Congenital malformations in infants of 517 pregestational diabetic mothers

PURPOSE: To explore a method of combined endovascular/conventional treatment of abdominal aortic aneurysm (AAA), in which the iliac arteries are reconstructed by conventional surgical techniques to provide the anatomic substrate for subsequent endovascular repair of the aortic aneurysm. METHOD: A 77-year-old patient with severe cardiac disease was found to have a 6.5-cm AAA, bilateral common iliac artery (CIA) aneurysms, and diffusely narrowed, tortuous external iliac arteries. The left internal iliac artery was occluded. At operation, the right CIA was exposed through a transverse retroperitoneal incision under epidural anesthesia. An iliobifemoral bypass was constructed using a preformed bifurcated graft. A stent-graft was delivered through the right limb of the bifurcated iliobifemoral graft. The proximal end of the stent-graft was implanted in the neck of the aneurysm, and the distal end was deployed in the common trunk of the iliobifemoral graft, thereby excluding the AAA and both native iliac arteries from prograde arterial flow. RESULTS: Completion angiography and follow-up contrast computed tomography showed the aneurysm to be excluded from the circulation. The patient was not intubated, was never hemodynamically unstable, and had aortic blood flow interrupted for no more than 20 seconds. In addition, he was able to resume his usual diet on the first postoperative day. He continues to be well and without evidence of endoleak at 6-month follow-up. CONCLUSIONS: This case demonstrates that iliac artery stenosis, tortuosity, and aneurysmal dilatation are not impediments to endovascular AAA exclusion. Any necessary surgical modifications of pelvic arterial anatomy can be performed before stent-graft insertion to minimize aortic occlusion time.     

Endovascular treatment of abdominal aortic aneurysms. Morphology of aneurysms as one of the deciding indicating factors

Endovascular treatment of aneurysms of the abdominal aorta is based on intravascular bridging of the aneurysm using of an endovascular prosthesis. The prosthesis must be safely anchored above and below the sac of the aneurysm in the non-dilated artery. Therefore the indication of endovascular treatment depends on the morphology of the aneurysm. The objective of the work was to analyse the morphology of the aneurysm with regard to the possibility of endovascular treatment. The morphology of the aneurysm was evaluated with regard to the angiographic examination and examination by computed tomography. The following parameters were investigated: diameter and length of the proximal and distal neck, diameter of the sac in two planes, diameter and tortousity of the iliac arteries, tortousity of the infrarenal aorta. A total of 70 patients with aneurysms of the abdominal aorta were examined. The patients were divided into three groups according to the morphology of the aneurysm. I. infrarenal aneurysms not affecting common iliac artery (n = 20) 28.5%, II. infrarenal aneurysms affecting common iliac artery (n = 38) 54.2%, III. juxtarenal aneurysms regardless of the affection of common iliac arteries (n = 12) 17.1%. Of the total of 70 examined patients 24 (34.2%) with infrarenal aneurysm and 6 (8.57%) with juxtarenal aneurysm were suitable for endovascular treatment.     

Endovascular management of "endoleaks" after transluminal infrarenal abdominal aneurysm repair

PURPOSE: To investigate the reasons for endoleaks after transluminal infrarenal abdominal aneurysm management and the potential for transluminal interventions in subsequent management. METHODS: Prospective analysis of 50 consecutive patients undergoing endovascular aneurysm repair at a single institution with Stentor and Vanguard grafts from March 1995 to March 1997. SETTING: Academic teaching hospital. RESULTS: Two procedures were converted for other reasons than leak. In the remaining 48 successful procedures endoleaks were detected in 11 (22.9%): proximal aortic leak (2.1%), distal aortic leak (8.3%), iliac leak (12.5%). Leaks were treated at the initial procedure in five patients, resulting in 87.5% excluded aneurysms. Twelve and a half per cent were discharged with a primary leak. Redo was performed on all iliac leaks within 7 weeks. All aortic leaks showed spontaneous thrombosis within 3 months, but reappeared with local aneurysm expansion. Aortic redo-procedures were performed by proximal tubular extension or converting a tube graft into a bifurcation graft. All rescue procedures were successful. Secondary leaks have been observed twice in this series, both treated by endovascular means. CONCLUSIONS: Endovascular treatment of primary and secondary endoleaks is possible, and may be a safe alternative to a difficult open procedure.     

