Acute complications after laparoscopic bariatric procedures: update for the general surgeon

Background

Development and widespread use of laparoscopic bariatric surgery exposes emergency room physicians and general surgeons to face acute or chronic surgical complications of bariatric surgery.

Methods

The most common surgical emergencies after bariatric surgery are examined based on an extensive review of bariatric surgery literature and on the personal experience of the authors' practice in four high-volume bariatric surgery centers.

Results

An orderly stepwise approach to the bariatric patient with an emergency condition is advisable. Resuscitation should follow the same protocol adopted for the non-bariatric patients. Consultation with the bariatric surgeon should be obtained early, and referral to the bariatric center should be considered whenever possible. The identification of the surgical procedure to which the patient was submitted will orient in the diagnosis of the acute condition. Procedure-specific complication should always be taken into consideration in the differential diagnosis. Acute slippage is the most frequent complication that needs emergency treatment in a laparoscopic gastric banding. Sleeve gastrectomy and gastric bypasses may present with life-threatening suture leaks or suture line bleeding. Gastric greater curvature plication (investigational restrictive procedure) can present early complications related to prolonged postoperative vomiting. Both gastric bypass and bilio-pancreatic diversion may cause anastomotic marginal ulcer, bleeding, or rarely perforation and severe stenosis, while small bowel obstruction due to internal hernia represents a surgical emergency, also caused by trocar site hernia, intussusceptions, adhesions, strictures, kinking, or blood clots. Rapid weight loss after bariatric surgery can cause cholecystitis or choledocholithiasis, which are difficult to treat after bypass procedures.

Conclusions

The general surgeon should be informed about modern bariatric procedures, their potential acute complications, and emergency management.     

Validity of model approximations for receptor-ligand kinetics in nuclear medicine

An appropriate mathematical model is required for quantitative analysis of high affinity radioligands as direct or surrogate probes to measure receptor distribution, affinity, concentration, binding potential, and endogenous or exogenous ligand occupancy levels. For studies with positron emission tomography (PET) or single photon emission computed tomography (SPECT), the receptor-ligand compartment model has been well established and widely used. This pharmacokinetic model is represented mathematically by a set of nonlinear ordinary differential equations. Variations of models for PET and SPECT account for radioactive decay differently. These are not equivalent and entail assumptions or approximations that may be not appreciated. In this study, a general form of the model is presented and compared with others with various approximations, which are valid only under specific conditions. The various approximate formulations were analytically compared to the exact model to identify the terms that were neglected in the approximate formulations. The extent to which the approximations impact the model solutions was assessed by computer simulations based on numerical solutions to each set of equations. Specifically, each model formulation was tested using three simulated injection protocols representing a typical PET experiment, a typical SPECT experiment, and an extreme experiment where both the injected activity and the specific activity were very high. No significant differences were found among the output of the three model formulations when the PET and SPECT injection protocols were tested. The only conditions that produced significant differences occurred when the specific activity and the administered activity were simultaneously very high. These conditions, however, have little practical relevance to experimentally achievable conditions due to radiation dose and specific activity of radiopharmaceuticals     

ASO Visual Abstract: Repeat Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Cancers with Peritoneal Metastasis—A 30-year Institutional Experience

Annals of Surgical Oncology -     

Non-invasive high-speed blinking kinematics characterization

Graefe's Archive for Clinical and Experimental Ophthalmology - The objective of this study was to analyze the differences in blinking kinematics of spontaneous and voluntary blinks using for...