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Biomedical subjects

D A Mayer

Publications and source records attributed to D A Mayer.

11 recordsLinked to original sources

Improved technique of portal vein reconstruction in pediatric liver transplant recipients with portal vein hypoplasia.

BACKGROUND: Children with small or hypoplastic portal veins represent a challenge for liver transplantation. Graft loss of up to 70% has been reported in these patients in the past. A variety of techniques has been used in both cadaveric and living related transplants in an effort to overcome this problem. Variability arises as to whether to use a vascular graft and where on the portal system to attach the graft. METHOD: We present our usage of a simple and straightforward interposition iliac vein allograft fashioned in a manner to achieve large anastomotic cross-sectional area on the confluence of the superior mesenteric/splenic veins. The procedure also overcomes problems of graft vein/portal vein size mismatch in the cases where liver and vein grafts are procured from much larger donors. RESULTS: A total of 14 children presented with hypoplastic portal vein (diameter<5 mm), of a total of 30 consecutive patients requiring cadaveric liver transplants, and benefited from this technique. Median recipient age was 10.5 months. Revascularization times ranged from 22 to 43 min with a mean of 33 min. All patients are alive and well at a mean follow-up of 329 days (10 months). All liver grafts are well and functioning. No portal vein problem was detected. CONCLUSION: Results from this technique are clearly encouraging. Because portal vein hypoplasia is a common problem in pediatric transplant candidates, we believe this alternative technique is of interest and should be added to the transplant surgeon's armamentarium.

Body Weight↗

Techniques for and outcome of liver transplantation in neonates and infants weighing up to 5 kilograms.

BACKGROUND: Neonates and small infants represent less than 5% of paediatric candidates for liver replacement. Most cases present under urgent conditions and receive grafts from large donors. Surgical techniques must be adapted for adequate graft preparation, vascular reconstruction, and abdominal closure. METHODS: Technical aspects and outcome of 15 liver transplantations in infants weighing less than 5 kg performed at our unit were analysed retrospectively. RESULTS: Liver transplantation was performed under urgent or highly urgent condition in 13 cases. Reduced or split liver grafts were used in all cases (median donor to recipient weight ratio, 9), including a monosegmental graft in 2 cases. In 10 cases, vascular reconstruction was done using a vascular conduit (5, 4, and 1 for artery, portal, and hepatic veins, respectively) and a delayed closure of the abdomen was necessary in 7 children. Postoperative complications were as follows: thrombosis of hepatic artery (n = 1) or portal vein (n = 1), gastrointestinal haemorrhage (n = 2), intraperitoneal bleeding (n = 1), biliary stricture (n = 2), septicaemia (n = 1). Two infants died of brain damage with a functioning graft. One child underwent retransplant for chronic rejection. CONCLUSIONS: Overall, survival rate is 60% (median follow-up, 34 months), which compares favourably with older patient groups when case mix is comparable.

Age Factors↗

Delayed hepatic artery thrombosis in adult orthotopic liver transplantation-a 12-year experience.

BACKGROUND: Although the clinical features of early hepatic artery thrombosis (HAT) are well defined, the features of delayed (more than 4 weeks after transplantation) hepatic artery thrombosis are less clearly defined. The aim of our study was to identify risk factors, clinical presentation, and outcome of management of delayed hepatic artery thrombosis (HAT) after liver transplant (LTx). METHODS: An analysis of prospectively collected data of all patients transplanted from 1986 to 1998 was performed. The importance of recipient (age, sex, primary indication for LTx, cytomegalovirus status, and intraabdominal sepsis) and donor factors (donor age, cold ischemia time, and donor cytomegalovirus status), modes of presentation, and outcome of treatment (biliary reconstruction/stenting, regraft, vascular reconstruction, observation) were analyzed. RESULTS: Delayed HAT was seen in 31/1097 adult LTx recipients (incidence 2.8%). No recipient or donor factors were identified as risk factors. A total of 16 patients were symptomatic at presentation (HAT diagnosed on abdominal ultrasound). Six patients had recurrent episodes of cholangitis, four had cholangitis with a stricture, four had cholangitis and intrahepatic abscesses, and two had bile leaks. Biliary reconstruction was done in six patients (all of whom subsequently required a regraft), vascular reconstruction was performed in two patients (one regrafted and one died shortly after), four patients with cholangitis and stricture on presentation had a biliary stent (all four were later regrafted). A total of 16 patients were regrafted, 9 are alive, 5 died within 6 months (septic at time of LTx), 1 died after 1 year, and 1 died after 2 years. Fifteen patients were asymptomatic and detected on routine screening. 5 have remained asymptomatic and are still alive, 1 developed a biliary stricture that was stented and is alive 105 months later, 4 had recurrence of the original disease, 3 developed progressive graft failure and were listed for transplant but died before regraft due to overwhelming sepsis and hepatic encephalopathy. Two patients died due to nonbiliary sepsis. CONCLUSIONS: Delayed HAT is a rare complication of LTx that may present with biliary sepsis, or remain asymptomatic. Biliary or vascular reconstructions do not increase graft survival. Of the patients who were clinically silent on presentation, 20% developed progressive graft failure requiring a second transplant. A total of 33% survived in the long-term without a second transplant. Ongoing severe sepsis at the time of regraft results in poor survival.