Endoleaks after endovascular graft treatment of aortic aneurysms: classification, risk factors, and outcome

PURPOSE: Incomplete endovascular graft exclusion of an abdominal aortic aneurysm results in an endoleak. To better understand the pathogenesis, significance, and fate of endoleaks, we analyzed our experience with endovascular aneurysm repair. METHODS: Between November 1992 and May 1997, 47 aneurysms were treated. In a phase I study, patients received either an endovascular aortoaortic graft (11) or an aortoiliac, femorofemoral graft (8). In phase II, procedures and grafts were modified to include aortofemoral, femorofemoral grafts (28) that were inserted with juxtarenal proximal stents, sutured endovascular distal anastomoses within the femoral artery, and hypogastric artery coil embolization. Endoleaks were detected by arteriogram, computed tomographic scan, or duplex ultrasound. Classification systems to describe anatomic, chronologic, and physiologic endoleak features were developed, and aortic characteristics were correlated with endoleak incidence. RESULTS: Endoleaks were discovered in 11 phase I patients (58%) and only six phase II patients (21%; p < 0.05). Aneurysm neck lengths 2 cm or less increased the incidence of endoleaks (p < 0.05). Although not significant, aneurysms with patent side branches or severe neck calcification had a higher rate of endoleaks than those without these features (47% vs 29% and 57% vs 33%, respectively), and patients with iliac artery occlusive disease had a lower rate of endoleaks than those without occlusive disease (18% vs 42%). Endoleak classifications revealed that most endoleaks were immediate, without outflow, and persistent (71% each), proximal (59%), and had aortic inflow (88%). One patient with a persistent endoleak had aneurysm rupture and died. CONCLUSIONS: Endoleaks complicate a significant number of endovascular abdominal aortic aneurysm repairs and may permit aneurysm growth and rupture. The type of graft used, the technique of graft insertion, and aortic anatomic features all affect the rate of endoleaks. Anatomic, chronologic, and physiologic classifications can facilitate endoleak reporting and improve understanding of their pathogenesis, significance, and fate.     

The fate of the infrarenal aortic neck after open aneurysm surgery

PURPOSE: The long-term success of the endovascular repair of abdominal aortic aneurysms is dependent on the secure fixation of the stent graft at the proximal and distal attachment sites. A progressive dilatation of the infrarenal neck may jeopardize this success. The data regarding this issue are scarce. However, the long-term fate of the infrarenal neck can be studied in patients who have undergone open aneurysm surgery. This was the purpose of the present investigation. METHODS: Between January 1989 and December 1993, 64 patients underwent open repair of infrarenal abdominal aortic aneurysms. Of the 36 patients who were eligible for the study, 19 had preoperative computed tomography scans that were available. The 19 patients also underwent a new computed tomography scanning at a mean of 71 +/- 12 months after surgery. RESULTS: The mean preoperative aortic diameter was 25.4 +/- 3.7 mm at the infrarenal neck, 24.8 +/- 3.4 mm at the level of the renal arteries, and 26.7 +/- 3.0 mm at the level of the superior mesenteric artery (SMA). The mean aortic diameter increased at all of the 3 levels: +2.8 +/- 3.1 mm (P =.0014) at the infrarenal neck, +2.8 +/- 3.0 mm (P =.0013) at the level of the renal arteries, and +1.3 +/- 3.0 mm (P = .080) at the level of the SMA. The annual growth rate was 0.48 mm/y (P = .0023) at the infrarenal neck, 0.46 mm/y (P =.0010) at the level of the renal arteries, and 0.21 mm/y (P = .5811) at the level of the SMA. No correlation was found between the preoperative infrarenal neck diameter (r = .295, P = .2194), the preoperative aortic diameter at the level of the renal arteries (r = .302, P = .2088), and the preoperative aortic diameter at the level of the SMA (r = .314, P =. 2043) and the corresponding growth rates. The patients were stratified into 2 groups one with a small annual growth rate at the infrarenal neck (n = 11; 0.3 mm/y) and no differences in the preoperative infrarenal neck diameter or the clinical characteristics were found between the groups. CONCLUSION: This investigation shows an aortic dilatation of the infrarenal neck and of the aorta at the level of the renal arteries of approximately 0.5 mm annually after open aneurysm surgery. This dilatation raises concern regarding the long-term success after endovascular repair. The data also indicate that 2 populations might exist with regard to the annual growth rate of the infrarenal neck one with low growth rate and one with higher growth rate. This might be of interest for the future selection of patients for endovascular repair.     

