of ppRB in spleen of chronically exposed males were correlated with strongly elevated apoptotic rates. In females, the radiation-induced increase of apoptotic index was much less pronounced. Quite surprisingly, the observed sex-specific signaling changes did not result in the sex-specificity of cellular proliferation. The molecular mechanisms and possible repercussions of the radiation-induced sex differences in cellular proliferation and apoptosis are discussed.

In vivo recombination after chronic damage exposure falls to below spontaneous levels in "recombomice".

All forms of cancer are initiated by heritable changes in gene expression. Although point mutations have been studied extensively, much less is known about homologous recombination events, despite its role in causing sequence rearrangements that contribute to tumorigenesis. Although transgenic mice that permit detection of point mutations have provided a fundamental tool for studying point mutations in vivo, until recently, transgenic mice designed specifically to detect homologous recombination events in somatic tissues in vivo did not exist. We therefore created fluorescent yellow direct repeat mice, enabling automated detection of recombinant cells in vivo for the first time. Here, we show that an acute dose of ionizing radiation induces recombination in fluorescent yellow direct repeat mice, providing some of the first direct evidence that ionizing radiation induces homologous recombination in cutaneous tissues in vivo. In contrast, the same total dose of radiation given under chronic exposure conditions suppresses recombination to levels that are significantly below those of unexposed animals. In addition, global methylation is suppressed and key DNA repair proteins are induced in tissues from chronically irradiated animals (specifically AP endonuclease, polymerase beta, and Ku70). Thus, increased clearance of recombinogenic lesions may contribute to suppression of homologous recombination. Taken together, these studies show that fluorescent yellow direct repeat mice provide a rapid and powerful assay for studying the recombinogenic effects of both short-term and long-term exposure to DNA damage in vivo and reveal for the first time that exposure to ionizing radiation can have opposite effects on genomic stability depending on the duration of exposure.

Ischemia/reperfusion induces the recruitment of leukocytes from whole blood under flow conditions.

Ischemia/reperfusion (I/R) occurs in a number of pathological conditions, including myocardial infarction, stroke, and organ transplantation. During the reperfusion phase, leukocytes are recruited into affected tissues, where they can cause tissue damage and organ failure. Various in vitro models have been developed to study the role of adhesion molecules in I/R-mediated leukocyte recruitment. These models traditionally use isolated leukocytes and static conditions and, therefore, may not recapitulate the in vivo situation. We developed two novel in vitro models of I/R-mediated leukocyte recruitment in which leukocyte recruitment was examined using whole blood under shear conditions. Chemical treatments were used to mimic I/R in the first model, while sequential exposure to hypoxia/reoxygenation (H/R) was used to mimic I/R in the second model. We found that leukocytes were recruited from whole blood under shear conditions to endothelial cells treated with chemically induced I/R or H/R. In both models, mRNA for intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin was upregulated. The role of adhesion molecules in leukocyte recruitment differed slightly between the two models, with E-selectin and VCAM-1 playing approximately equal roles in leukocyte recruitment in the chemically induced I/R model and VCAM-1 being a central mediator of leukocyte recruitment in the H/R model.