Richard Waugh

Type III and Type IV Endoleak: Toward a Complete Definition of Blood Flow in the Sac after Endoluminal AAA Repair

In this document the authors continue to refine their seminal categorization of endoleak, a major complication of endovascular aneurysm repair. In addition to type I (related to the graft device itself) and type II (retrograde flow from collateral branches) endoleak, they propose two new categories: endoleak due to fabric tears, graft disconnection, or disintegration would be classified type III, and flow through the graft presumed to be associated with graft wall “porosity” would be categorized as type IV endoleak.

Concurrent comparison of endoluminal versus open repair in the treatment of abdominal aortic aneurysms: Analysis of 303 patients by life table method

PURPOSE The aim of this study was to compare the outcome of consecutive patients with abdominal aortic aneurysm (AAA) treated concurrently by open operation and endoluminal intervention by the same surgeons during a defined interval. METHODS Between May 1992 and May 1996, 362 consecutive patients with AAA underwent repair. Fifty-three patients who underwent open operations for ruptured AAA plus two patients who underwent endoluminal repair of false AAA and four patients who underwent secondary endoluminal repair of AAA were excluded, leaving 303 patients who underwent elective repair of true AAA in the study. The elective operations were conventional open repair (OR) in 195 patients (151 men, 44 women; mean age, 69 years) and endoluminal repair (ER) in 108 patients (100 men, 8 women; mean age, 70 years). The decision to perform ERwas based on comorbidities that precluded open repair (n = 48) and patient choice (n = 60). Graft configuration in the open repair group was tubular (n = 180) and bifurcated (n = 15), and in the ER group tubular (n = 48), aortoiliac/femoral (n = 25), and bifurcated (n = 35). All procedures were performed in the operating department, and radiographic guidance was used in the ER group. Follow-up was by interview, examination, and telephone. In addition, contrast-enhanced computed tomography was performed within the first 10 days after operation, 6 months and 12 months after operation, and then annually thereafter in the ER group. Outcome measures were successful exclusion of the aneurysm sac from the general circulation and survival. Data were analyzed by the life table method. Other outcome measures were length of hospital stay, length of intensive care unit stay, and operative blood loss. RESULTS No significant difference was found between the perioperative mortality rate for OR (11 deaths [5.6%] in 195 patients) and ER (six deaths [5.6%] in 108 patients). Three of the six deaths in the latter group occurred in patients with successful ER, and three occurred in 18 patients with failed ER who were converted to OR. Similarly, no significant difference was seen in the survival rate between the endoluminal and open repair groups when analyzed by the log-rank test (p = 0.14). The rate of graft failure, however, was significantly higher in the ER group than in the OR group (Fishers exact test, p < 0.001). Success in the ER group was defined as continuing graft function without endoleak or conversion to open repair. Kaplan-Meier curve for graft failure times for the endoluminal group revealed a 3-year graft success probability of 70%. CONCLUSIONS This study suggests that ER is safe, sharing the same perioperative mortality risk as OR despite 44% of the ER group being rejected as unfit for OR. Conventional open repair is the most reliable method of successfully managing AAA. The endoluminal method, however, results in shorter length of hospital stay, shorter length of intensive care unit stay, and less blood loss than the open method. Patients who opt for the endoluminal method of repair should be made aware that the minimally invasive technique carries the disadvantage of a higher failure rate.

Transluminal placement of a prosthetic graft-stent device for treatment of subclavian artery aneurysm

A 78-year-old man was seen with an expanding 5 cm false aneurysm of the right subclavian artery. This was treated by an intraluminal graft-stent device introduced through the brachial artery via a 16 F sheath. The graft was constructed from two polytetrafluoroethylene patches of 0.4 mm thickness and anchored in the subclavian artery by an 8 mm stainless steel stent. The procedure was monitored by an image intensifier. Completion arteriography and postoperative duplex scanning confirmed normal flow through the subclavian artery with no communication between the lumen and the aneurysmal sac. The patient recovered without complication.

