Endoluminal Repair Research Articles

Intermediate to Long-term Outcomes of Endoluminal Stent-Graft Repair in Patients With Chronic Type B Aortic Dissection

To assess mid- to long-term clinical results of stent-graft repair in patients with type B aortic dissection. Retrospective analysis was done on 72 patients (47 men; mean age 55+/-12 years) who were diagnosed with chronic type B aortic dissection and underwent stent-graft repair from June 1994 to December 2007. Two types of stent-grafts were employed. Prior to 2000, a custom-designed stent-graft composed of self-expanding Z-type stainless steel stents covered with woven polytetrafluoroethylene material was used. Thereafter, a separate-type (modular) manufactured stent-graft was used, consisting of proximal and distal nitinol stents with an unsupported Dacron tube graft in between; the unsupported graft was stented after deployment. Procedural success (completion of the stent-graft deployment at the target area without device failure) was obtained in 97% (70/72). The 2 failures were due to stent migration and tortuous anatomy, respectively. There were persistent type I endoleaks in 6 cases for a clinical success (entry tear exclusion) of 88% (64/72). There was no immediate postprocedural mortality or paraplegia. There was unintended partial left subclavian artery occlusion in 1 case, as well as postprocedural transient renal failure in 1 patient and 2 access-site pseudoaneurysms. Median follow-up was 43 months (range 5-97, mean 64.4+/-38.8) in 61 patients (3 patients lost to follow-up). Five patients died, 1 of probable aortic rupture in the setting of residual type I endoleak. Overall clinical success (no death, conversion, or endoleak) was achieved in 84% (47/56); of these, 35 (74%) showed complete resolution of the thoracic false lumen, while the other 12 (26%) had a decrease in false lumen diameter. Intermediate to long-term results of stent-graft implantation in patients with chronic type B aortic dissection seem acceptable and may justify the use of this minimally invasive approach as first line therapy in these patients.

Abstract No. 211: Featured Abstract

The assumption exists that endoluminal aneurysm repair has a higher rate of secondary interventions compared to open surgery. This has led to an unchallenged requirement for long-term interval surveillance and concerns over long-term cost-effectiveness. We examine our experience of over 400 procedures to assess the validity of these assumptions.

Technique for subclavian to carotid transposition, tips, and tricks

When performed properly, a transposition is the most efficient and most durable procedure for reconstructing the subclavian artery for proximal occlusive disease or to extend the landing zone in the aortic arch prior to endovascular therapy for thoracic aortic pathology. The proximal subclavian artery, on the right or on the left, is approached quite differently than it is for a bypass procedure. The technique is described in detail here. There are very few contraindications to transposition, the advantages over the alternate options are many, and it can be the approach of choice in the vast majority of patients.

Endovascular versus open repair for descending thoracic aortic rupture: institutional experience and meta-analysis

Rupture of thoracic aneurysm, acute type B dissection, blunt thoracic trauma, and penetrating aortic ulcer can present with a similar clinical profile of thoracic aortic rupture. We report a meta-analysis of comparative studies evaluating endoluminal graft versus open repair of these lesions as well as the early experience from our institution. We searched the following databases for reports of endovascular versus open repair of acute descending thoracic aortic rupture: Medline/PubMed, OVID, EMBASE, CINAHL, ClinicalTrials.gov, the Cochrane central register of controlled trials and the Cochrane database of systematic reviews. We used the random-effects model to calculate the odds ratio (OR) and 95% confidence intervals (CI) for mortality, paraplegia/paraparesis and stroke rates. Also, the medical records of the patients treated in our institution with this technique from 2000 to 2008 were reviewed. Demographics, comorbidities and operative procedure information were retrieved. Outcomes examined were mortality, paraplegia and stroke. Meta-analysis indicates that endoluminal graft repair is accompanied by lower procedure related mortality (OR 0.46, 95% CI 0.26-0.78, p=0.005) and paraplegia rates (OR 0.23, 95% CI 0.08-0.65, p=0.005), as compared to open repair. There was no difference in stroke rate between the two methods (OR 0.86, 95% CI 0.26-2.8, p=0.8). We have treated 13 patients with endoluminal stent-grafts. No conversion to open repair was necessary. Stroke rate was 15%, no patient died as a result of the stent-graft placement, one patient died as a result of massive head injury (overall 30-day mortality: 7.5%). There were no spinal cord ischemic complications. Our experience and meta-analysis indicate that thoracic endograft repair has low mortality and spinal cord complication rates for treatment of acute thoracic aortic rupture. If this method proves to be durable, it could replace open repair as the treatment of choice for these critically ill patients.

