Krassi Ivancev

Distal Migration of Stent-Grafts after Endovascular Repair of Abdominal Aortic Aneurysms

PURPOSE To analyze patients after endovascular repair of abdominal aortic aneurysm (AAA) with respect to distal migration of stent-grafts and its underlying causes. MATERIALS AND METHODS Sixty-five patients underwent endovascular repair between January 1994 and February 1997. There were seven women and 58 men, with a mean age of 71 years (range, 51-84 years). Three patients died in the perioperative period (one of myocardial infarction and two of multiorgan failure) and two patients died within 4 months of the procedure of non-procedure-related causes. In addition, two patients were followed at another hospital. The remaining 58 patients were followed up with spiral computed tomography scans at 1, 3, and 6 months, and biannually thereafter. Angiography was performed at 1 month and 1 year after the procedure and additionally when deemed clinically necessary. Mean follow-up was 29 months (range, 1-49). Migration more than 5 mm was considered significant. RESULTS Twenty-six patients (45%) showed distal migration of stent-grafts during follow-up. Mean follow-up time at detection of migration was 13 months (range, 1-36 months). Thirteen cases of migration were ascribed to dilatation of the proximal aneurysmal neck during follow-up. Ten cases of migration were ascribed to causes other than neck dilatation or poor patient selection. In three cases, no obvious cause for the migration was found. The migration was complete in eight cases, leading to late conversion to open surgical repair. On two of these occasions, complete migration lead to aneurysm rupture. In addition, four patients received additional stent-grafts as proximal extensions. CONCLUSIONS Distal migration of stent-grafts after endovascular AAA repair occurred frequently in this series. Dilatation of the proximal aneurysmal neck is a major cause of distal migration of stent-grafts. Improved proximal fixation is needed to secure long-term durability.

Persistent collateral perfusion of abdominal aortic aneurysm after endovascular repair does not lead to progressive change in aneurysm diameter

PURPOSE To differentiate between the phenomenon of collateral perfusion from a side branch versus graft-related endoleaks after endovascular repair of abdominal aortic aneurysms (AAA), with respect to aneurysm size and prognosis. METHODS We successfully treated 64 AAA patients with endovascular grafting. We followed all the patients postoperatively with spiral computed tomography at one, three, six and 12 months, and biannually thereafter. We measured aneurysm diameters preoperatively and postoperatively. We calculated preoperatively the relation of maximum aortic diameter (D) to the thrombus-free lumen diameter (L) expressed as an L/D ratio. Median follow-up was 15 months. RESULTS Sixteen patients had collateral perfusion during follow-up. We successfully treated two patients with embolization. One patient showed resolution of collateral perfusion after we stopped warfarin treatment. Two patients died of unrelated causes during follow-up. One patient was converted to surgical treatment, and two patients showed spontaneous resolution of their collateral perfusion. The group of patients with perfusion showed no statistically significant change of their aortic diameter on follow-up. The group of patients without perfusion showed a median decrease in aortic diameter of 8mm (p < 0.0001) at 18 months postoperatively. The group of patients with perfusion had significantly less thrombus in their aneurysm sac preoperatively than the group without perfusion, as expressed by the L/D ratio (mean L/D 0,61 versus 0,78, respectively; p=0.0021.) CONCLUSION There was no significant increase in aortic diameter on an average 18 months postoperatively despite persistent collateral perfusion. This may indicate a halted disease progression in the short term. Embolization of collateral vessels is associated with risk of paraplegia. We recommend a conservative approach with close observation if aneurysm diameter is stable.

Treatment of malignant esophageal obstruction with silicone-coated metallic self-expanding stents

Six patients with high-grade malignant esophageal obstruction were treated with silicone-coated metallic self-expanding esophageal stents (Z stents). Endoscopic placement of stents was well tolerated. All patients achieved excellent palliation, defined by a decrease of at least two dysphagia grades, which was sustained. Complications occurred during follow-up in four patients and included stent migration, silicone disruption with tumor ingrowth, food impaction, and perforation (discovered at autopsy) at the distal stent site. Three of the four complications were promptly treated by endoscopic or radiologic intervention. Recent modification in stent design and placement technique will hopefully reduce complications. The self-expanding stent has several theoretical advantages over the rigid plastic stent and Nd:YAG laser for palliation of obstructing esophageal malignancy.

Gianturco-Rösch expandable Z-stents in the treatment of superior vena cava syndrome.

Gianturco-Rösch expandable Z-stents were used in 22 patients with superior vena cava syndrome (SVCS). Stents were placed in all patients in the SVC and in 17 patients, also into the innominate veins. Stent placement resulted in complete relief of symptoms in all patients. Twenty-one patients had no SVCS recurrence from 1 to 16 months, to their death, or to the present time. SVCS recurred only in 1 patient 9 months after stent placement due to tumor ingrowth and secondary thrombosis. Based on ours and on other reported experiences, expandable metallic stents are effective devices for treatment of the SVCS which is difficult to manage by other means.