Endovascular stent graft repair for aneurysms on the descending thoracic aorta

BACKGROUND: The traditional treatment of aneurysms of the descending thoracic aorta includes posterolateral thoracotomy and aortic replacement with a prosthetic graft. In this study, we report our experiences and results in endovascular stent graft placement as an alternative to surgical repair. METHODS: Between January 1989 and July 1997, a total of 68 patients (24 women) underwent replacement of the thoracic aorta. Mean age at operation was 51 years. Fifty-eight patients underwent conventional surgical treatment. All of these patients were suitable candidates for endovascular stenting; however, no stent graft material was available at the time of operation. Ten patients (1 chronic dissection, 9 atherosclerotic aneurysm) received in the past 8 months the first commercially manufactured endovascular stent graft. The mean diameter of the aneurysms in this group was 7 cm (range, 6 to 8 cm). Two stent patients were operated on using only spinal cord analgesia. All stent grafts were custom designed for each of the 10 patients. RESULTS: The 30-day mortality in the conventional group was 31% versus 10% in the stent group. Mean length of intervention was 320 minutes in the conventional group versus 150 minutes in the endovascular group. Spinal cord injury occurred in 5 patients (12%) in the surgical group, whereas none of the stented patients developed any neurologic sequelae. Mean intensive care unit stay was 13 days, followed by a mean of 10 days on a ward in the first group compared to 4 days in the intensive care unit and 6 days on the ward in the stent group. One stent was required in 2 patients, two stents were required in 3 patients, and four stents were deployed in 5 patients of our series. Five patients required transposition of the left subclavian artery to achieve a sufficient neck for the proximal placement of the stent. There was complete thrombosis of the thoracic aortic aneurysm surrounding the stent graft in 8 patients (80%). Two patients required restenting as a result of leakage (20%). Stent graft placing was performed through the femoral artery in 8 patients, whereas access was only achieved through the abdominal aorta in 2 patients. CONCLUSIONS: These preliminary results demonstrate that endovascular stent graft replacement might be a promising, cheaper, and safe alternative method in selected patients with descending thoracic aneurysms.     

Experience of reoperations followed by repairs of abdominal aortic aneurysms

We experienced 8 cases who required reoperations, including 2 re-redo operations, after repairs of infrarenal abdominal aortic aneurysms. Of 8 patients, one patient developed a new aneurysm due to atherosclerosis in thoraco-abdominal aorta involving all visceral arteries and other 7 patients had aneurysmal formations at proximal anastomotic sites, including 3 suprarenal, 2 juxtarenal and 2 infrarenal aortic lesions. Etiology at initial operation in patients who subsequently developed anastomotic aneurysms included vasculo-Beh?et disease in 4, atherosclerosis in 2 and dissecting aortic aneurysms type III due to Marfan syndrome in 1. At reoperation, all who had vasculo-Beh?et disease had ruptures of anastomotic sites and 2 patients underwent repairs of dehiscent patch, 1 extra-anatomic bypass between ascending and abdominal aorta and 1 interposition of graft. One patient who had graft infection after repair of abdominal aortic aneurysm required axillo-femoral bypass with removal of infected graft. A patient who had dehiscence of proximal anastomosis after repair of aortoiliac occlusive disease required interposition of graft. Two patients, Marfan syndrome and aneurysm in thoraco-abdominal aorta, underwent graft replacement of thoraco-abdominal aorta concomitant with reconstruction of all visceral arteries. There were 8 patients who required reoperations for aneurysms at distal anastomotic sites after repairs of abdominal aortic aneurysms. Five patients underwent repairs of new aneurysms, including replacement of total arch in 3, descending aorta in 1 and iliac artery in 1. In all cases, no hospital death was noted, however, late deaths were occurred in vasculo-Beh?et disease, Marfan syndrome and graft infection. Thus, late result depends on etiology of disease. Although patients who requires reoperation after repair of abdominal aortic aneurysms have higher operative risk factors, early and late results are satisfactory compared to initial operations.     

