[The development of extrahepatic portacaval shunt device based on magnetic compression technique through the interventional procedure].

A device of extrahepatic portacaval shunt is introduced. This device is composed of the daughter and parent magnets and the vascular interventional operation equipment. It is based on the principle of magnetic compression technology, through the intervention approach the daughter and mother magnet are moved to the portal vein and inferior vena cava, respectively. Then the two magnets attract and compress the vessel walls of portal vein and inferior vena cava. Two weeks later, the magnets are detached from the vessel wall with a RUPS-set and the portacaval shunt is established. It is mainly used for the treatment of portal hypertension. It belongs to the interventional operation, there is no any foreign body remaining after the portacaval shunt is established, which can maintain long-term patency. Futhermore the portacaval shunt will not be expanded, therefore it can significantly reduce the incidence of hepatic encephalopathy.

Development of a Simple and Active Shunt System in the Anhepatic Stage for Surgical Training of Orthotopic Liver Transplantation.

BACKGROUND: A pig model has been commonly used for technical training for clinical liver transplantation (LT). However, as the healthy pigs have no shunt bypassing the portal vein (PV), it is necessary to complete LT within 30 minutes after shutting off the PV flow. While a model that uses an ex vivo shunt system has been used to alleviate the constraints of the anhepatic phase, it has been often difficult to keep sufficient blood flow rate and prevent the intestinal congestion because the blood vessels were occluded easily with the suction pressure by using the conventional shunt system. METHODS: We designed a portable shunt system and a novel connector that can prevent the blood vessel from occluding. The system can separately control the flow rate of PV and inferior vena cava (IVC) and detect whether the blood vessels were occluded. By reducing the solution volume in the circuit, the effected blood loss ex vivo could be minimized. The stability of this system was verified with 15 medical doctors in an advanced medical professional education course. RESULTS: The system enabled the blood flow to maintain ≥ 20 mL/minute and prevented the intestinal congestion. The perioperative hemodynamics of the recipient were stable without a blood transfusion using 25 to 40 kg pigs. We confirmed that all LT training were completed, even 60 minutes after shutting off the PV flow. CONCLUSIONS: Our system greatly contributed to training on LT for conducting the survival experiments.

Magnetic Anastomosis Rings to Create Portacaval Shunt in a Canine Model of Portal Hypertension.

PURPOSE: This study evaluated a novel magnetic compression technique (magnamosis) for creating a portacaval shunt in a canine model of portal hypertension, relative to traditional manual suture. METHODS: Portal hypertension was induced in 18 dogs by partial ligation of the portal vein (baseline). Six weeks later, extrahepatic portacaval shunt implantation was performed with either magnetic anastomosis rings, or traditional manual suture (n = 9, each). The two groups were compared for operative time, portal vein pressure, and serum biochemical indices. Twenty-four weeks post-implantation, the established anastomoses were evaluated by color Doppler imaging, venography, and gross and microscopic histological examinations. RESULTS: Anastomotic leakage did not occur in either group. The operative time to complete the anastomosis for magnamosis (4.12 ± 1.04 min) was significantly less than that needed for manual suture (24.47 ± 4.89 min, P < 0.01). The portal vein pressure in the magnamosis group was more stable than that in the manual suture group. The blood ammonia level at the end of the 24-week post-implantation observation period was significantly lower in the magnamosis group than in the manual suture group. Gross and microscopic histological examinations revealed that better smoothness and continuity of the vascular intima had been achieved via magnamosis than with manual suture. CONCLUSION: Magnamosis was superior to manual suture for the creation of a portacaval shunt in this canine model of portal hypertension.

The use of Dacron graft for cavo-cavostomy in orthotopic liver transplantation.

The end-to-end "interposition" technique and end-to-side "piggyback" technique are standard approaches to in situ anastomosis during orthotopic liver transplantation. We demonstrate that anastomosis of liver allograft to a Dacron vena cava graft can be a feasible solution if traditional anastomoses cannot be used. A 55-year-old man with end-stage liver failure from alcoholic cirrhosis underwent orthotopic liver transplantation; however, an intraoperative complication during recipient hepatectomy rendered the native vena cava unsalvageable. In addition, the donor vena cava was too short to bridge the caval defect for interposition. We therefore used Dacron for an in situ graft to span the gap, with subsequent anastomosis of the allograft to the prosthetic graft in piggyback fashion. The patient did well postoperatively; his only major complication was late anastomotic stenosis, which was treated successfully with balloon dilatation. Unfortunately the patient became recidivous and expired ten months posttransplant, despite indications of satisfactory allograft function.