Endovascular repair of ruptured abdominal aortic aneurysms: logistics and short-term results.

PURPOSE To report our experience in establishing a treatment protocol for endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (rAAA), including an investigation of the reasons for patient exclusion and a report of our short-term results. METHODS Between 1997 and July 2002, 21 patients with rAAA underwent endovascular repair according to our protocol and were followed prospectively. A retrospective analysis was also conducted of 23 rAAA patients treated with open repair from January 2001 through June 2002. Procedural and clinical data from this sample were compared to 14 contemporaneous emergent EVAR cases and analyzed to determine why the open repair patients were not treated with an endovascular approach. RESULTS Among the 21 patients treated with emergent EVAR since the beginning of this protocol, 6 (29%) procedures were performed under local anesthesia and 6 were performed percutaneously. Thirty-day mortality was 19%. In the comparison of 14 emergent EVAR cases to 23 open rAAA repairs, the mean duration of symptoms prior to intervention was 12 hours for the EVAR patients and <1 hour for OR patients. No significant difference was found in operating time, but the EVAR group had significantly less blood loss (p=0.0001) and transfusion needs (p=0.02); duration of intensive care unit stay was significantly shorter in the EVAR group (p=0.02). Thirty-day mortality was 29% (4/14) for EVAR and 35% for OR (8/23) (p>0.05). Reasons for not performing EVAR were unavailability of adequate equipment (n=11) or trained staff (n=7), hemodynamically unstable patient (n=2), mycotic aneurysm (n=2), and unfavorable anatomy in a 60-year old patient with a <5-mm-long, sharply angled infrarenal neck. CONCLUSIONS Endovascular repair of ruptured aortic aneurysms is feasible, and short-term results are promising. Good logistics, adequate training of physicians and staff in an elective setting, and versatile endografts are prerequisites for this type of treatment program.

Management of biliary complications after liver transplantation

Biliary tract complications after liver transplantation are common, and the evaluation of newer treatment options compared with standard surgical treatment is important. In 62 liver transplants performed in 55 adult patients, the biliary tract was reconstructed with choledochocholedochostomy (CC) in 52 (84%) and Roux-en-Y choledochojejunostomy (RYCJ) in 10 (16%). Seventeen biliary tract complications occurred in 16 patients (29%). The incidence of complications was the same after CC and RYCJ. Eight complications (47%) occurred within the first month and nine (53%) thereafter. Only 6 of 17 (35%) biliary tract complications required operation. One patient died of a biliary tract complication. No other allografts were lost due to biliary tract complications. Four patients transplanted at other centers were also treated, for a total of 21 biliary tract complications. Overall, there were nine bile leaks, eight bile duct strictures, two Roux loop hemorrhages, one choledocholithiasis, and one ampullary dyskinesia. Temporary or permanent stents were used successfully in seven of eight strictures. Five bile leaks were managed without operation. Nonsurgical management is appropriate for a selected majority of patients with late bile leaks, biliary tract strictures, or choledocholithiasis after liver transplantation.

Abdominal aortic aneurysms: experience with the Ivancev-Malmo endovascular system for aortomonoiliac stent-grafts

PURPOSE To describe a component-based aortomonoiliac stent-graft system and the first clinical results achieved with this device in endovascular abdominal aortic aneurysm (AAA) repair. METHODS From November 1993 to October 1996, 45 patients aged 60 to 86 years underwent endoluminal exclusion of true AAAs (median diameter 60 mm) involving the common iliac arteries (median diameter 16 mm right and 15 mm left) using unilimb stent-grafts deployed with the Iancev-Malmö system. RESULTS Six immediate conversions occurred in the beginning of the series due to endografts that were too short. Complications, including 2 inadvertent renal artery occlusions, 7 kinked grafts, 6 iliac artery dissections, and 3 perioccluder leaks, were prominent features in the first 15 patients. Five patients died in the postoperative period, four of whom were nonsurgical candidates. There were five significant stent-graft migrations: one 3 weeks after surgery due to mechanical injury of the proximal stent and four after 1 year owing to continuous dilation of a wide proximal neck, stent-graft placement in a conical, thrombus-lined proximal neck, and two instances of proximal extension separation from the main graft. Translumbar aneurysm perfusion required embolization in 3 patients. CONCLUSIONS Despite early complications associated with a learning curve, exclusion of large AAAs using unilimb stent-grafts is feasible. Strict inclusion criteria are necessary in order to improve mortality among nonsurgical candidates and minimize the risk for late migration.