ISOLATED LIMB INFUSION WITH CYTOTOXIC AGENTS : A SIMPLE ALTERNATIVE TO ISOLATED LIMB PERFUSION

Isolated limb perfusion (ILP) with cytotoxic agents is an effective but complex procedure. Isolated limb infusion (ILI) has been developed as a simpler alternative. Catheters are inserted percutaneously into the axial artery and vein of the affected limb and a pneumatic tourniquet is inflated proximally. Cytotoxic agents are then infused through the arterial catheter and circulated with a syringe for 15 to 20 minutes. Progressive hypoxia occurs, but normothermia is maintained. To date, 175 ILIs have been performed: 164 for melanoma and 11 for other tumours. Results obtained are similar to those obtained by conventional ILP. Morbidity is low and treatment of frail and elderly patients who would not tolerate ILP is possible. An elective double ILI protocol can be used to obtain the additional benefits of fractionated chemotherapy. The possibility of increasing ILI response rates by using other drugs and drug combinations and by multiple fractionated dosing is being investigated.

Treatment of complex abdominal aortic aneurysms by a combination of endoluminal and extraluminal aortofemoral grafts

PURPOSE The purpose of this study was to test the hypothesis that abdominal aortic aneurysms (AAA) whose morphology makes them unsuited for repair with an endoluminal tube graft can be treated by a combination of a transluminally placed aortofemoral graft and a femorofemoral crossover graft. In addition the technique involves either ligation or balloon occlusion of the contralateral common iliac and internal iliac arteries in such a manner that excludes the AAA from the circulation. METHODS We report the use of this technique in three male patients with 6.4 to 7.0 cm diameter AAA. Two had renal impairment and cardiac function too poor to permit open repair, and the third had an unfavorable abdomen caused by previous surgery and the presence of a permanent colostomy. Each patient had an individually tailored Dacron tube graft constructed on the basis of preoperative arteriograms and computed tomography scans. The grafts were delivered transluminally into the aorta through a sheath in the iliac arteries and anchored proximally with a stainless steel stent under radiographic control. The grafts were then anastomosed distally to the femoral artery. RESULTS Recovery was complicated by a midgraft stenosis corrected by percutaneous balloon dilation in one patient, an episode of pulmonary edema in the second and an unexplained pyrexia in the third. Follow-up with duplex scanning confirmed normal flow through the grafts and the presence of thrombus between the prosthetic graft and the aneurysmal sac. CONCLUSIONS We conclude that transluminal placement of an aortofemoral graft combined with a femorofemoral crossover graft is feasible in patients who are unsuited to repair with an endoluminal tube graft. The outcome with this technique is not known and requires further careful evaluation.

Conversion from endoluminal to open repair of abdominal aortic aneurysms: a hazardous procedure.

AIM The purpose of this study was to analyse the technical problems associated with conversion from endoluminal repair of abdominal aortic aneurysms (AAA) to open repair and document the outcome in patients with this clinical course. METHODS Between May 1992 and May 1996 endoluminal repair of AAA was undertaken in 113 patients. Forty-eight of these had medical co-morbidities which led to them being rejected for open repair at other medical centres. Conversion from endoluminal to open repair was required in 18 patients. Thirteen of these occurred at the original operation (primary conversion) and five occurred at a later operation (secondary conversion). Seven of the 18 patients undergoing conversion had serious medical co-morbidities. Three different methods of open repair were used. The technique selected was determined by the cause of failure leading to conversion. Standard open AAA repair was used in patients requiring conversion for access problems (n = 2) and balloon malfunction, where the device ended up entirely within the aneurysmal sac (n = 1). Modifications to the standard technique were required in patients in which the endograft was correctly positioned immediately below the renal arteries and/or where part of the endograft was within one or both common iliac arteries (n = 11). Supra-coeliac control was required for patients with aortic rupture (n = 1), renal arteries covered by the endograft (n = 2) and situations where the delivery catheter was trapped within the aorta above a twisted bifurcated graft (n = 1). The mean volume of contrast used was 225 ml and the mean operative time was 5.25 h in patients undergoing primary conversion. RESULTS Conversion to open repair was achieved in all 18 patients. Renal impairment requiring dialysis occurred in three patients. There were three perioperative deaths, all of which were procedure-related (17%), and one late death. All four deaths occurred from among the group of seven patients with preoperative co-morbidities. CONCLUSIONS Converting an endoluminal to an open AAA repair may require modifications to the standard open technique and result in a much higher than generally accepted morbidity and mortality rate. Patients rejected for open repair because of co-morbidities ran the same chance of requiring conversion as those without co-morbidities (15-17%). If conversion was required, however, they stood a 3 in 7 or 43% chance of dying.