Clinical results of endovascular stent graft repair for fifty cases of thoracic aortic aneurysms

Between February 1995 and December 1997, 50 cases (55 lesions) of thoracic aortic aneurysms including 20 cases of aortic dissections were treated with an endovascular technique using the stent grafts. All patients were treated in the operating room under general anesthesia and the stent grafts were implanted through 18 Fr. or 20 Fr. sheaths via femoral arteries under fluoroscopic guidance. The stent graft was composed of several units of self-expanding stainless-steel Z stents covered with an ultra-thin polyester fabric. Stent graft deployment was technically successful in 53 of 55 lesions (delivery success rate: 96.4%). Exclusion of the aneurysms and entry closing without endoleak were achieved within two weeks after the operation in 43 of 53 lesions (initial success rate: 81.1%). Endoleak was found in 10 lesions (minor endoleak: 8 and major endoleak: 2 lesions). Two patients died in the periopertive period of delivery failures as injury to external iliac artery and damage to the delivery sheath caused by tortuous and narrow access routes. Endovascular stent graft repair of thoracic aortic aneurysms is minimally invasive operation in comparison with conventional surgical graft replacement with extracorporeal circulation. These early results suggest that the stent graft repair is possibly safe and useful treatment for the patients of thoracic aortic aneurysms especially in high risk patients. However, careful long-term follow-up is necessary to prove the value and the effects of this endovascular treatment and improvement of the stent graft system and technical training of endovascular surgery for operators are required to reduce the delivery failure and to determine the stent graft repair is reliable treatment.     

Anterior patch aortic aneurysm model for the study of endoluminal grafts

Endovascular graft repair for aortic aneurysms has led to concerns regarding the healing characteristics of the graft within a thrombus-lined aneurysm and the effect that collateral flow may have on the endoluminal prosthesis and the aneurysm. An anterior aortic patch aneurysm model that preserved collateral arteries was examined and modified to address these issues. In canines (n = 30) a Dacron knitted patch (n = 27) or a rectus fascia patch (n = 3) was sutured into a 3.5-cm anterior aorotomy. Dacron patch aneurysm diameter was an average of 21.8 +/- 2.2 mm (mean canine normal aortic diameter 9.06 +/- 0.79 mm). Canines underwent angiogram, computed tomography, and/or intravascular ultrasound from 1 to 11 weeks later, at which time an endoluminal prosthesis was deployed and followed 30 to 60 days until harvest. Aneurysms accumulated minimal thrombus through the initial 11 weeks. Significant stenosis (mean 21.2% +/- 19%) occurred at aneurysm necks in association with a patch imbrication suture technique (n = 11). Following modification (n = 16), this decreased to a mean of 3.6 +/- 9.7%. Collateral lumbar artery patency was 95% at the time of imaging prior to graft placement. Following successful graft implantation, 16 of 18 aneurysms were filled with thrombus and in most cases the collateral circulation occluded. One of three fascial patch aneurysms ruptured 21 days after creation. This model more accurately depicts abdominal aortic aneurysms with the inherent thrombus and collateral flow that is important when studying aspects of endovascular aortic graft repair.     

Suppression of heparinization of central venous catheters between cycles of chemotherapy. Results of a phase I study

