Transfusion-free Strategies in Liver and Pancreatic Surgery: A Predictive Model of Blood Conservation for Transfusion Avoidance in Mainstream Populations.

OBJECTIVE: The objective of this study is to (1) describe the techniques and prove the feasibility of performing complex hepatobiliary and pancreatic surgery on a Jehovah Witness (JW) population.  (2) Describe a strategy that offsets surgical blood loss by the manipulation of circulating blood volume to create reserve whole blood upon anesthesia induction. BACKGROUND: Major liver and pancreatic resections often require operative transfusions. This limits surgical options for patients who do not accept major blood component transfusions. There is also growing recognition of the negative impact of allogenic blood transfusions. METHODS: A 23-year, single-center, retrospective review of JW patients undergoing liver and pancreatic resections was performed. We describe perioperative management and patient outcomes. Acute normovolemic hemodilution (ANH) is proposed as an important strategy for offsetting blood losses and preventing the need for blood transfusion. A quantitative mathematical formula is developed to provide guidance for its use. RESULTS: One hundred one major resections were analyzed (liver n=57, pancreas n=44). ANH was utilized in 72 patients (liver n=38, pancreas n=34) with median removal of 2 units that were returned for hemorrhage as needed or at the completion of operation. There were no perioperative mortalities. Morbidity classified as Clavien grade 3 or higher occurred in 7.0% of liver resection and 15.9% of pancreatic resection patients. CONCLUSIONS: Deliberate perioperative management makes transfusion-free liver and pancreatic resections feasible. Intraoperative whole blood removal with ANH specifically preserves red cell mass, platelets, and coagulation factors for timely reinfusion. Application of the described JW transfusion-free strategy to a broader general population could lessen blood utilization costs and morbidities.

Combined surgical resection and radiofrequency ablation as treatment for metastatic ocular melanoma.

PURPOSE: Ocular melanoma is a rare disease with a strong predilection for the liver. Systemic and locoregional treatments for metastatic ocular melanoma have had disappointing results, with an average survival of 5-7 months. Resection and/or radiofrequency ablation (RFA) of liver lesions were attempted to improve the patient outcomes. METHODS: Eight patients with liver metastasis from ocular melanoma underwent surgery and/or RFA at the University of Southern California, University Hospital from 1 January 2001 to 31 December 2009. Their charts were retrospectively reviewed. RESULTS: All patients had undergone eye enucleation as the primary treatment. Four patients had all metastatic liver lesions addressed: one patient underwent left lateral segmentectomy and three patients had combinations of left lateral segmentectomies, wedge resections and RFA of two to four lesions. Two patients underwent surgical biopsies for diagnosis, one patient was unresectable and one patient underwent RFA of a dominant lesion. The median survival was 36 months. The median survival of patients who underwent surgery alone or in conjunction with RFA to address all liver lesions was 46 months. CONCLUSIONS: There are few reports of RFA for metastatic ocular melanoma. RFA of liver lesions in addition to resection can perhaps lead to improved survival and may play a critical role in the future management of this disease.

A computational study of conformational interconversions in 1,4-dithiacyclohexane (1,4-dithiane).

Ab initio molecular orbital theory with the 6-31G(d), 6-31G(d,p), 6-31+G(d), 6-31+G(d,p), 6-31+G(2d,p), 6-311G(d), 6-311G(d,p), and 6-311+G(2d,p) basis sets and density functional theory (BLYP, B3LYP, B3P86, B3PW91) have been used to locate transition states involved in the conformational interconversions of 1,4-dithiacyclohexane (1,4-dithiane) and to calculate the geometry optimized structures, relative energies, enthalpies, entropies, and free energies of the chair and twist conformers. In the chair and 1,4-twist conformers the C-Hax and C-Heq bond lengths are equal at each carbon, which suggest an absence of stereoelectronic hyperconjugative interactions involving carbon-hydrogen bonds. The 1,4-boat transition state structure was 9.53 to 10.5 kcal/mol higher in energy than the chair conformer and 4.75 to 5.82 kcal/mol higher in energy than the 1,4-twist conformer. Intrinsic reaction coordinate (IRC) calculations showed that the 1,4-boat transition state structure was the energy maximum in the interconversion of the enantiomers of the 1,4-twist conformer. The energy difference between the chair conformer and the 1,4-twist conformer was 4.85 kcal/mol and the chair-1,4-twist free energy difference (deltaG degrees (c-t)) was 4.93 kcal/mol at 298.15 K. Intrinsic reaction coordinate (IRC) calculations connected the transition state between the chair conformer and the 1,4-twist conformer. This transition state is 11.7 kcal/mol higher in energy than the chair conformer. The effects of basis sets on the 1,4-dithiane calculations and the relative energies of saturated and unsaturated six-membered dithianes and dioxanes are also discussed.