Reteplase in the treatment of thrombosed hemodialysis grafts.

PURPOSE: To prospectively evaluate the efficacy and safety of reteplase with percutaneous transluminal angioplasty (PTA) in the treatment of thrombosed polytetrafluoroethylene hemodialysis arteriovenous grafts (AVGs). MATERIALS AND METHODS: Forty-two patients were entered into the study. Sixty-two procedures in 43 grafts were performed. One unit of reteplase and 4,000 units of heparin were administered into the AVGs. Routine venography and percutaneous transluminal angioplasty (PTA) was then performed. Patients were transferred for hemodialysis immediately after the procedure. RESULTS: Technical success was achieved in 92% of the cases. Four cases involved intentional repeat thrombosis because of poor outflow and/or need for a new graft site. Minor complications occurred in 6.5% of the cases. No major complications occurred. The mean procedure time for experienced versus less-experienced interventionalists was significantly shorter (P <.001). Primary patency rates were 50%, 34%, and 34% at 30, 90, and 180 days, respectively. CONCLUSION: Reteplase in conjunction with heparin and PTA is a safe and effective means of thrombolysis of AVGs. Its efficacy is comparable to that of other available thrombolytic drugs.

Aortic intimal dehiscence: a complication of percutaneous balloon fenestration for aortic dissection.

A patient with acute type B dissection and a tube configuration of the intimal flap presented with signs of advanced mesenteric and renal ischemia as well as decreased pulses in the lower extremities. The patient was referred for emergency percutaneous fenestration of the abdominal aorta as a salvage procedure and a possible bridge to later surgery. After fenestration, femoral pulses became transiently stronger and then disappeared. The patient died after exploratory laparotomy. Postmortem examination demonstrated dehiscence of the infrarenal abdominal aortic intima with occlusion of the aortic bifurcation.

Balloon-expandable common iliac artery occluder device for endovascular aneurysm repair.

This study was performed to evaluate the efficacy of a balloon-expandable Palmaz stent common iliac artery occluder device for endovascular stent-graft repair of aortoiliac aneurysms. Eighty-four patients (79 men, 5 women; age range 60-95 yr; mean age, 76 yr) with aortoiliac aneurysms underwent endovascular stent-graft repair. The repair consisted of a stent-graft extending from the abdominal aorta to the iliac or common femoral artery, a cross-femoral bypass graft, and an endovascular arterial occluder device within the contralateral common iliac artery. The occluder device consisted of a 5-cm segment of 6-mm diameter polytetrafluoroethylene (PTFE) graft with a purse-string suture occluding the leading end and a Palmaz stent sutured to the trailing end. The occluder device was delivered through a 17F catheter via an arteriotomy. Eighty-three of the 84 patients received aortic endografts. In one case, infrarenal aortic rupture occurred during deployment of the aortic stent requiring conversion to an open surgical repair. Initial technical success for occluder device insertion was achieved in 78 of the remaining 83 patients. Failure to advance the occluder device delivery sheath through a diseased iliac artery occurred in one patient. Common iliac artery rupture occurred during balloon expansion and occluder device deployment in two patients. Two patients required additional coil embolization of the common iliac artery adjacent to the occluder device at the time of stent-graft insertion to correct incomplete iliac occlusion. Delayed occluder device-related complications included one patient with a postoperative iliac endoleak who required percutaneous coil embolization and one patient with a postoperative iliac endoleak in whom a contained aortic aneurysm rupture developed that was treated by surgical ligation of the common iliac artery. Use of the Palmaz stent-based iliac artery occluder device is an effective technique to induce common iliac artery thrombosis to facilitate endoluminal stent-graft aneurysm repair.

Thrombolysis of clotted hemodialysis grafts with tissue-type plasminogen activator.

