Donor gender does not affect liver transplantation outcome in children

The liver is recognized as a sex hormone-responsive organ. Gender-specific differences in liver function are known to exist. Recently, a higher failure rate for organs transplanted in adults from female donors to male recipients has been reported. This increased failure rate of livers obtained from adult females and transplanted into adult males is thought to occur, at least in part, as a result of intrinsic gender-specific differences in hepatocyte cell surface expression and to alterations in the hormonal milieu of the donor liver in the recipient. To determine whether the same graft-recipient gender-determined failure rates pertain in the pediatric liver transplant population, the outcome of 335 primary liver transplants performed in children at the University of Pittsburgh Medical Center was examined. No difference in transplant outcome was demonstrated in children based on the gender pairings between the donor and recipient whether or not variables such as the age, etiology of the liver disease, and the blood group of the recipient were included in the data analysis. Thus, in contrast, to the situation in adults, the gender of the donor does not influence the outcome of liver transplantation in children and should not be used as a criterion for donor selection. This difference between adults and children may be due, at least in part, to gender differences in hepatocyte phenotypic expression induced as a consequence of puberty.Supported by Research Grants from the Veterans Administration Project grant DK 29961 from the National Institutes of Health NIDDK 32556.     

Unconjugated bilirubin in hepatic bile with brown pigment gallstones and cholangitis

To investigate the role of cholangitis in hydrolysis of bilirubin in bile with brown pigment gallstones, bilirubin composition and bacterial growth in hepatic bile with and without cholangitis were studied. The study included 38 brown pigment gallstone cases (28 without cholangitis and 10 with cholangitis). The proportion of unconjugated bilirubin in hepatic bile with cholangitis (16.9±8.5%, mean ± SD) was significantly higher than that without cholangitis (3.7±1.8%, P<0.001. A positive correlation was found between bacterial population with -glucuronidase activity and the proportion of unconjugated bilirubin in bile in cases of brown pigment stones with cholangitis P<0.05) but not in those without cholangitis despite the fact that bacterial species and population are similar regardless of the presence of cholangitis. In cholangitis, pH of bile becomes lower toward the optimal pH of bacterial -glucuronidase. Together the lower concentration of bile acid and the lower pH in bile result in lower solubility of unconjugated bilirubin, promoting its precipitation. Thus occasional bouts of cholangitis may result in periodic deposition of bilirubinate on brown pigment stones with layered structures by inducing cyclic changes of bile composition in situ.     

Versatility of the free anterolateral thigh flap for reconstruction of soft-tissue defects: review of 140 cases

From August 1995 to June 1999, 140 free anterolateral thigh (ALT) flaps were transferred to reconstruct a variety of soft-tissue defects. The size of ALT flap ranged from 10 to 33 cm in length and 4 to 14 cm in width. Based on the anatomic variations of the perforators, the blood supply to the skin island came from the septocutaneous perforators only in 19 patients (13.6%), arising from the descending or transverse branch of the lateral circumflex femoral artery (LCFA), or originating directly from LCFA. The other flaps were supplied by musculocutaneous perforators that were elevated as a true perforator flap via intramuscular dissection (N = 34, 24.3%), or used a cuff of vastus lateralis muscle for added bulk (N = 87, 62.1%). The overall success rate was 92% (129 of 140). After a 2-year follow-up, all flaps have healed unevenffully and donor thigh morbidity is minimal. Anatomic variations must be considered if the ALT flap is to be used safely and reliably.     

The Effect of Hyaluronan-Based Agents on Adhesion Formation in an Intraabdominal Sepsis Model

Because of the technical difficulty during subsequent surgical intervention, adhesion remains the most important predictor of outcome in the staged procedures following emergent colorectal surgery. The aim of this study was to assess the long-term effects of hyaluronan (HA)-based adhesion barriers 3 months following the infectious insult to the peritoneal cavity. Wistar albino rats were divided into three sham and four infectious groups, each consisting of 20 rats. Sham groups consisted of a control group (I), which had undergone manipulation of the cecum in the first operation and saline irrigation following the cecal resection in the second operation; an HA-based bioresorbable membrane (BM) group (II), in which 20 x 20- and 35 x 25-mm pieces of HA-based bioresorbable membrane were placed over the cecectomy area and under the midline incision, respectively, with other conditions the same as for the control (I) group; and an HA-based solution (S) group (II), where HA solution was used as an irrigation solution, with other conditions the same as for the control group (I). Infectious groups consisted of a septic group (IV), which had undergone cecal ligation and puncture in the first operation and saline irrigation following the cecal resection in the second operation; a sepsis + HA-BM group (V), in which two sheets of membrane were applied, with other conditions the same as for the septic group (IV); a sepsis + HA-S group (VI), in which HA solution was used as an irrigation solution, with conditions otherwise the same as for the septic group (IV); and a sepsis + HA-BM + HA-S group (VII), where HA solution was used as an irrigation solution and two sheets of membrane were applied, with other conditions the same as for the septic group (IV). At the end of the 3-month period, mortality, septic complications, and intraabdominal adhesions (adhesion scores and adhesion tensile strength measurements) were recorded. Significantly denser adhesions were found in the septic group (IV) when compared to the others (P < 0.001). HA-S significantly reduced not only the incidence of adhesion but also the adhesion tensile strength in infectious groups (P < 0.001 compared to the sepsis group). However, HA-BM significantly reduced adhesion tensile strength only. Irrigation of the peritoneal cavity with HA-S may prove to be useful to shorten the reversal time period and decrease morbidity following staged procedures for intraabdominal sepsis.     