Survival and variceal rehemorrhage after shunting support small-diameter prosthetic H-graft portacaval shunt.

This study was undertaken to report variceal rebleeding and survival after small-diameter prosthetic H-graft portacaval shunts (HGPCS) and to compare actual to predicted survival after shunting. Since 1987 we have prospectively followed patients after undergoing HGPCS to treat bleeding varices failing/not amenable to sclerotherapy/banding. One hundred and seventy patients underwent shunting. Cirrhosis was because of alcohol in 56%, hepatitis in 12%, both in 11%, and other causes in 21%. Child class was A for 10%, B for 28%, and C for 62%. Thirty-three patients died by 6 months, 54 by 24 months, 87 by 60 months, and 112 by 10 years, generally because of liver failure. Fifty-one patients are alive at a median of 48.3 months, 76 months +/- 57.8 (mean +/- SD). Variceal rehemorrhage was documented in 3 (2%) patients. By child class, 5-year/10-year survival rates were as follows: A 66.7/33.3%, B 48.6/15.6%, and C 29.2/7.0%. Actual survival was superior to predicted survival (Model for End-Stage Liver Disease [MELD]), (p < 0.001). Variceal rehemorrhage in patients undergoing small-diameter prosthetic H-graft portacaval shunting was very uncommon. Actual survival was superior to predicted survival (MELD). Long-term survival paralleled degree of hepatic function, although long-term survival was possible even with very advanced cirrhosis. Application of HGPCS is encouraged.

Extrahepatic portacaval shunt via a magnetic compression technique: A cadaveric feasibility study.

AIM: To explore the anatomical feasibility of portacaval shunt using a magnetic compression technique (MCT) in cadavers. METHODS: Computed tomography (CT) images of 30 portal hypertensive patients were obtained. The diameters of the portal vein (PV), the inferior vena cava (IVC), and distance between the two structures were measured. Similar measurements were performed on 20 adult corpses. The feasibility of portacaval shunt based on those measurements was analyzed. First stage of the extrahepatic portacaval shunt using MCT was performed on five cadavers. Specifically, the PV and IVC were exposed through an abdominal incision of the cadavers. The parent magnet was introduced from the femoral vein and was delivered into the IVC by an anchor wire and a 5F Cook catheter. The daughter magnet was introduced into the PV through the splenic vein using an interventional guide wire. When the daughter magnet met the parent magnet, they automatically clipped together and the first stage of the portacaval shunt was set up. RESULTS: The average diameters of the PV and the IVC measured from the 30 CT image were 14.39 ± 2.36 mm and 18.59 ± 4.97 mm, respectively, and the maximum and minimum distances between the PV and the IVC were 9.79 ± 4.56 mm and 9.50 ± 4.79 mm, respectively. From 20 cadavers, the average diameters of the PV and the IVC were 14.48 ± 1.47 mm and 24.71 ± 2.64 mm, and the maximum and minimum distances between the PV and the IVC were 10.14 ± 1.70 mm and 8.93 ± 1.17 mm, respectively. The distances between the PV and the IVC from both the CT images and the cadavers were within the effective length of portacaval anastomosis using MCT (30.30 ± 4.19 mm). The PV and IVC are in close proximity to each other with no intervening tissues or structures in between. Simulated surgeries of the first stage using MCT on five cadavers was successfully performed. CONCLUSION: Anatomically, extrahepatic portacaval shunt employing MCT is highly feasible in humans.

An improved nonsuture method for portacaval anastomosis in the rat.

A nonsuture technique is described for performing portacaval anastomoses in rats. Improvements include reduced clamping time on critical vessels, reduced blood loss, uniformly patent anastomoses, easily manufactured buttons, and decreased mortality rates. The new procedure allows a single operator to perform 25 such operations per day, thus substantially increasing the availability of these animals for studies in hepatic metabolism following portacaval anastomoses.

The emergency portacaval H graft in alcoholic cirrhotic patients: influence of shunt diameter on clinical outcome.