PURPOSE: To evaluate prospectively the efficacy of treating thrombosed hemodialysis arteriovenous polytetrafluoroethylene (PTFE) grafts using tissue-type plasminogen activator (tPA) and percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: Forty-two sequential thrombosed PTFE dialysis grafts in 33 patients presented for declotting. All 42 grafts were treated with a modified lysis and PTA technique with use of 2 mg tPA and 3,000-5,000 U heparin in a total volume of 5 mL, administered into the graft via an angiocatheter. The elapsed time from tPA injection until completion was recorded. Prospective data collection included demographic information, technical details of the procedure, immediate outcomes, complications, and patency rates. RESULTS: Technical success, defined as complete graft recanalization with a palpable thrill after treatment plus successful hemodialysis, was achieved in all cases, except five. These five cases were deliberate graft closures due to inadequacy of the outflow veins to support an arteriovenous graft after successful lysis. Mean lysis time was 40.8 minutes and mean room procedure time after the lysis period was 65.4 minutes. Eight procedure-related complications occurred (two major and six minor). The follow-up period was 4-241 days, with an estimated mean of 157 days. The 30-day and 90-day primary patency rates were 57% and 50%, respectively. CONCLUSIONS: Treatment of thrombosed PTFE dialysis grafts with use of 2 mg tPA and 3,000 U of heparin is safe and effective. Use of this modified lysis and PTA technique allows an expeditious procedure in the angiography suite. However, this technique precludes imaging of the outflow veins before treatment, so that grafts entering diffusely diseased veins may need to be closed after successful lysis.

Radiology in the diagnosis and therapy of gastrointestinal bleeding.

Major breakthroughs in catheter and guidewire design as well as improvements in angiographic x-ray equipment currently allow interventional radiologists to diagnose massive life-threatening upper and lower GI hemorrhage and to stop the bleeding safely and effectively using superselective catheterization and microcoil embolization. For chronic or recurrent GI bleeding, when endoscopy is unrevealing or equivocal, barium studies, CT scanning, nuclear medicine studies, and angiography can help determine the cause of bleeding. A multidisciplinary approach, including the gastroenterologist, radiologist, and surgeon, is extremely helpful in managing GI bleeding, particularly in high-risk patients or patients presenting as diagnostic dilemmas.

Endovascular grafts in the treatment of thoracic aortic aneurysms and pseudoaneurysms.

The purpose of this study was to describe our experience with balloon and self-expanding endovascular grafts for the management of thoracic aortic lesions. Between February 1997 and June 1998, 20 endovascular grafts were implanted in 14 patients for the treatment of thoracic aortic aneurysms and pseudoaneurysms. Endovascular procedures were performed using one of four different devices: (1) Dacron-covered balloon-expandable Palmaztrade mark stent, (2) balloon-expandable Palmaz stent-PTFE graft prosthesis (BE-PS), (3) self-expanding internally supported Nitinol Dacron prosthesis (Vanguardtrade mark SE-V), and (4) self-expanding externally supported Nitinol PTFE prosthesis (Excludertrade mark SE-E). The results show that endovascular grafting represents a potentially important alternative therapy to open repair of the thoracic aorta. Self-expanding devices were, in our experience, easier to use and more accurately deployed.

Hepatic arterial complications in liver transplant recipients treated with pretransplantation chemoembolization for hepatocellular carcinoma.

PURPOSE: To compare the prevalence of hepatic arterial complications in patients who underwent hepatic arterial chemoembolization for hepatocellular carcinomas before orthotopic liver transplantation with the prevalence of hepatic arterial complications in the total population of liver transplant recipients. MATERIALS AND METHODS: Forty-seven patients underwent selective hepatic arterial chemoinfusion with mitomycin C, doxorubicin hydrochloride, and cisplatin combined with embolization. The prevalence rates for hepatic arterial complications, including pseudoaneurysm, stenosis, anastomotic disruption, and thrombosis, were tabulated and compared with results in 1,154 patients who underwent orthotopic liver transplantation but not chemoembolization. RESULTS: Of the 47 patients who had undergone preoperative hepatic arterial chemotherapy, 13% developed hepatic arterial complications within a mean of 7 days after transplantation; an 8% prevalence of hepatic arterial thrombosis was observed. Of the 1,154 patients who underwent orthotopic liver transplantation but not chemotherapy, 6% developed hepatic arterial complications; a 5% prevalence of hepatic arterial thrombosis was observed. There was no statistically significant difference in the prevalence rates for thrombosis and complications between the patients who underwent chemoembolization before orthotopic liver transplantation and those who did not. The mean interval between chemotherapy and orthotopic liver transplantation was 111 days (range, 3-428 days). CONCLUSION: Patients who undergo hepatic arterial chemotherapy are not at an increased risk of developing hepatic arterial thrombosis or other hepatic arterial complications after orthotopic liver transplantation.