Intracranial Pseudoaneurysms, Fusiform Aneurysms and Carotid-Cavernous Fistulas

The study assessed the effectiveness and safety of endovascular covered stents in the management of intracranial pseudoaneurysms, fusiform aneurysms and direct carotid-cavernous fistulas. Fourteen endovascular covered stents were used to repair three pseudoaneurysms, six fusiform aneurysms and six direct carotid-cavernous fistulas. Aneurysms were in the carotid artery in seven cases, in the vertebral artery two cases. It was not possible to treat two additional cases transcutaneously for technical reasons (2/15). Percutaneous closure of the lesions with an endovascular covered stent was successful in 13 of 15 cases. Initial follow-up showed good stent patency. No complications were observed after stent implantation. During follow-up, stent thromboses were detected in two of nine patients with follow-up digital subtracted angiography. One carotid-cavernous fistula of Barrow Type A transformed into Barrow Type D at nine month follow-up study was cured with a procudure of Onyx-18 injection. Endovascular covered stents may be an option for percutaneous closure of intracranial pseudoaneurysms, fusiform aneurysms and direct carotid-cavernous fistulas. Endoluminal vascular repair with covered stents offers an alternative therapeutic approach to conventional modalities.

Educational challenges in vascular surgery: An Australasian response

In Australia and New Zealand, training requirements in vascular surgery have substantially changed since 2002. Training in general surgery is no longer required. Trainees in vascular surgery need to be competent in open vascular surgery and in performing and interpreting vascular ultrasound imaging. They must also master a full range of endovascular procedures, including cannulation of arteries, and angioplasty and stenting procedures, and endoluminal repair of aneurysms with stent grafting. Applicants complete a rigorous selection process and are ranked nationally. Training is started in postgraduate year 3 or at any time beyond that. The 5-year program is the competency-based surgical education training (SET) program. The trainees sit an examination at the end of the SET 1 and also an exit examination in SET 5. Before the final examination, the trainees must have performed 400 major cases as primary operators and 150 peripheral percutaneous interventions. In addition they must satisfy the requirements of the on-line in-service examinations and show adequate ultrasound case volumes and completion of research projects.

Laser-welded endoscopic endoluminal repair of iatrogenic esophageal perforation: An animal model

To test the feasibility of laser tissue welding (LTW) in creating an endoscopic transluminal repair of esophageal perforation. Animal model. A diode laser was used to create an endoluminal rabbit esophageal perforation repair. Burst pressures were compared with open incision, external suture, and external laser-augmented suture closure. Comparisons were performed five times and analyzed with Kruskal-Wallis analysis of variance and a post hoc Dunn method. The burst threshold of the endoluminal weld (54.78 +/- 5.84 mm Hg) was significantly higher than that of the open incision (6.5 +/- 1.94 mm Hg) and not significantly different than that of the external suture (37.18 +/- 1.97 mm Hg) or the laser-augmented suture group (71.60 +/- 7.58 mm Hg). Laser welding is a feasible method of creating endoluminal repairs with burst strengths comparable with external suture repair, which may allow a subset of patients to avoid traditional open approaches. This is the first reported animal model of LTW for endoscopic closure of iatrogenic esophageal perforation.

Endovascular Repair of Extracranial Carotid Artery Dissection: Current Status and Level of Evidence

To provide evidence for the endovascular repair of patients with extracranial carotid artery dissection. A comprehensive literature review was performed whereby all studies that reported on the results of endoluminal repair of extracranial carotid artery dissection and provided information about primary technical and clinical success were identified. The Pubmed, Embase, and Medline databases were searched between January 1997 and February 2008 by two independent observers by using combinations of search terms "endovascular repair," "extracranial carotid artery," and "carotid dissection." After studies were selected according to the given criteria, 13 studies were included in our statistical analysis. The number of reported patients was 62, with a total of 63 extracranial carotid artery dissections. The mean patient age was 43.3 years. The mean follow-up period was 15.7 months +/- 8.7. Various causes were responsible for the disease, including a blunt neck injury in 28 patients (45%), spontaneous dissection in 21 (37%), and iatrogenic trauma during invasive radiologic procedure in 17.7% patients. The technical success rate was 100% (63 of 63 procedures). The primary and 1-year patency rate of the stents and/or stent-grafts was 100%. The overall major adverse cardiovascular events rate was 11% (seven strokes). The total follow-up mortality rate was 0%. The current status of the reported cases in the literature regarding the treatment of carotid artery dissection by means of stent placement shows excellent early and 1-year patency rates and a low major adverse cardiovascular event rate. However, further evaluation is necessary to draw robust conclusions.

