Norepinephrine in small-for-size liver grafts: an experimental study in pigs

BACKGROUND: Norepinephrine plasma levels may play a role in small-for-size grafts dysfunction at the early posttransplant period. MATERIALS AND METHODS: The 18 pigs used as recipients were assigned to group 1 (n = 6), group 2 (n = 6), and group 3 (n = 6) and given grafts with graft-to-recipient volume ratios of 1:1, 2:3, and 1:3, respectively. Blood serum norepinephrine was measured by high-performance liquid chromatography with electrochemical detection at the following time points: pre-anhepatic period (baseline); anhepatic period; and 30, 60, 180, and 360 min after reperfusion. Graft arterial and portal vein flows were obtained 30, 60, 180, and 360 min after reperfusion by the aid of an ultrasonic flowmeter. Aspartate transferase (AST) and international normalized ratio (INR) were measured before the procedure (baseline), and at 180 and 360 min after reperfusion. RESULTS: Anhepatic phase was characterized by a significant increase (6- to 8-fold) of norepinephrine in all groups (P < 0.05). In groups 1 and 2 plasma norepinephrine returned to normal values 30 min after reperfusion. In group 3, plasma norepinephrine remained significantly increased at every time point of the study compared to groups 1 and 2 (P < 0.001). Hepatic artery and portal vein flows in group 3 were significantly (P < 0.05) reduced and increased, respectively, compared to groups 1 and 2 at all times measured. Liver function tests (AST and INR) 360 min after reperfusion were significantly higher in group 3 compared to groups 1 and 2. CONCLUSIONS: Norepinephrine levels are increased in very small-for-size grafts and this increase may be associated with early graft dysfunction.     

The role of central venous pressure and type of vascular control in blood loss during major liver resections

BACKGROUND: Blood loss during liver resection constitutes the primary determinant of the postoperative outcome. Various techniques of vascular control and maintenance of a low central vein pressure (CVP) have been used in order to prevent intraoperative blood loss and postoperative complications. Our study aims at assessing the effects of different levels of CVP in relation to type of vascular control on perioperative blood loss and patient outcome. METHODS: The records of 102 consecutive patients who underwent a major hepatectomy were retrospectively analyzed. Forty-two patients were operated on with a CVP of 6 mm Hg or more and 60 patients had a CVP of 5 mm Hg or less. The Pringle maneuver was used in 45 patients and selective hepatic vascular exclusion (SHVE) in 57 patients. Blood loss, complications, and mortality were analyzed comparing the two CVP groups in relation to type of vascular control. RESULTS: The Pringle maneuver is associated with more blood loss when CVP is 6 mm Hg or more compared with CVP 5 mm Hg or less (1,250 mL [250 to 2,850] versus 780 mL [150 to 3,100]; P <0.05). Conversely, blood loss during SHVE is independent of the CVP levels. A significant difference in blood loss between the Pringle maneuver and SHVE was observed, only when CVP was 6 mm Hg or more (1,250 mL [250 to 2,850] versus 680 mL [150 to 1,260]; P <0.05). Hospital stay was also significantly longer in patients operated on with CVP 6 mm Hg or more (15 days [4 to 38] than in patients with CVP 5 mm Hg or less (10 days [4 to 32]; P <0.05). CONCLUSIONS: Elevated CVP during major liver resections results in greater blood loss and a longer hospital stay. The Pringle maneuver with CVP 5 mm Hg or less is associated with blood loss not significantly different from that with SHVE. The latter, though, has been shown not to be affected by CVP levels and should be used whenever CVP remains high despite adequate anesthetic management.     

Combination of diaphragmatic plication with major abdominal surgery in patients with phrenic nerve palsy

The role of simultaneous prophylactic diaphragmatic plication during major abdominal operations is evaluated. In five patients with a history of phrenic nerve injury, postoperative ventilation requirements and hospital stay were significantly reduced when synchronous diaphragmatic plication was performed, compared with corresponding values obtained during previous abdominal operation without diaphragmatic plication. In addition, diaphragmatic plication was associated with postoperative improvement of respiratory mechanics and blood gas exchange.     

Total versus selective hepatic vascular exclusion in major liver resections

BACKGROUND: Total hepatic vascular exclusion (THVE) and selective hepatic vascular exclusion (SHVE) are two effective techniques for bleeding control in major hepatic resections. Outcomes of the two procedures were compared. METHODS: Patients undergoing major liver resection were randomly allocated to the THVE and SHVE groups. Intraoperative hemodynamic changes and the postoperative course of the two groups were compared. RESULTS: During vascular clamping, the THVE group showed a significant elevation in pulmonary vascular resistance, systemic vascular resistance, intrapulmonary shunts, and a significant reduction in cardiac index, compared with the SHVE group (P <0.05). Patients undergoing THVE received more crystalloids and blood, showed more severe liver, renal and pancreatic dysfunction, and had a longer hospital stay than the SHVE group (P <0.05). CONCLUSIONS: Both techniques are equally effective in bleeding control in major liver resections. THVE is associated with cardiorespiratory and hemodynamic alterations and may be not tolerated by some patients. SHVE is well tolerated with fewer postoperative complications and shorter hospitalization time.     