Intraoperative transoesophageal echocardiography as an adjuvant to fluoroscopy during endovascular thoracic aortic repair.

OBJECTIVES: To define the utility of intraoperative transeophageal echocardiography (TEE) during endovascular thoracic aortic repair. DESIGN: Retrospective study. MATERIALS: Five patients underwent six transluminal endovascular stent-graft procedures for repair of thoracic aortic disease. METHODS: After induction of anaesthesia, a multiplane or biplane TEE probe was placed to obtain views of the diseased aorta. Both transverse and longitudinal planes of the aortic arch and descending thoracic aortic segments were imaged. The aortic pathology was confirmed by TEE and the proximal and distal extents of the intrathoracic lesion were defined. Doppler and colour-flow imaging was used to identify flow patterns through the aorta before and after stent-graft deployment. RESULTS: Visualisation and confirmation of the aortic pathology by ultrasonography was accomplished in all patients. TEE was able to confirm proper placement of the endograft relative to the aortic lesion after deployment and was able to confirm exclusion of blood flow into the aneurysm sacs. CONCLUSIONS: TEE may facilitate repair by confirming aortic pathology, identifying endograft placement, assessment of the adequacy of aneurysm sack isolation, as well as dynamic intraoperative cardiac assessment.

Impact of transrenal aortic endograft placement on endovascular graft repair of abdominal aortic aneurysms.

PURPOSE: Successful endovascular repair of an abdominal aortic aneurysm (AAA) requires the creation of a hemostatic seal between the endograft and the underlying aortic wall. A short infrarenal aortic neck may be responsible for incomplete aneurysm exclusion and procedural failure. Sixteen patients who had an endograft positioned completely below the lowest renal artery and 37 patients in whom a porous portion of an endograft attachment system was deliberately placed across the renal arteries were studied to identify if endograft positioning could impact on the occurrence of incomplete aneurysm exclusion. METHODS: Fifty-three patients underwent aortic grafting constructed from a Palmaz balloon expandable stent and an expandable polytetrafluoroethylene (ePTFE) graft implanted in an aorto-ilio-femoral, femoral-femoral configuration. Arteriography, duplex ultrasonography and spiral CT scans were performed in each patient before and after endografting to evaluate for technical success, the presence of endoleaks, and renal artery perfusion. RESULTS: There was no statistically significant difference in patient demography, AAA size, or aortic neck length or diameter between patients who had their endografts placed below or across the renal arteries. However, significantly more proximal aortic endoleaks occurred in those patients with infrarenal endografts (P < or = .05). Median serum creatinine level before and after endografting was not significantly different between the 2 patient subgroups, with the exception of 2 patients who had inadvertent coverage of a single renal orifice by the endograft. Median blood pressure and the requirement for antihypertensive therapy remained the same after transrenal aortic stent grafting. Significant renal artery compromise did not occur after appropriately positioned transrenal stents as shown by means of angiography, CT scanning, and duplex ultrasound scan. Mean follow-up time was 10.3 months (range, 3 to 18 months). Patients who had significant renal artery stenosis (> or =50%) before aortic endografting did not show progression of renal artery stenosis after trans-renal endografting. Two patients with transrenal aortic stent grafts had inadvertent coverage of 1 renal artery by the endograft because of device malpositioning, which resulted in nondialysis dependent renal insufficiency. In addition, evidence of segmental renal artery infarction (<20% of the kidney), which did not result in an apparent change in renal function, was shown by means of follow-up CT scans in 2 patients with transrenal endografts. CONCLUSION: Transrenal aortic endograft fixation using a balloon expandable device in patients with AAAs can result in a significant reduction in the risk of proximal endoleaks. Absolute attention to precise device positioning, coupled with the use of detailed imaging techniques, should reduce the risk of inadvertent renal artery occlusion from malpositioning. Long-term follow-up is essential to determine if there will be late sequelae of transrenal fixation of endografts, which could adversely effect renal perfusion.