Adolescent↗

Balloon blunt-tip trocar for laparoscopic cholecystectomy: improvement over the traditional Hasson and Veress needle methods.

BACKGROUND AND PURPOSE: Laparoscopic cholecystectomy (LC) is a routine procedure for most general surgeons, yet the technical aspects of gaining access to the peritoneal cavity continue to be quite diverse. We describe a prospective review of 180 LCs using three access techniques: open balloon blunt-tip trocar (BBTT), open Hasson (HA), and closed Veress needle (VN). We favor the BBTT because it is designed to avoid all sharp instrumentation and offers superior seal and mobility, as well as expeditious and easy abdominal access. PATIENTS AND METHODS: The techniques and devices were evaluated prospectively with regard to simplicity of access, leakage of carbon dioxide, access time, and complications. All patients underwent LC by one of two Board-certified surgeons. RESULTS: The mean time to insertion of the laparoscope for the BBTT (3.5 +/- 0.99 minutes) was significantly less than the insertion time for the VN technique (5.2 +/- 0.9 minutes, P < 0.05). The insertion time for the BBTT was also less than for the standard HA approach (4.25 +/- 1.0 minutes; P < 0.05). There were no visceral or vascular injuries noted, but CO2 leakage and subcutaneous insufflation of gas experienced in the standard HA and VN groups resulted in lengthened operative times. One patient in the BBTT group experienced a postoperative port-site herniation, which was repaired primarily without consequence. CONCLUSION: The BBTT is an established, safe alternative to blind access for LC. Our technique is simple and rapid and avoids most of the technical difficulties encountered by other open access devices. We believe this method provides surgeons with an option that is efficient and easier to perform than most other conventional open-access laparoscopic techniques.

Cholecystectomy, Laparoscopic↗

Pacemaker leads: a simple atraumatic method for replacing pacemaker electrodes.

Early dislodgment or malfunction of pacemaker leads can result in significant morbidity and therefore must be corrected promptly. We describe a method of changing pacemaker leads that is atraumatic, maintains central venous access, and eliminates the need for venipuncture. Our technique is simple, highly reproducible, and can be performed with standard operating room instruments.

Electrodes, Implanted↗

Leiomyosarcoma of the pulmonary vein.

OBJECTIVE: We report a case of leiomyosarcoma (LMS) of the pulmonary vein and comment on the natural history and determinants for survival for this rare condition. EXPERIMENTAL DESIGN: Our retrospective review is only the fourth such case reported in the world's literature. SETTING: A teaching hospital with an active surgical residency program. PATIENT OR PARTICIPANT: A 61-year-old female who presented with a central pulmonary mass. INTERVENTIONS: Complete resection without pneumonectomy of cardiopulmonary bypass. Pathology showed low grade LMS. MEASURES: Determinants for survival include complete surgical resection and a low mitotic activity of the tumor. RESULTS: The patient remains no evidence of disease three years following initial treatment. CONCLUSIONS: One reported case of LMS of the pulmonary vein had favorable determinants for survival; complete surgical resection and low mitotic activity of the tumor. These factors may have contributed to the successful outcome. The natural history of LMS of the pulmonary vein appears similar to the more widely studied LMS of the inferior vena cava.

Female↗

Case study: gluteal abscess due to Crohn's disease.

Spontaneous retroperitoneal abscess as a result of Crohn's disease does not always terminate at the psoas or iliac spaces. The abscess may continue downward breaching the obturator fascia. Passage through the sciatic foramina can result in a buttock or posterior upper thigh abscess. This possibility is illustrated in the case presented by a 40 year old female with toxemia and a fluctuant mass in the right gluteal area. Surgical drainage and control of the sepsis was followed by enterocutaneous fistula formation. Small bowel barium series demonstrated communication of the tracking abscess with the caput cecum. Surgical management consisted of formal ileocolectomy. The pathology report revealed Crohn's disease of the terminal ileum and right colon.

Abscess↗

Carcinoma of the gastric cardia and hiatal hernia.

Carcinoma of the cardia of the stomach in patients with sliding hiatal hernia is a disease of poor prognosis, since symptoms nearly always occur late in its course at an already incurable stage. Eleven cases are reviewed from the records of The New York Hospital-Cornell Medical Center from 1932 to 1975. Resectability of tumor appeared related to shorter interval between onset of symptoms and diagnosis. Barium studies combined with esophagoscopy led to correct preoperative diagnosis of malignancy in all cases.

Adenocarcinoma↗