Historic control comparison of outcome for matched groups of patients undergoing endoluminal versus open repair of abdominal aortic aneurysms

PURPOSE Currently no randomized studies show the relative morbidity and mortality of the open and endoluminal methods of abdominal aortic aneurysm (AAA) repair. The aim of this study was to analyze the outcome of two matched groups of patients with AAA, one undergoing open repair and the other undergoing endoluminal repair. METHODS Two groups of patients who had undergone repair of AAA by open technique (group 1) or by endoluminal methods (group 2) were compared. A historic control cohort of 27 patients was selected from 56 consecutive patients who underwent open repair of AAA between January 1991 and February 1992. Patients considered unsuitable for the endoluminal method on the basis of computed tomography and aortography were excluded (n=29). Between May 1992 and November 1994 prospective data were recorded for 62 consecutive patients who underwent endoluminal repair by tube or bifurcated endografts. Twenty-eight patients who had been specifically referred for endoluminal AAA repairs because of preexisting severe medical comorbidities were excluded. Six of the endoluminal cases had failure, requiring conversion to open operation, and were excluded for separate analysis, leaving 28 patients in group 2. Patients in both groups were thus fit and suitable for either open or endoluminal repair and were comparable in relation to age, sex, risk factors, dimensions, and form of AAA. RESULTS The mean values for operation time, blood loss, intensive care stay, and hospital stay for group 1 and group 2 were 2.6 versus 3.1 hours, 1422 versus 873 ml,* 1.8 versus 0.7 days,* and 12.4 versus 11.1 days, respectively (*p<0.05). Local/vascular complications occurred in 15% of patients in group 1 compared with 25% in group 2 (p=0.55), whereas remote/systemic complications occurred in 37% and 29%, respectively (p=0.3). Five of 28 patients in the endoluminal group had complications requiring early operative repair (n=3) or late revision (n=2). When comparison was made on an intention-to-treat basis (with failed procedures included), the incidence of local/vascular complications was significantly greater for endoluminal repair (p=0.047). CONCLUSIONS The incidence of systemic/remote complications was similar for the two groups in spite of significantly less blood loss and shorter intensive care unit stay with endoluminal repair. The incidence of local/vascular complications had a tendency to be higher for endoluminal compared with standard open method (and was significantly greater if failed procedures were included). In this early experience with prototype devices, patients who were medically suitable for open surgical procedures did not derive benefit from the less invasive endoluminal technique with respect to duration of operation, length of hospital stay, or perioperative morbidity and mortality. On the other hand, because they also did not have worse outcome, a randomized study is now justified in this group.

Three-Year Experience with the White-Yu Endovascular GAD Graft for Transluminal Repair of Aortic and Iliac Aneurysms

Purpose: To report a > 3-year experience with a modular, balloon-expandable endovascular graft used for aneurysm exclusion in the aorta and other arteries. Methods: The customized White-Yu Endovascular GAD Graft, a woven polyester prosthesis with an intrinsic Elgiloy wire graft attachment system along the body of the graft, is a flexible endograft design available in straight, tapered, and bifurcated versions that can be delivered transluminally through 18F to 24F sheaths. Results: Since July 1993, 93 patients have received the White-Yu endograft for treatment of 76 abdominal aortic, 3 thoracic aortic, 13 iliac, and 1 popliteal aneurysms. Of the 79 aortic procedures, 39 involved straight tube grafts, 20 were tapered aortoiliac models, and 20 were bifurcated devices. Success rates for tube grafts were 81% in the abdominal aorta and 100% for the thoracic aorta; 5 primary endoleaks (14%) and 2 conversions to surgery (5.6%) occurred with this graft type. Aortoiliac grafts were deployed successfully in 95% (19/20) of cases with 1 conversion (5%) due to thrombosis. Seventy-five percent of the bifurcated endograft procedures were successful, with 4 conversions (20%) for technical failures and 1 graft thrombosis. Four additional endografts were deployed to treat two primary and two secondary endoleaks in tube graft patients. Two access-related arterial injuries were treated surgically. There was one case of embolus to the distal femoral artery but no microembolization. Overall perioperative (30-day) mortality was 3.1%. Over a mean 18-month follow-up (range 2 to 39), no late graft thrombosis, stenosis, or graft migration has been seen on CT scans or X ray. Endoleak has not been detected in any aortoiliac or bifurcated graft. Aneurysm size has diminished consistently in successfully treated cases. Conclusions: The White-Yu endograft appears to offer a safe, efficacious, and minimally invasive means of excluding aneurysms from the circulation. Improvements in patient selection, surgical techniques, and equipment have reduced the incidence of endoleak and conversion to open repair over the course of the evaluation.