Emergency partial portal decompression was achieved with 8 or 10 mm portacaval H graft shunts combined with aggressive collateral ligation in 18 patients in whom bleeding esophageal varices could not be controlled medically. They were compared with 11 similar risk patients undergoing larger diameter portacaval H graft shunts (12 to 14 mm) for the same indications. Variables studied included 90 day operative mortality, hepatic encephalopathy rates, corrected portal pressure, and variceal re-bleeding. Operative mortality was similar in both groups and correlated strongly with Child's class. However, the incidence of portasystemic encephalopathy in survivors was significantly lower after partial decompression than after total decompression. No patient in either group rebled from varices. We conclude from our series of high risk alcoholic cirrhotic patients, that although mortality after partial and total portal decompression is similar, the lower incidence of encephalopathy in survivors suggests that partial decompression has advantages over total decompression when emergency control of variceal bleeding is necessary.

Prospective study of a prosthetic H-graft portacaval shunt.

This study was undertaken to prospectively evaluate the 8-mm Gore-Tex interposition H-graft portacaval shunt. Thirty-six high-risk patients at the University of South Florida-affiliated hospitals received small-diameter shunts because of bleeding esophagogastric varices over a recent 2-year period. Portal vein and portal vein-inferior vena cava gradients were significantly reduced after shunting. These pressure changes were manifested clinically by the absence of variceal rebleeding and improvement of ascites; in addition, the incidence of encephalopathy was low. The 8-mm graft maintained hepatopedal flow in 67% of the patients, but reversal of flow did not result in complications commonly associated with poor portal perfusion. Graft thrombosis occurred in four (11%) patients. All grafts were successfully revised, three by operative revision and one by an interventional radiologist. Operative mortality was low (11%), and morbidity was unusual. The small-diameter H-graft portacaval shunt is a safe and effective method of treatment for bleeding esophagogastric varices.

[The construction and operation of an intravasal deflectable cavoportal puncture catheter. An animal experimental study]. / Bau und Funktionsweise eines intravasal dirigierbaren "kavoportalen" Punktionskatheters. Tierexperimentelle Studie.

Principle and construction of a cavoportal catheter for the intravasal puncture of the portal stem from the caval lumen is presented. This is a prerequisite in the performance of a nonanatomical, extrahepatic communication between these vessels. Experiences in animal trials confirm the proper functioning of this special catheter prototype.

Alternative use of the interposition Dacron grafts in the treatment of portal hypertension. Clinical experience with 28 cases.

Twenty-eight patients suffering from esophageal bleeding due to portal hypertension were submitted to an "H" type shunt utilizing a 12 mm. wide knitted Dacron prosthesis. The series consists of 8 meso-caval, 12 porto-caval 8 spleno-renal shunts. Thrombosis of the spleno-portal axis was the main indication for the mesocaval shunt, while side-to-side porto-caval and spleno-renal "H" anastomoses were carried out in patients in whom enlarged lymphatics, edema of the porta hepatis or a too large gap between the two veins precluded the use of a direct shunt. The overall mortality rate was 7% including one operative and one late death. The long-term follow-up study included 26 patients and ranged from 6 to 34 months. In all patients patency of the shunt was evaluated by barium swallow x-ray and esophagogastroscopy. Four of them were further investigated by angiography. A good patency of the shunt was demonstrated in all cases. There was no recurrence of the variceal bleeding either in the post-operative period nor in the long-term follow-up. On the basis of our results we feel that the use of Dacron grafts as "H" type shunts is an effective alternative method in relieving portal hypertension in patients in whom it is difficult or impossible to perform a direct anastomosis and further this procedure can be extended with encouraging results to side-to-side spleno-renal shunts.

A caval clamp for portacaval shunt in the rat.

An inexpensive caval clamp and stand, designed for use in the performance of portacaval shunt in the rat are described.

Nurses, surgeon not negligent in retained instrument suit. Kissinger v Turner.

Instrument counts are controversial. Though they are recommended on all procedures by the Association of Operating Room Nurses, the majority of hospitals aren't doing them, according to a survey by OR Manager. What happens if you don't have a policy, an instrument is left in, and the case goes to court? What is the role of professional recommendations? The health care law firm of Horty, Springer & Mattern discusses just such a case.