Transjugular intrahepatic portosystemic shunts (TIPS)

Cell Therapy Using Adipose-Derived Stem Cells for Chronic Liver Injury in Mice

The present study investigated whether transplantation of autologous adipose-derived stem cells (ASCs) administered into the systemic circulation of a mouse with chronic liver injury provides therapeutic efficacy in the absence of any undesirable side effects. The ASCs used were isolated from mice with the same genetic background as the recipient mice and expanded in vitro. For the induction of chronic liver injury, mice were repetitively administered twice a week with CCl₄, a well-known hepatotoxin, for a period of 4 weeks. One day after the eighth dose of CCl₄, ASC transplantation was performed by tail vein injection and subsequently followed by two additional doses of CCl₄ administration. The recipient mice were divided into four groups (vehicle control, 1.5×10³, 1.5×10⁴, and 1.5×10⁵ ASCs per mouse). One day after the final CCl₄ administration, all mice were sacrificed to assess serum markers and liver histology. The level of serum markers for liver injury and hepatic function did not differ among the four groups. Similarly, no difference was observed in the liver histology between groups. Cell transplantation with ASCs in our model of chronic liver failure did not result in any observable side effects, but from our results, a single application of ASCs seems to be ineffective in improving liver injury.

Hepatocyte transplantation through the hepatic vein: a new route of cell transplantation to the liver

The efficiency of hepatocyte transplantation into the liver varies with the method of administration. This study investigated whether retrograde infusion via the hepatic vein provides a sufficient number of donor cells for the liver. Donor hepatocytes were isolated from dipeptidyl peptidase IV (DPPIV(+)) rats and transplanted into DPPIV(-) rat livers either by antegrade portal vein infusion or retrograde hepatic vein infusion. Hepatocyte engraftment ratios and localization were evaluated by histological DPPIV enzymatic staining at 1 week and 8 weeks after the transplantation. No significant differences in engraftment efficiency were observed at either 1 week or 8 weeks after transplantation by either route. However, the localization of the transplanted hepatocytes differed with the administration route. Portal vein infusion resulted in predominantly periportal engraftment, whereas hepatic vein infusion led to pericentral zone engraftment. Immunohistochemical analysis showed that the transplanted hepatocytes engrafted in the pericentral zone after retrograde infusion displayed intense CYP2E1 staining similar to the surrounding native hepatocytes. CYP2E1 staining was further enhanced by administration of isosafrole, an inducing agent for various cytochrome P450 enzymes, including CYP2E1. This study demonstrates a novel approach of transplanting hepatocytes into the liver through retrograde hepatic vein infusion as the means to target cell implantation to the pericentral zone.

Hemolysis during percutaneous mechanical thrombectomy can mimic a hemolytic transfusion reaction

BACKGROUND

Interventional radiologists have developed percutaneous mechanical thrombectomy (PMT) devices to remove intravascular thrombi. Hemolysis, secondary to thrombus destruction from these devices, has been described in radiology journals, but similar reports appear to be lacking in the transfusion medicine literature. Two cases of hemolysis after PMT are described that involved the transfusion service, one of which was reported as a hemolytic transfusion reaction.

CASE REPORTS

The first patient received 4 units of red cells (RBCs) during a thrombectomy and subsequent placement of a transjugular intrahepatic portosystemic shunt. The patient developed hemoglobinuria, and it was reported to the blood bank as a possible hemolytic transfusion reaction. After RBC mismatch and bacterial contamination were excluded, the hemolysis was attributed to thrombectomy-related mechanical hemolysis. In the second case, a hemolyzed sample was sent to the blood bank for a type and cross-match. Upon requesting that the sample be redrawn, it was learned that the sample was obtained after PMT.

CONCLUSION

Patients who have undergone PMT can have clinical and laboratory findings suggestive of hemolytic transfusion reactions. Although interventional radiologists are familiar with these side effects, the blood bank profession needs to be aware that these procedures cause nonimmune hemolysis and must consider this possibility when evaluating transfusion reactions in these patients.

Re-Evaluation of a Portocaval Venograft Without an Ameroid Constrictor as a Method for Controlling Portal Hypertension After Occlusion of Intrahepatic Portocaval Shunts in Dogs

OBJECTIVE

To evaluate the use of a portocaval venograft without an ameroid constrictor in the surgical management of intrahepatic portosystemic shunts (PSS).