INTRODUCTION: We investigated the feasibility of the intravascular treatment of iliac aneurysms in patients at high perioperative risk. MATERIAL AND METHODS: January, 1996, to December, 1997, seven iliac aneurysms in 5 patients were treated using endovascular procedures. The patients were 4 men and 1 woman whose mean age was 70 years (range: 61-74 years). Four of 7 aneurysms were in the common iliac artery (2 true aneurysms and 2 anastomotic aneurysms after aortoiliac bypass) and 3 were true internal iliac artery aneurysms. Preoperative CT and arteriography were performed in all cases to define the vascular morphology of the aneurysm, including its exact diameter and length. All procedures were performed in the operating room by a team of vascular radiologists and vascular surgeons, using a portable digital RX system (Philips BV29). The femoral approach was always used, which was percutaneous under local anesthesia in 4 cases and surgical under epidural anesthesia in the other 3 cases, according to the patient's general condition and to common femoral artery morphology. Six endovascular Passager grafts were positioned in the common iliac artery using over-the-wire techniques; platinum coil embolization of the aneurysmatic internal iliac artery had been performed in 2 cases. Coil embolization of the hypogastric artery aneurysm was the only treatment in 1 case. Bilateral aneurysms were treated separately, at intervals of no less than 3 months. RESULTS: Immediate aneurysm exclusion was obtained in all cases, as confirmed at 2-20 months' follow-up in 6 cases. A displaced prosthesis needed reoperation in 1 case. No complications were observed during or early after the procedures, which were always well tolerated by the patients. DISCUSSION: The endovascular treatment of iliac aneurysms is a relatively recent procedure and thus only short- and mid-run results are currently available, which appear satisfactory in 85% of the world's literature cases. Prosthesis displacement and intimal hyperplasia are reported as the main causes of failure. Lacking long-term results, we reserve this method to selected cases. Shorter hospitalization is another advantage. CONCLUSIONS: This little invasive procedure appears suitable for high-risk patients and in the aneurysmatic complications metachronous to surgical bypass.     

Differential effect of unfractionated heparin and low molecular weight heparin on intravascular tissue factor pathway inhibitor: evidence for a difference in antithrombotic action

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.     

Contemporary management of isolated iliac aneurysms

OBJECTIVE: Because isolated common iliac artery aneurysms are infrequent, are difficult to detect and treat, and have traditionally been associated with high operative mortality rates in reported series, we analyzed the outcomes of operative repair of 31 isolated common iliac artery aneurysms in 21 patients to ascertain morbidity and mortality rates with contemporary techniques of repair. METHODS: A retrospective review study was conducted in a university teaching hospital and a Department of Veterans Affairs Medical Center. Perioperative mortality and operative morbidity rates were examined in 17 men and four women with isolated common iliac artery aneurysms between 1984 and 1997. Ages ranged from 38 to 87 years (mean 69 +/- 8 years). Slightly more than half of the cases were symptomatic, with abdominal pain, neurologic, claudicative, genitourinary, or hemodynamic symptoms. One aneurysm had ruptured and one was infected. There was one iliac artery-iliac vein fistula. All aneurysms involved the common iliac artery. Coexistent unilateral or bilateral external iliac aneurysms were present in four patients; there were three accompanying internal iliac aneurysms. Overall, 52% of patients had unilateral aneurysms and 48% had bilateral aneurysms. Aneurysms ranged in maximal diameter from 2.5 to 12 cm (mean 5.6 +/- 2 cm). No patients were unavailable for follow-up, which averaged 5.5 years. RESULTS: Nineteen patients underwent direct operative repair of isolated iliac aneurysms. One patient had placement of an endoluminal covered stent graft; another patient at high risk had percutaneous placement of coils within the aneurysm to occlude it in conjunction with a femorofemoral bypass graft. Patients with bilateral aneurysms underwent aortoiliac or aortofemoral interposition grafts, whereas unilateral aneurysms were managed with local interposition grafts. There were no deaths in the perioperative period. Only one elective operation (5%) resulted in a significant complication, compartment syndrome requiring fasciotomy. The patient treated with the covered stent required femorofemoral bypass when the stent occluded 1 week after the operation. The patient treated with coil occlusion of a large common iliac aneurysm died 2 years later when the aneurysm ruptured. CONCLUSIONS: Isolated iliac artery aneurysms can be managed with much lower mortality and morbidity rates than aneurysm previously been reported by using a systematic operative approach. Percutaneous techniques may be less durable and effective than direct surgical repair.     

