Laparoscopic distal pancreatic resection.

Laparoscopic resection is not an established treatment for pancreatic tumors. Previous reports, mainly in Europe and Japan, have demonstrated the potential utility of laparoscopic distal pancreatectomy (LDP). However, few reports have been published from the United States. We instituted a pilot program to assess LDP. A total of 11 patients were included from December 2003 to December 2004. All patients were staged with preoperative endoscopic ultrasound and received vaccinations for possible splenectomy. The indications for surgery were as follows: neuroendocrine tumor (n = 7), unspecified tumor (n = 1), and cystic neoplasm (n = 3). All procedures began with diagnostic laparoscopy and intraoperative ultrasound. Three patients underwent laparoscopic enucleation of a discrete pancreatic nodule. In eight patients, LDP was attempted. One patient required conversion to an open procedure. In the other seven patients, the procedure was completed laparoscopically, two with hand-assist. The average operative time was 5 hours and 3 minutes; average length of stay was 5 days; and the splenectomy rate was 57 per cent (n = 4). There was one complication of an infected hematoma. There were no pancreatic leaks, deaths, nor readmissions. LDP with or without splenectomy is feasible and can be performed with minimum morbidity and only slightly increased operative time.

Extended ex vivo myocardial preservation in the beating state using a novel polyethylene glycolated bovine hemoglobin perfusate based solution.

Cardiac preservation for transplantation is generally limited by ischemic hypothermic storage of 4-6 hours. Earlier studies in the authors' laboratory have demonstrated that hypothermic perfusion preservation using a novel oxygen carrying hemoglobin solution may extend preservation times to 8 hours and decrease ischemic injury. The purpose of this study was to compare extended cardiac function after 12 and 24 hours of continuous hypothermic perfusion with a polyethylene glycolated bovine hemoglobin perfusate (PEG-Hb) solution to the clinical standard of hypothermic ischemic preservation. The hearts of 54 anesthetized and intubated New Zealand White rabbits were harvested after cold cardioplegic arrest. Group I (n = 12) hearts were perfused with a PEG-Hb solution at 20 degrees C and 30 mm Hg for 24 hours. Group II (n = 10) hearts were preserved similarly with PEG-Hb for 12 hours. Group III (n = 12) hearts were preserved for 8 hours with PEG-Hb; Group IV (n = 10) were preserved by cold ischemic storage for 4 hours at 4 degrees C; and Group V (n = 10) were tested after fresh extirpation. Left ventricular (LV) function was measured in the nonworking state at 15 minute, 1 hour, and 2 hour intervals after transfer to a standard crystalloid Langendorff circuit. Developed LV pressure at 0.5 ml LV volume was superior in Group II at early time points, yet it was similar in all preserved groups at 2 hours. +dP/dt(max) at 0.5 ml LV volume was consistent at all time points and greater in PEG-Hb preserved groups compared with Group V. -dP/dt(max) at 0.5 ml LV volume was significantly greater in Groups II and III compared with Group V initially (p < 0.05), but all were similar at the end of testing. Continuous perfusion preservation of rabbit hearts for time increments up to 24 hours with this novel PEG-Hb solution at 30 mm Hg and 20 degrees C yields LV function that is similar to 4 hours of ischemic hypothermic storage. Extended cardiac perfusion preservation with this PEG-Hb solution deserves further investigation in large animal transplant models.

S-nitrosoglutathione preserves platelet function during in vitro ventricular assist device circulation.

Complications (severe bleeding/thromboembolism) may occur during ventricular assist device (VAD) circulation, caused mainly by platelet dysfunction from platelet activation. We hypothesized that S-nitrosoglutathione (GSNO), having platelet activity preservation properties like nitric oxide (NO), may be a titratable agent to diminish platelet activation and thus preserve platelet function. Dose-response measurement of platelet aggregation by GSNO was performed using an aggregometer. GSNO (1,000 microM) caused inhibition of collagen and ristocetin induced aggregation by approximately 50%. Next, in vitro ventricular assist device (VAD) circulation was performed (over 48 hours using human whole blood), both without (control) and with GSNO (1,000 microM), and the aggregability of perfusate was measured at 0, 0.5, 1, 3, 6, 12, 24, and 48 hours. In control VAD circuits, collagen induced platelet aggregability gradually decreased and became significantly lower after 3 hours of circulation. With GSNO, platelet function did not significantly decrease until after 12 hours. Similar results were seen for ristocetin induced aggregation; control aggregation dropped significantly after 6 hours, but not until after 24 hours with GSNO. Liquid phase measurement of total nitrogen oxides (NO(T)) confirmed added GSNO maintained high perfusate NO(T) compared with control. GSNO is effective in preserving platelet aggregation during the first 12 to 24 hours in vitro and may be effective in preserving platelet function by inhibiting platelet activation during in vivo VAD circulation.

Effects of a novel implantable elastomer device for lung volume reduction surgery in a rabbit model of elastase-induced emphysema.

OBJECTIVES: There is intense interest in lung volume reduction surgery (LVRS) for treatment of severe symptomatic emphysema. LVRS results in objective and subjective improvement in lung function in selected patients. However, LVRS is complicated by substantial morbidity, including prolonged pulmonary air leak associated with resection of emphysematous lung tissue. In this study, we investigated the use of a novel implanted silicone elastomer device that reduces lung volume without surgical resection, in a previously reported emphysematous animal model. The purpose of this investigation was to determine the applicability, physiologic effects, complications, and air-leak results of this lung volume reducer (LVR) approach. DESIGN: Controlled, randomized, prospective animal study. Emphysema was induced in 20 New Zealand white rabbits with three nebulizations of 10,000 U of porcine elastase. After 6 weeks, the animals were randomized to control sham surgery (n = 10) vs implanted silicone elastomer LVR (n = 10) treatment groups. Lung function, including helium-dilution lung volumes, static respiratory system compliance curves, and diffusion capacity of the lung for carbon monoxide (DLCO), was measured at baseline, following emphysema induction (week 6), and when the animals were killed (1 week after LVR or sham surgery). Histologic evaluation was performed in all lung specimens after fixation. RESULTS: Moderate emphysema developed after elastase nebulization, assessed by lung function and postmortem histology. Functional residual capacity (FRC) and an upward shift of lung compliance curves was observed with development of emphysema at 6 weeks (p < 0.05). Following LVR, FRC decreased (p = 0.005) and compliance curves shifted back downward (p = 0.002), without reduction in DLCO. There was no change in control sham animals. DLCO did not change in either group. CONCLUSIONS: In this short-term, randomized, controlled animal model study, the implantable LVR approach produced safe and effective lung volume reduction without tissue resection in the treated animals. The implant procedure produced minimal morbidity, no mortality, and no observed air-leak complications in the treated animals. Limitations include the short-term follow-up and moderate degree of emphysema in this animal model. Further research is required to assess long-term effects and complications of this method for lung volume reduction.