STUDY DESIGN

Prospective clinical study.

ANIMALS

Seven dogs with intrahepatic PSS.

METHODS

Portal pressure was measured after temporary suture occlusion of the intrahepatic PSS. In dogs with an increase in portal pressure > or =8 mm Hg or signs of portal hypertension, a single extrahepatic portocaval shunt was created using a jugular vein. Clinical outcome and complications were recorded.

RESULTS

The mean (+/-SD) portal pressure increased from 5.9+/-1.6 to 17.9+/-4.1 mm Hg with PSS occlusion. There were no intraoperative complications and, after creation of the portocaval shunt, the intrahepatic PSS could be completely ligated in all dogs. The final portal pressure was 9.6+/-1.9 mm Hg. Complications developed during postoperative hospitalization in 5 dogs and included incisional discharge (4 dogs), ascites (3), ventricular premature contractions (2), and melena, bloody diarrhea, neurologic signs, coagulopathy, and aspiration pneumonia (each in 1 dog). Six dogs died or were euthanatized with clinical signs related to depression, inappetance, abdominal pain, vomiting, melena, and abdominal distention, with a median survival of 82 days (range, 20-990 days). One dog was clinically normal at 33 months after surgery.

CONCLUSIONS

Clinical signs observed in 6 dogs after surgery were consistent with portal hypertension. Use of a portocaval venograft without an ameroid constrictor may reduce the likelihood of hepatic vascular development, thereby increasing the risk of life-threatening portal hypertension should the venograft suddenly occlude.

CLINICAL RELEVANCE

Use of a portocaval venograft without an ameroid constrictor to control portal hypertension after ligation of an intrahepatic PSS cannot be recommended.

Technology improvements for image-guided and minimally invasive spine procedures

This paper reports on technology developments aimed at improving the state of the art for image-guided minimally invasive spine procedures. Back pain is a major health problem with serious economic consequences. Minimally invasive procedures to treat back pain are rapidly growing in popularity due to improvements in technique and the substantially reduced trauma to the patient versus open spinal surgery. Image guidance is an enabling technology for minimally invasive procedures, but technical problems remain that may limit the wider applicability of these techniques. The paper begins with a discussion of low back pain and the potential shortcomings of open back surgery. The advantages of minimally invasive procedures are enumerated, followed by a list of technical problems that must be overcome to enable the more widespread dissemination of these techniques. The technical problems include improved intraoperative imaging, fusion of images from multiple modalities, the visualization of oblique paths, percutaneous spine tracking, mechanical instrument guidance, and software architectures for technology integration. Technical developments to address some of these problems are discussed next. The discussion includes intraoperative computerized tomography (CT) imaging, magnetic resonance imaging (MRI)/CT image registration, three-dimensional (3-D) visualization, optical localization, and robotics for percutaneous instrument placement. Finally, the paper concludes by presenting several representative clinical applications: biopsy, vertebroplasty, nerve and facet blocks, and shunt placement. The program presented here is a first step to developing the physician-assist systems of the future, which will incorporate visualization, tracking, and robotics to enable the precision placement and manipulation of instruments with minimal trauma to the patient.

Biliary-venous fistula complicating transjugular intrahepatic portosystemic shunt presenting with recurrent bacteremia, jaundice, anemia and fever

A 50-year-old White man with noncirrhotic portal hypertension presented with bleeding from gastric varices. Bleeding was initially managed with band ligation and subsequent transjugular intrahepatic portosystemic shunt (TIPS). Over the next few months, the patient had recurrent episodes of anemia, jaundice, fever and polymicrobial bacteremia. Computed tomography (CT) of the abdomen and chest, upper and lower endoscopy, endoscopic retrograde cholangiopancreatography (ERCP), and echocardiography failed to explain the bacteremia and anemia. Follow-up CT scan and Doppler sonography 9 months after placement showed TIPS was occluded. Repeat ERCP showed a bile leak with free run-off of contrast from the left hepatic duct into a vascular structure. The patient's status was upgraded for liver transplantation with Regional Review Board agreement and subsequently received a liver transplant. Gross examination of the native liver demonstrated a fistula between the left bile duct and the middle hepatic vein. Pathologic evaluation confirmed focal necrosis of the left hepatic duct communicating with an occluded TIPS and nodular regenerative hyperplasia consistent with noncirrhotic portal hypertension. Infection is rarely reported in a totally occluded TIPS. Biliary fistulas in patent TIPS have been treated by endoluminal stent graft and endoscopic sphincterotomy with biliary stent placement. Liver transplantation may be the preferred treatment if TIPS becomes infected following its complete occlusion.