Differential expression of heat shock proteins in normal and failing human hearts

OBJECTIVE: To predict spinal cord ischemia after endovascular stent graft repair of descending thoracic aortic aneurysms, temporary interruption of the intercostal arteries (including the aneurysm) was performed by placement of a novel retrievable stent graft (Retriever) in the aorta under evoked spinal cord potential monitoring. METHODS: From February 1995 to October 1997, endovascular stent graft repair of descending thoracic aortic aneurysms was performed in 49 patients after informed consent was obtained. In 16 patients with aneurysms located in the middle and distal segment of the descending aorta, the Retriever was placed temporarily before stent graft deployment. The Retriever consisted of two units of self-expanding zigzag stents connected in tandem with stainless steel struts. Each strut was collected in a bundle fixed to a pushing rod, and the stent framework was lined with an expanded polytetrafluoroethylene sheet. The Retriever was delivered beyond the aneurysm through a sheath and was retracted into the sheath 20 minutes later. A stent graft for permanent use was deployed in patients whose predeployment test results with the Retriever were favorable. Evoked spinal cord potential was monitored throughout placement of the Retriever and stent grafting until the next day. RESULTS: The Retriever was placed in 17 aneurysms in 16 patients. There were no changes in amplitude or latency of evoked spinal cord potential records obtained before or during Retriever placement. After withdrawal of the Retriever, all aneurysms were excluded from circulation immediately after permanent stent grafting. There were no changes in evoked spinal cord potential, nor were neurologic deficits seen after stent graft deployment in any patient. CONCLUSIONS: These results suggest that predeployment testing with the Retriever under evoked spinal cord potential monitoring is promising as a predictor of spinal cord ischemia in candidates for stent graft repair of thoracic aortic aneurysms.     

Endovascular repair of peripheral aneurysms, pseudoaneurysms, and arteriovenous fistulas

Endovascular repair of peripheral arterial lesions was performed in 10 patients including two iliac aneurysms, two iliac anastomotic pseudoaneurysms, one subclavian pseudoaneurysm, one axillary anastomotic disruption, two prosthetic pseudoaneurysms, and two posttraumatic arteriovenous (AV) fistulas. The indications for repair were aneurysm size in five cases, massive hematoma in one, threatened prosthetic dialysis graft in two, venous hypertension with non-healing ulcer in one, and arm pain in one. Vascular access was obtained through surgical cutdown in all cases, via the femoral artery in five patients, the proximal brachial artery in three and a prosthetic graft in two. Stented prosthetic grafts were used in five cases (1 polyester and polytetrafluoroethylene 4 [PTFE]), and PTFE-covered stents in five cases. Concomitant procedures were done in four patients including two open repairs of a common femoral artery aneurysm, a transluminal dilatation of a proximal aortic anastomotic stenosis, and an iliac artery transluminal angioplasty. Eight of 10 cases were technically successful. Completion arteriography revealed complete exclusion of all lesions, except for one minimal proximal stented graft leak in a pseudoaneurysm, and an incomplete obliteration of an AV fistula. No complications occurred. Operative time ranged from 45 min to 5 hours. Postoperative hospital stay was 1 day in five patients, 2 days in three patients, and 4 days in two patients. Follow-up contrast CT scan, arteriography, or duplex scanning demonstrated complete exclusion of all lesions except an AV fistula, and decrease in size in three aneurysms. The proximal leak initially present in a stented graft resolved. All grafts and covered stents remained patent at 2-19 months of followup. Endovascular exclusion of peripheral arterial aneurysms, pseudoaneurysms, and AV fistulas can be done with a high degree of technical success, low morbidity, and short hospital stay. Short-term follow up is encouraging, however, long term follow up of these procedures is warranted to assess durability of the repair and absence of complications.     

Natural history of the residual infrarenal aorta after infrarenal abdominal aortic aneurysm repair

PURPOSE: We determined the natural history of the residual native infrarenal aortic segment after conventional abdominal aortic aneurysm (AAA) repair. METHODS: For the retrospective arteriographic case series, 800 hundred translumbar aortograms (TLAs) were obtained for 272 patients, before and after conventional AAA repair. The main outcome measures were changes in the aortographic diameter and the length of the infrarenal aortic segment, corrected and uncorrected for magnification by normalization to the first lumbar vertebral body height. RESULTS: The mean follow-up time from the preoperative TLA to the most recent postoperative TLA was 42 months (range, 1 to 257 months). Vertebral body height did not change (p = 0.35). The length of the native infrarenal aorta cephalad to the proximal anastomosis increased a mean of 3 mm, from 23 to 26 mm (p = 0.001). However, in 115 patients (43%), this aortic segment elongated more than 5 mm, and in 63 patients (24%), it elongated more than 10 mm. The native residual infrarenal aorta above the proximal anastomosis dilated a mean of 1 mm, from 23 to 24 mm (p = 0.001), but in 21 patients (8%), it dilated more than 5 mm. There was a weak positive correlation between the increase in residual native aortic diameter and duration of follow-up. There was a negative correlation between this increase and the initial size. The diameters of the proximal anastomosis and proximal graft did not change. Marked variability in the changes in aortic dimensions was observed. CONCLUSIONS: A mean period of 42 months after conventional AAA repair, the native infrarenal aortic segment elongates and dilates. Although such enlargement is statistically significant, the average increase appears to be small. However, residual aortic cuff diameter increased more than 5 mm and neck length more than 10 mm in a significant number of patients, with potentially serious implications for endovascular treatment of AAA.     