A Prospective Study of Changes in Morphology and Dimensions of Abdominal Aortic Aneurysms following Endoluminal Repair: A Preliminary Report

Purpose: The aim of this prospective study was to analyze early changes in morphology and dimensions of abdominal aortic aneurysms (AAA) following endoluminal repair. Methods: Forty-two of 62 patients undergoing endoluminal repair of AAAs between May 1992 and November 1994 were potentially available for follow-up at 6 months or longer after operation. After excluding patients with failed endoluminal repairs, patients who died within 6 months of operation, and patients with anastomotic aneurysms, a study group of 30 patients remained. Contrast-enhanced computed tomography (CE-CT) was performed preoperatively, within 10 days of operation, and at 6 and 12 months postprocedure. Based on the postoperative CE-CT findings, patients were divided into two groups: those with no extravasation of contrast into the aneurysmal sac (group I; n = 26), and those in which there was contrast extravasation (“leak”) into the aneurysmal sac (group II; n = 4). Results: The mean maximum diameters of AAAs in group I diminished progressively at 6 and 12 months, while those in group II increased. Twenty-three (88%) patients in group I had decreased diameter of AAA, while all patients in group II had progressive increase in AAA diameter. Patients who had an increase in AAA diameter had a significantly higher incidence of leak compared with those who had a decrease in diameter (p = 0.001). Conclusions: The majority of AAAs in which the sac has been excluded from the general circulation diminish in size following successful endoluminal repair. An increase in size occurs in those AAAs in which a communication exists between the aortic lumen and the sac. These results suggest that successfully excluded AAAs that continue to increase in size should be suspected of having an undetected leak.

Adverse events after endoluminal repair of abdominal aortic aneurysms: A comparison during two successive periods of time

PURPOSE The aim of this study was to document the incidence rate of adverse events after endoluminal repair of abdominal aortic aneurysms (AAAs) during two successive periods of time. METHODS One hundred ninety patients (175 men, 15 women; mean age, 72 years) underwent endoluminal repair of AAAs in a 5(1/2)-year period. Adverse events were documented prospectively for all the patients throughout this interval. An adverse event was defined as any of the following events: a death within 30 days, a conversion to open repair, the need for further intervention (either open or endovascular), the need for hemodialysis, a failure to cure the AAA, and wound complications. The patients were divided into two groups those who underwent operation in the initial 3-year period (group I; n = 75) and those who underwent operation in the subsequent 2(1/2)-year period (group II; n = 115). The results were analyzed for total adverse events for both periods of time and for difference in incidence rates within categories of adverse events between the two groups. RESULTS Eight patients (4.2%) died in the perioperative period. The endoluminal repair failed in 17 patients (8.9%), which necessitated a primary conversion to open repair at the original operation. In 88 patients, 110 adverse events occurred. There was no significant difference in the incidence rates of adverse events in patients in group I (37/75) and group II (51/115). Apart from primary conversion (P =.007), there was no significant difference in the incidence rates of adverse events between group I and group II within the following categories: perioperative (within 30 days) deaths, primary conversion, secondary conversion, supplementary endoluminal repair, intervention for lower limb ischemia, hemodialysis necessitated, failure to cure the AAA as a result of persistent endoleak, and wound complications. CONCLUSION Despite improvements in technology and increasing experience, adverse events continue to occur in a relatively high proportion of patients (45%) who undergo endoluminal repair of AAA. Reporting the incidence rates of adverse events provides a more accurate picture of the morbidity rates of the endoluminal method rather than simply listing the procedures as successes or failures. The similarity in the incidence rates of adverse events in patients in group I and group II suggests that there are inherent risks in the endoluminal method rather than iatrogenic complications that occur during the learning curve with a new technique.