Monopolar stray energy in robotic surgery.

INTRODUCTION: Stray energy transfer from monopolar radiofrequency energy during laparoscopy can be potentially catastrophic. Robotic surgery is increasing in popularity; however, the risk of stray energy transfer during robotic surgery is unknown. The purpose of this study was to (1) quantify stray energy transfer using robotic instrumentation, (2) determine strategies to minimize the transfer of energy, and (3) compare robotic stray energy transfer to laparoscopy. METHODS: In a laparoscopic trainer, a monopolar instrument (L-hook) was activated with DaVinci Si (Intuitive, Sunnyvale, CA) robotic instruments. A camera and assistant grasper were inserted to mimic a minimally invasive cholecystectomy. During activation of the L-hook, the non-electric tips of the camera and grasper were placed adjacent to simulated tissue (saline-soaked sponge). The primary outcome was change in temperature from baseline (°C) measured nearest the tip of the non-electric instrument. RESULTS: Simulated tissue nearest the robotic grasper increased an average of 18.3 ± 5.8 °C; p < 0.001 from baseline. Tissue nearest the robotic camera tip increased (9.0 ± 2.1 °C; p < 0.001). Decreasing the power from 30 to 15 W (18.3 ± 5.8 vs. 2.6 ± 2.7 °C, p < 0.001) or using low-voltage cut mode (18.3 ± 5.8 vs. 3.1 ± 2.1 °C, p < 0.001) reduced stray energy transfer to the robotic grasper. Desiccating tissue, in contrast to open air activation, also significantly reduced stray energy transfer for the grasper (18.3 ± 5.8 vs. 0.15 ± 0.21 °C, p < 0.001) and camera (9.0 ± 2.1 vs. 0.24 ± 0.34 °C, p < 0.001). CONCLUSIONS: Stray energy transfer occurs during robotic surgery. The assistant grasper carries the highest risk for thermal injury. Similar to laparoscopy, stray energy transfer can be reduced by lowering the power setting, utilizing a low-voltage cut mode instead of coagulation mode and avoiding open air activation. These practical findings can aid surgeons performing robotic surgery to reduce injuries from stray energy.

Laparoscopic sleeve gastrectomy: long-term weight loss outcomes.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) has become an increasingly popular stand-alone weight loss surgery, but there is a paucity of long-term efficacy data. OBJECTIVE: To determine long-term outcomes for patients undergoing LSG. SETTING: Tertiary care university hospital in the United States. METHODS: This study presents a case series of the first 16 patients undergoing LSG at our institution. Inclusion criteria were accepted indications for bariatric surgery, and exclusion criteria were any prior bariatric surgery, gastrectomy, substance abuse, uncontrolled psychiatric illness, end-stage organ disease, or advanced-stage cancer. Patients were followed for 7 years. Outcomes included percent excess weight loss (%EWL), percent weight loss (%WL), resolution of co-morbidities, and major and minor complications. RESULTS: Patients enrolled in this study had a mean body mass index (BMI) of 43.5 kg/m(2) and a mean age of 49, and 14 of 16 patients were women. Fourteen of 16 patients had 7-year follow-ups with a mean %WL of 29.6%±8.95 and a mean %EWL of 59.6%±89.9%. At 7 years, 11 of 14 patients achieved>50% EWL. One-year follow-up data revealed a mean EWL of 72%±20%, which was significantly greater than the %EWL at 7 years (P = .005). Complications included 1 partial obstruction at the gastric incisura angularis and 1 subacute leak; both were managed endoscopically. There were no reoperations and no deaths. Five of 14 patients experienced new-onset gastroesophageal reflux disease. CONCLUSIONS: At 7 years postoperative, the LSG remained a durable and successful operation.

Histopathologic staining of low temperature cutaneous burns: comparing biomarkers of epithelial and vascular injury reveals utility of HMGB1 and hematoxylin phloxine saffron.

Histopathology remains the gold standard for evaluation of burn depth, progression, and healing, but burn literature offers little guidance on the best stains for analysis of these complex and evolving injuries. A battery of histochemical and immunohistochemical stains was compared on adjacent sections to determine the best stains for histopathologic study and imaging of burns. Using a validated porcine model of vertical burn progression, full-thickness cutaneous biopsies were stained using hematoxylin and eosin, Hematoxylin phloxine saffron (HPS), Masson Trichrome, Elastin Von Gieson, Movatt's Pentachrome, vimentin, CD31, KI-67, caspase 3a, and high mobility group box 1. Depth of collagen degeneration, cellular necrosis, apoptosis, and vascular occlusion; and reparative processes of cellular hyperplasia, reepithelialization, and new collagen deposition were measured by ocular microscopy. High mobility group box 1 was superior for necrosis between 1 and 24 hours postburn. Vimentin underestimated necrosis until 48 hours postburn. For overall assessment, hematoxylin and eosin and HPS were comparable, except for analysis of thermally injured collagen, vessel occlusion, erythrocyte extravasation, and polariscopic study of collagen deposition, where HPS was superior. HPS stain offers specific advantages in histopathologic burn analysis. Inexpensive and rapid to produce, HPS allows users to analyze eosinophilic components more precisely than standard hematoxylin and eosin.