Regulation of the Wilms'' tumour suppressor (WT1) gene by an antisense RNA: a link with genomic imprinting?

OBJECTIVE: To assess our experience with isolated iliac artery aneurysms and to assess the blood transfusion requirement in patients undergoing surgery for iliac artery aneurysms. MATERIAL AND METHODS: The case records of 12 patients who underwent 12 arterial reconstructive procedures for isolated iliac aneurysms from January 1989 to December 1995 were identified from our prospective vascular database and reviewed. Only patients with aneurysms limited to the common, external, or internal iliac arteries were included. RESULTS: Eleven patients had symptoms and rupture occurred in five patients. Aneurysmorrhaphy with graft interposition was the most common procedure. There was no perioperative mortality. The median transfusion requirement was 11 units per operation (range 1-30 units). The median intraoperative blood loss was 4700 ml (range < 500-13,000 ml). CONCLUSIONS: Isolated iliac aneurysm is a dangerous condition. A low perioperative mortality is possible only if large volumes of blood are available.     

Endovascular grafts for noninfected aortoiliac anastomotic aneurysms

PURPOSE: This report describes our experience with endovascular repair of aortic and iliac anastomotic aneurysms. METHODS: Between June 1994 and March 1996, 12 noninfected aortic or iliac anastomotic aneurysms in 10 patients who had serious comorbid medical conditions that precluded or made difficult standard operative repair were treated using endovascular grafts. No patient in this study had a history of fever, leukocytosis, or computed tomographic evidence of a periprosthetic fluid collection that was suggestive of infection of the original graft. Endovascular grafts composed of polytetrafluoroethylene and balloon-expandable stents were introduced through a femoral arteriotomy and were placed using over-the-wire techniques under C-arm fluoroscopic guidance. RESULTS: Endovascular grafts were successfully inserted in all patients with aortic or iliac anastomotic aneurysms. There were no procedure-related deaths, and complications included one postprocedure wound hematoma and one perioperative myocardial infarction. Graft patency has been maintained for a mean of 16.1 months, with no computed tomographic evidence of aneurysmal enlargement or perigraft leakage. CONCLUSIONS: Endovascular grafts appear to be a safe and effective technique for excluding some noninfected aortoiliac anastomotic aneurysms in high-risk patients and may become a treatment option in all patients who have clinically significant lesions.     

Echolaparoscopic-guided alcohol injection of liver metastases

At Nuremberg Southern Hospital we have been using endovascular therapy for aortic aneurysms for the past 3 years. Between August 1994 and August 1997, 193 patients with infrarenal aortic aneurysms were treated with endovascular stent grafts. Besides using commercially available modular systems of the Stentor type (MinTec/Vanguard*, Boston Scientific) we also participated in a multicenter study implanting EGS devices (EVT in 65 patients). Follow-up examinations must strive to detect thrombotic complications as well as endoleaks with high sensitivity and specificity. To avoid aneurysm rupture significant increase in aneurysm diameter must be detected in a timely fashion to select patients for additional corrective endovascular procedures or conversion to open surgical therapy. A close follow-up regimen therefore is absolutely mandatory for all patients undergoing endovascular aortic grafting, particularly when new prosthetic devices are being introduced. Prosthetic devices that have been adequately tested using controlled study designs and are commercially available may be followed-up using a standardized follow up scheme as delineated. Particularly during the first postoperative year color duplex with use of an intravenous ultrasound enhancing agent has been used successfully to detect even minor endoleaks originating from retrograde perfusion via aortic side branches (lumbar or inferior mesenteric artery). Only patients with documented endoleaks or suspected outflow obstruction requiring further intervention need to undergo diagnostic arteriography. After conventional aneurysm repair yearly duplex scans are usually sufficient to follow the normal patient. Patients who have undergone endovascular therapy, however need to be followed much closer using duplex as well as abdominal CT scans. This will logically result in significantly higher follow up costs. Periinterventional costs of endovascular aortic reconstruction currently exceed those of conventional aortic repair by approximately 50%. Given the current health care finance situation it is questionable whether endovascular therapy of abdominal aneurysm will become standard practice in Germany.     