Aortoiliac aneurysms: endoluminal repair--clinical evidence for a fully supported stent-graft.

PURPOSE: To evaluate aortoiliac aneurysms repaired with endovascular stent-grafts complicated by hemodynamically significant graft stenosis. MATERIALS AND METHODS: Fifty-four patients (52 men, two women; age range, 41-90 years; mean age, 75 years) with aneurysms of the infrarenal aorta (n = 36) or iliac artery (n = 18) underwent repair by means of placement of an endovascular stent-graft. Technical success was evaluated angiographically during and after placement. At follow-up (range, 12-44 months), all patients underwent sequential duplex ultrasonography, helical computed tomography, and physical examination. RESULTS: Stent-grafts were placed successfully in all cases. Stenosis at the internal iliac arterial origin was identified at angiography in 17 patients (31%). Supplemental intragraft stents were placed in 11 patients, and stent-graft angioplasty alone was performed in one patient. Intragraft stents were placed percutaneously in five patients when stenosis was discovered during follow-up. CONCLUSION: Supplemental intragraft stents were required in 31% of aortoiliac endovascular stent-grafts to correct stent-graft stenosis and preserve long-term function. Placement of a fully supported stent-graft is necessary to repair an aortoiliac aneurysm.

Central venous access: low internal jugular vein approach using imaging guidance.

OBJECTIVE: The use and safety of a low internal jugular vein cannulation technique for central venous access was prospectively evaluated. CONCLUSION: The inferior internal jugular vein provides a safe and direct route to the superior vena cava and right atrium for central venous access. Use of an internal jugular vein cannulation site at the base of the neck avoids kinking of tunneled and untunneled catheters.

Percutaneous renal biopsy complicated by renal capsular artery pseudoaneurysm.

We report a case of renal capsular artery pseudoaneurysm caused by percutaneous renal biopsy. The injury was diagnosed and treated with arteriography and transarterial embolization. Because the arterial injury was extraparenchymal, the clinical manifestations of blood loss were flank pain and decreasing hematocrit without hematuria. Injury to renal capsular arteries during percutaneous renal biopsy is a rare possibility because of their small size.

Obstetric embolotherapy: effect on menses and pregnancy.

PURPOSE: To determine the long-term effects of uterine embolotherapy with gelatin sponge pledgets on menses and fertility. MATERIALS AND METHODS: Between June 1990 and December 1995, 17 women (aged 20-44 years) with obstetric hemorrhage underwent selective gelatin sponge pledget embolization of uterine vessels. Gynecologic information in the 12 women who did not undergo hysterectomy was obtained by means of direct communication or from the patients' physicians. RESULTS: In 11 (92%) of the 12 women, normal menses resumed within 2-5 months of the procedure. There were no complications related to embolotherapy. The follow-up period was 1-6 years. All three patients who desired to conceive had full-term, healthy newborns. The only patient who is amenorrheic is currently receiving medroxyprogesterone acetate; her ultimate menstrual and fertility status cannot yet be determined. CONCLUSION: Selective embolization of the uterine vessels with gelatin sponge pledgets is a safe and effective method of managing pregnancy-related hemorrhage. Our results suggest that women who undergo this procedure can expect to have a return of normal menses with no adverse effect on fertility.