Reversal of Experimental Posthepatectomy Liver Failure in Pigs: A New Application of Hepatocyte Bioreactors

Postoperative liver failure remains a major cause of morbidity and mortality after extensive hepatectomies. This study aims to evaluate the effectiveness of a hepatocyte bioreactor in the treatment of experimental post‐hepatectomy liver failure. Our experimental model included a combination of a side‐to‐side portacaval shunt, occlusion of the hepatoduodenal ligament for 150 min, 70% hepatectomy, and reperfusion. Following the development of liver failure, 12 pigs were randomized into a control group (n = 6) and a treatment group (n = 6). Both groups underwent extracorporeal perfusion through a plasma separation device, a membrane oxygenator, and two parallel bioreactors. In the latter group, the bioreactors were loaded with 10 billion fresh hepatocytes, isolated from a donor pig. Following hepatocyte treatment, all animals were maintained for 24 h under mechanical ventilation, with intravenous fluid and glucose supplementation. Hemodynamic parameters, intracranial pressure, and biochemical parameters were measured. Liver biopsies were obtained during the 24‐h autopsy. The extracorporeal circuit was well‐tolerated hemodynamically. Treated animals had lower intracranial pressure compared with controls (at 24 h, 15 ± 3.1 vs. 22 ± 3.5 mm Hg, P = 0.006). Plasma ammonia in treated animals was lower compared with controls at 12 h (100 ± 29 vs. 244 ± 131 µmol, P = 0.026). Liver histological study showed decreased necrosis and increased regeneration activity in treated animals compared with controls. Treatment through an extracorporeal hepatocyte bioreactor attenuates brain edema and improves histological and functional parameters of the liver remnant of pigs with posthepatectomy liver failure.     

Split liver transplantation: King''s College Hospital experience.

BACKGROUND: The purpose of split liver transplantation is to increase the source of pediatric grafts without compromising the adult donor pool. Early results have been discouraging because of technical complications and selection of poor risk patients. METHODS: The results of a single center experience of 41 split liver transplantations were analyzed. Patient and graft survival and complications related to the technique were analyzed. RESULTS: Patient and graft survival for the whole group was 90% and 88% respectively at a median follow up of 12 months (range 6-70 months). Patient and graft survival for the right lobe graft was 95% and the left lateral segment 86% and 82% respectively. Four patients died, of which two of the patients were first two splits following technical complications. Two others died, one from cerebral lymphoma and the other of multiorgan failure secondary to sepsis. One patient has been retransplanted for chronic biliary sepsis. CONCLUSION: Split liver transplantation has now become an acceptable treatment option for both adult and pediatric recipients with end stage liver disease. Right lobe recipients are not disadvantaged by the procedure. Good results can be achieved with better patient selection and by the use of good quality organs.     

Cystic fibrosis and the phenotypic expression of autosomal dominant polycystic kidney disease

Recent experiments in cultured cyst epithelial cells from kidneys of patients with autosomal dominant polycystic kidney disease (ADPKD) have shown that the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is present in the apical surface of these cells and mediates chloride (Cl-) and fluid secretion in vitro. To determine whether the presence of CF with the expression of mutated CFTR proteins modifies cyst formation in ADPKD, we studied a large family with both inherited diseases. ADPKD in this family is linked to PKD1. The family is composed of 26 members; 11 members with ADPKD, 4 members with CF, and 2 members with both diseases. Renal volumes measured by computerized tomography (CT), calculated creatinine clearances, and other clinical parameters in the family members with ADPKD and CF were compared with those in the family members with ADPKD alone, as well as to a large population of patients with ADPKD. The patients with CF and ADPKD, but not the CF heterozygote carriers with ADPKD, had less severe polycystic kidney and liver disease, as indicated by normal renal function; smaller renal volume, even when corrected for height and body surface area; and the absence of hypertension and liver cysts. These observations suggest that the coexistence of CF may reduce the severity of ADPKD.     

Preoperative Biliary Drainage of Severely Jaundiced Patients Increases Morbidity of Pancreaticoduodenectomy: Results of a Case-Control Study

Background

Recent studies have indicated that preoperative biliary drainage (PBD) should not be routinely performed in patients suffering from obstructive jaundice before surgery. The severity of jaundice that mandates PBD has yet to be defined. Our aim was to investigate whether PBD is truly justified in severely jaundiced patients before pancreaticoduodenectomy. The parameters evaluated were overall morbidity, length of hospital stay, and total in-hospital mortality.

Methods

From January 2000 to December 2012, a total of 240 patients underwent pancreaticoduodenectomy for periampullary tumors. Group A comprised 76 patients with preoperative serum bilirubin ≥15 mg/dl who did not undergo PBD before surgery. Group B comprised another 76 patients, matched for age and tumor localization (papillary vs. pancreatic head) who underwent PBD 2–4 weeks before pancreaticoduodenectomy and were identified from the same database.

Results

Less operative time was required in the ‘no PBD’ group compared with the ‘PBD’ group (210 vs. 240 min). Total intraoperative blood loss and blood transfusions were also significantly less in the ‘no PBD’ group. There was no difference detected in the rate of pancreatic fistula or biliary fistula formation. Group A patients demonstrated significantly lower morbidity than group B (24 vs. 36 %, respectively) and therefore required briefer hospitalization (11 vs. 16 days). Mild infectious complications appear to be the main factor that enhanced morbidity in the PBD group. However, total in-hospital mortality was not significantly different between the two groups.

Conclusions

Even severe jaundice should not be considered as an indication for PBD before pancreaticoduodenectomy, as PBD increases infections and postoperative morbidity, therefore delaying definite treatment.