Infection of transjugular intrahepatic portosystemic shunt devices: three cases and a review of the literature

During the past decade, transjugular intrahepatic portosystemic shunting (TIPS) has become accepted as an alternative to the surgical shunt procedure for controlling the complications of portal hypertension, yet few data exist regarding infectious complications. The records of all patients who underwent a TIPS procedure during 1992-2000 at a single university teaching hospital were analyzed retrospectively to determine the rate and type of infections that occurred. A search of the English-language literature on the subject was conducted, and the findings were compared with our experience. Three cases of TIPS stent infection were identified out of 180 procedures performed during a 9-year period, resulting in an overall rate of infection of 1.7%. One of the patients was cured, and the other 2 died. A total of 21 cases of TIPS infection were identified from the literature search. A need exists for a standardized case definition for TIPS infection, and one is proposed.

Management of acute variceal haemorrhage

Endoscopic therapy and in particular endoscopic variceal banding ligation, in experienced hands, is the treatment of choice for acute variceal bleeding which remains a major cause of death in patients with cirrhosis and portal hypertension. Pharmacological therapy with Glypressin or somatostatin can be useful to gain time when the endoscopic expertise is not available or to help to obtain a clearer endoscopic view. Transjugular intrahepatic porto-systemic stent shunt is currently used for endoscopic failures, producing similar results with the surgical portacaval shunts. Which one of the two should be preferred, since they both work best in relatively compensated patients, should be a balance between the available surgical and radiological expertise, the urgency of the situation and the expected course of the disease.

Gastric mucosal responses to intrahepatic portosystemic shunting in patients with cirrhosis

BACKGROUND & AIMS

The response of gastric mucosal lesions in cirrhotic patients with portal hypertension, namely, portal hypertensive gastropathy (PHG) and gastric vascular ectasia (GVE), to transjugular intrahepatic portosystemic shunts (TIPS) is not known.

METHODS

Clinical and laboratory evaluation, upper gastrointestinal endoscopy, and Doppler ultrasonography were performed before placement of TIPS and 6 weeks, 3 months, and 6 months after TIPS in 54 patients. Thirty patients had mild PHG, 10 had severe PHG, and 14 had GVE.

RESULTS

Approximately 75% of the patients with severe PHG responded to TIPS as shown by improvement in endoscopic findings and by a decrease in transfusion requirements; 89% of patients with mild PHG had endoscopic resolution. Patients with GVE had neither endoscopic resolution nor a decrease in transfusion requirements after TIPS. There was no difference in mortality between the 2 groups.

CONCLUSIONS

The results support the position that severe PHG and GVE may be different lesions. Mild and severe PHG respond to TIPS. Because GVE does not respond to TIPS, we recommend that TIPS be avoided for the treatment of gastrointestinal bleeding associated with GVE.

Transjugular intrahepatic portosystemic shunts (TIPS): a decade later

Since the introduction of transjugular intrahepatic portosystemic shunt (TIPS) 10 years ago, it has been used increasingly in the management of portal hypertension and its complications. TIPS is now considered the procedure of choice for management of refractory variceal bleeding. Its role in the management of refractory ascites, hepatic hydrothorax, hepatorenal syndrome, and hepatopulmonary syndrome still awaits further prospective studies. The two main complications of TIPS are hepatic encephalopathy and shunt malfunction. Generally, TIPS stenosis or occlusion is a major drawback requiring routine surveillance of TIPS with doppler ultrasound. Venography with balloon dilation of the stent or placement of serial or parallel stents may be required in some cases. Promising modalities of preventing TIPS malfunction (e.g., brachy-therapy, covered stents, or anti-platelet derived growth factor) are currently being investigated.