Results and complications after endovascular reconstruction of aortic aneurysms

Between August 1994 and December 1996 137 patients (10 female and 127 male, mean age 66 yrs., range 27-85) with aortoiliac aneurysmal disease were treated with endovascular stent grafts. Pathology included 5 thoracic, 131 abdominal and 1 isolated iliac artery aneurysm. 88 straight tube grafts (75 Mintec, 12 EVT, 1 Chuter) and 43 bifurcated grafts (21 Mintec, 20 EVT, 2 Chuter) were implanted in the infrarenal aorta. 5 (Mintec) tube grafts were used for the thoracic aneurysms. One tapered tube graft was used to exclude the isolated iliac aneurysm. 11 patients (8%) required conversion to open surgical repair. This was due to defective devices in 5, device related occlusion of a renal artery in 2, aortic dissection in 1, occlusion of iliac outflow in 1, a large unmanageable proximal endoleak in 1 and a retroperitoneal bleeding resulting in hemorrhagic shock in 1 patient. There was one procedure related death for a mortality of 0.7%. Patients were followed every 3-6 months using CT with i.v. contrast and ultrasound duplex examinations with adjunctive usage of an intravenous ultrasound contrast agent (Levovist, Schering AG). Intraarterial DSA was used only when called for by thrombotic or stenotic complications. At a mean follow-up of 9.2 months (range 2-24 months) 16 (17%) primary and 8 (8.5%) secondary leaks (at the distal anchoring zone) were detected after implantation of tube grafts. 11 (25.6%) leaks were detected after implantation of bifurcated grafts. Iliac artery occlusion was observed in 2 patients after placement of a straight endograft, 6 times after reconstruction with a Mintec bifurcated device and 3 times after implantation of an EVT bifurcated endograft. Successful treatment of iliac artery occlusion without the need for subsequent amputation or major disability included extraanatomic bypass in 7 patients, PTA (3 patients) and implantation of wallstents (2 patients) or conservative management (1 patient).     

Genetic therapies for xenotransplantation

PURPOSE: To determine the optimal postoperative imaging modality for the follow-up of patients with endoluminal aortic stent grafts. MATERIAL AND METHODS: From August 1994 to November 1997, 214 patients (194 male and 20 female) with abdominal and thoracic aortic aneurysms were treated with endovascular stent grafts. 137 patients (129 male, 8 female) with 89 tube grafts and 48 bifurcated grafts (45 EVT, 88 Stentor/Vanguard, 3 Chuter, 1 Talent) were evaluated with contrast-enhanced spiral-CT, duplex ultrasound, and DSA at a mean follow-up of 11.1 months. RESULTS: We found 12 persistent primary endoleaks (8.8%), 17 secondary endoleaks (12.4%), 8 limb occlusions (5.8%), 28 endoluminal thrombi lining the stent graft (20.4%), and 26 suture breakages of the stent frame (19%). In 9 patients (6.6%) the proximal end of the stent partially covered the renal arteries. In 3 patients (2.2%) a partial renal infarction was seen. Spiral-CT was able to demonstrate all the above changes except for 3 sidebranch endoleaks that were documented by duplex ultrasound only and 8 suture breaks seen on abdominal plain films only. The median aneurysm diameter decreased from 48 mm pre-operatively to 46 mm at 24 months post-operatively in patients with endoleaks and from 44 mm to 36 mm in patients without endoleak. For several patients the decreasing aneurysm diameter did not reliably correlate with complete exclusion of the aneurysm. CONCLUSION: For follow-up of endoluminal aortic stent grafts contrast-enhanced spiral-CT is superior to duplex ultrasound. DSA is necessary only for patients with complications requiring a secondary intervention.