Global experience with an inner branched arch endograft.

BACKGROUND Branched endografts are a new option to treat arch aneurysm in high-risk patients. METHODS AND RESULTS We performed a retrospective multicenter analysis of all patients with arch aneurysms treated with a new branched endograft designed with 2 inner branches to perfuse the supra aortic trunks. Thirty-eight patients were included. The median age was 71 years (range, 64-74 years). An American Society of Anesthesiologists score of 3 or 4 was reported in 89.5% (95% confidence interval [CI], 79.7-99.3) of patients. The 30-day mortality rate was 13.2% (95% CI, 2.2-24.2). Technical success was obtained in 32 patients (84.2% [95% CI, 72.4-95.9]). Early secondary procedures were performed in 4 patients (10.5% [95% CI, 0.7-20.3]). Early cerebrovascular complications were diagnosed in 6 patients (15.8% [95% CI, 4.0-27.6]), including 4 transient ischemic attacks, 1 stroke, and 1 subarachnoid hemorrhage. The median follow-up was 12 months (range, 6-12 months). During follow-up, no aneurysm-related death was detected. Secondary procedures during follow-up were performed in 3 patients (9.1% [95% CI, 0.0-19.1]), including 1 conversion to open surgery. We compared the first 10 patients (early experience group) with the subsequent 28 patients. Intraoperative complications and secondary procedures were significantly higher in the early experience group. Although not statistically significant, the early mortality was higher in the early experience group (30% [95% CI, 0.0-60.0]) versus the remainder (7.1% [95% CI, 0.0-16.9]; P=.066). Being part of the early experience group and ascending aortic diameter≥38 mm were found to be associated to higher rates of combined early mortality and neurologic complications. CONCLUSIONS Our preliminary study confirms the feasibility and safety of the endovascular repair of arch aneurysms in selected patients who may not have other conventional options. CLINICAL TRIAL REGISTRATION INFORMATION Thoracic IDE NCT00583817, FDA IDE# 000101.

Renal arteries covered by aortic stents: clinical experience from endovascular grafting of aortic aneurysms

OBJECTIVES During the endovascular repair of abdominal aortic aneurysms (AAAs), effective anchoring of the stent-graft is difficult in the presence of a short infrarenal aneurysm neck. The aim of this study was to investigate renal artery patency and renal function after deployment of graft anchoring stents across the renal arteries. DESIGN Retrospective open study. PATIENTS Twenty-five renal arteries, in 18 patients treated by endovascular exclusion of an AAA, were intentionally covered with the Gianturco Z-stent to ensure stent graft attachment. METHODS Renal artery patency was assessed by repeated spiral computed tomography (CT) scans and angiography. Creatinine levels, blood pressure and antihypertensive medication were recorded. Follow-up was a median 6 months (2-9). RESULTS All 25 stent-covered renal arteries remained patent. CT showed a small infarct in one kidney. Creatinine was 108 mumol/l (89-133) before intervention and 98 mumol/l (87-127) at follow-up. Blood pressure was 150/80 mmHg on both occasions. Antihypertensive therapy was intensified in one patient whose creatinine level remained stable and whose separate renin sampling was normal. CONCLUSIONS Covering the renal arteries with the Gianturco Z-stent does not seem to affect renal function within 6 months. Further follow-up is needed before suprarenal stent deployment can be advocated.

Effective palliative treatment of metastatic carcinoid tumors with intra-arterial chemotherapy/chemoembolization combined with octreotide acetate

Survival in patients with metastatic carcinoid tumors is dependent on control of tumor growth and adequate palliation of vasoactive amine-induced symptoms of flushing, diarrhea, wheezing, and valvular heart disease. Eight patients with carcinoid tumors metastatic to the liver were treated with long-term octreotide acetate therapy (100 to 500 micrograms three times a day), intra-arterial 5-fluorouracil infusion (2 g/day x 5 days), and hepatic tumor chemoembolization. All eight patients became asymptomatic and have remained so with a mean follow-up duration of 22 months from the time of first infusion. Following institution of subcutaneous octreotide acetate, intra-arterial infusion, and tumor chemoembolization, all patients are alive with a mean survival of 40 months from the time of diagnosis of carcinoid syndrome (range: 2 to 108 months). Four patients had greater than a 50% decrease in tumor size after therapy (mean follow-up duration: 10.6 months), and the other four patients have had stable disease after institution of therapy. It appears that combinations of long-term subcutaneous administration of octreotide acetate, intra-arterial 5-fluorouracil, and tumor chemoembolization effectively control progressive liver metastasis and provide excellent symptomatic palliation in patients with hepatic metastasis from functional carcinoid tumors.