The gracilis myocutaneous free flap in swine: An advantageous preclinical model for vascularized composite allograft transplantation research

Vascularized composite allotransplantation (VCA) has become a clinical reality, prompting research aimed at improving the risk‐benefit ratio of such transplants. Here, we report our experience with a gracilis myocutaneous free flap in Massachusetts General Hospital miniature swine as a preclinical VCA model. Fourteen animals underwent free transfer of a gracilis myocutaneous flap comprised of the gracilis muscle and overlying skin, each tissue supplied by independent branches of the femoral vessels. End‐to‐end anastomoses were performed to the common carotid artery and internal jugular vein, or to the femoral vessels of the recipients. Thirteen of fourteen flaps were successful. A single flap was lost due to compromise of venous outflow. This model allows transplantation of a substantial volume of skin, subcutaneous tissue, and muscle. The anatomy is reliable and easily identified and harvest incurs minimal donor morbidity. We find this gracilis myocutaneous flap an excellent pre‐clinical model for the study of vascularized composite allotransplantation. © 2012 Wiley Periodicals, Inc. Microsurgery 2013.     

Hypoxia increases reepithelialization via an αvβ6-dependent pathway

Reepithelialization is an essential step in successful cutaneous wound healing. Human keratinocytes, integral in this process, have been shown to have increased motility in the hypoxic healing edge of wounds correlating with the clinical success of semiocclusive hypoxic dressings, although the underlying mechanisms remain poorly understood. Subconfluent human keratinocyte cell monolayers were exposed to 1% hypoxia for up to 24 hours or control conditions. Re-oxygenation studies were performed up to 72 hours. Cellular alphav subunit and alphavbeta6 integrin expression was measured by flow cytometry. Migration scratch assays on fibronectin following hypoxic exposure were performed over 24 hours. Relative matrix metallo-proteinase (MMP)-2, 9 activity was determined by gelatin zymography with TIMP-1 levels assayed by enzyme-linked immunoassay. Sustained increases in alphav and alphavbeta6 expression were shown up to 48 hours in re-oxygenation studies (P < 0.001). Standardized scratch assays confirmed increased migration in the hypoxic group (P < 0.05). This effect was attenuated by the addition of a specific inhibitor of the alphavbeta6 integrin. MMP-2 and -9 activity was up-regulated following hypoxic exposure (P < 0.001; P < 0.05, respectively), whereas increased MMP expression was significantly retarded by addition of an alphavbeta6 inhibitor (P < 0.05). Migration on fibronectin was attenuated by a specific gelatinase inhibitor. We conclude that integrin alphavbeta6-dependent MMP-2 and -9 up-regulation is an important feature of increased migration in hypoxic human keratinocytes.     

Weight Loss Following Vertical Banded Gastroplasty: Intermediate Results of a Prospective Study

Background: Morbidly obese patients who undergo purely restrictive bariatric operations may fail to maintain satisfactory long-term results. In an attempt to achieve the best possible outcome after restrictive procedures, we have employed preoperative selection criteria and are following this selected patient group over time in order to evaluate longterm success. Materials and Methods: From June 1994 through August 2000, 166 morbidly obese patients underwent various bariatric procedures at our institution. Of these patients, 35 underwent vertical banded gastroplasty (VBG) based on selection criteria, including degree of obesity and dietary habits and eating behavior. All patients were seen at 1, 3, 6, 9, and 12 months postoperatively and yearly thereafter. Average follow-up time now is 4.1 years (29-75 mos.), and follow-up is 100%. A multivitamin and mineral supplement is administered to all patients for at least 6 months. Radiology examination is performed in all patients on the 4th postoperative day and at each yearly visit, in order to check for staple-line disruption and stomal stenosis. Results: Early postoperative morbidity was 5.7%. Late postoperative morbidity was 22.8%. A significant number of patients had some degree of stomal stenosis as shown by radiology examination, but to date there has been no need for surgical revision. There has been no early or late mortality.Weight loss results expressed as average percent excess weight loss (% EWL) were as follows: 61% (28-90) at 1 year, 61% (20-90) at 2 years, 57% (13-91) at 3 years, 56% (25-87) at 4 years and 37% (24-59) at 5 years following surgery. A significant number of patients with excellent weight loss had a high frequency of vomiting. Evaluation by BAROS showed that 25% of patients had an overall unsatisfactory outcome. Anemia and iron deficiency were found in 46% and 32% ofVBG patients respectively.Recurrence of preexisting comorbidities was significant if lost weight was regained. Conclusions: In spite of preoperative selection of patients for VBG, a significant percentage of patients had poor overall results in terms of weight loss, quality of life, and resolution of preexisting comorbidities. For these reasons and based on the long-term results published by others, VBG is no longer our preferred surgical option in morbidly obese patients.