Endoluminal Stent-Graft Repair in a Patient With Coarctation of the Aorta and Previous Iatrogenic Type B Aortic Dissection and Expanding Pseudoaneurysm

To report endoluminal repair of aortic coarctation in a patient with a chronic type B aortic dissection presenting with an expanding pseudoaneurysm after failure of surgical repair. This 30-year-old man with a congenital coarctation of the aorta suffered an iatrogenic type B aortic dissection during angiography at the age of 6. Emergent surgery at that time included a left subclavian artery-to-distal thoracic aorta surgical conduit; the coarctation itself was not repaired. The patient presented 24 years after the surgery with a chronic distal extension of the dissection and a pseudoaneurysm severely compressing the aortic true lumen; the disrupted surgical conduit drained into the false lumen. In a novel approach, the true aortic lumen was intentionally occluded, and the surgical conduit was secured with stent-grafts to successfully exclude the pseudoaneurysm from the circulation. Type B dissection and coarctation of the aorta, in the setting of complex aortic pathology and comorbidities, can be treated with an endovascular approach.

The Risks of Celiac Artery Coverage During Endoluminal Repair of Thoracic and Thoracoabdominal Aortic Aneurysms

The risks of purposeful celiac artery coverage during endovascular thoracic aortic aneurysm repair (TEVAR) to obtain an adequate distal landing zone have received scant scientific attention. Patients undergoing TEVAR at 6 tertiary centers from January 2000 to June 2007 were identified (n = 434); cases requiring celiac artery exclusion (n = 19; 4.4% of the total) were analyzed. The mean follow-up was 8.7 months (range, 0.2-21.2). The mean patients' age was 73.6 years (range, 56-86); 57.9% were men. The mean aneurysm diameter was 6.7 cm (range, 5-8.6). In 2 patients, the celiac artery balloon occlusion test was performed prior to TEVAR. In both, intact collateral foregut circulation was seen. Both underwent TEVAR without celiac artery revascularization; 1 did well, whereas the other developed foregut ischemia. In 16 cases (84.2%), the celiac artery was not revascularized prior to TEVAR. In those patients, 19 complications were reported (3 deaths; 2 paraplegia). No similar events occurred in those who underwent celiac artery revascularization (n = 3). Celiac artery coverage during TEVAR is required in 4.4% of cases. TEVAR correlated with a nonnegligible number of major complications. Complications were more frequent and severe in patients who did not have celiac artery revascularization prior to TEVAR. Specific celiac artery coverage complications are rare and not readily predictable based on preprocedure arteriography.

R405 – Laser Welded Transluminal Repair of Rabbit Esophageal Injury

Problem To test the feasibility of Laser Tissue Welding in creating an endoscopic transluminal repair of esophageal perforation. Methods A diode laser was used to create an endoluminal rabbit esophageal perforation repair. Burst pressures were compared to open incision, external suture, and external laser augmented suture closure. Comparisons were performed 5 times and analyzed using Kruskal-Wallis ANOVA and a post-hoc Dunn's Method. Results The burst threshold of the endoluminal weld (54.78mHg) was significantly higher than the open incision (6.5mmHg) and not significantly different than the external suture (37.18mmHg) or the laser augmented suture group (71.60mmHg). Conclusion Laser welding is a feasible method of creating endoluminal repairs with burst strengths comparable to external suture repair. Significance This is the first report of Laser Tissue Welding for endoscopic closure of iatrogenic esophageal perforation which may allow a subset of these patients to avoid traditional open approaches.

A randomized, placebo-controlled trial of doxycycline after endoluminal aneurysm repair

The late durability of endovascular aneurysm repair (EVAR) has been limited by progressive aortic degeneration believed to be mediated by matrix metalloproteases (MMP). The goal of this study was to evaluate the effect of a MMP inhibitor, doxycycline, on EVAR. Patients undergoing EVAR were randomized to doxycycline (100 mg twice daily) or placebo for 6 months following the procedure. Clinical data, blood samples, and computed tomography (CT) scans were obtained preoperatively, postoperatively (blood only), and at 1- and 6-month follow-up. Forty-four subjects were analyzed based on intention-to-treat. Plasma MMP-9 decreased significantly below baseline in the doxycycline (N = 20) treated patients at 6 months (-16.4% +/- 20.7%, P < .05) while there was a nonsignificant increase in the placebo (N = 24) group (128.1% +/- 73.5%). This was primarily related to changes between 1 and 6 months. In patients with endoleaks at 6 months, plasma MMP-9 increased in 83% of the placebo treated patients, but in only 14% of the doxycycline treated group (P < .03). Among endoleak-free patients with AneuRx or Excluder endografts, doxycycline treatment resulted in greater decreases in maximum aortic diameter than placebo treatment (-13.3% +/- 3.3% vs -3.8% +/- 3.0%, P < .05). Furthermore, doxycycline treatment significantly reduced the aortic neck dilatation at 6 months in Excluder treated patients. There is evidence of persistent MMP release representing ongoing aortic degradation after endografting which can be inhibited by doxycycline therapy. In analyses based on the endograft used, treatment with doxycycline also demonstrated evidence of increased aortic dimensional stability, a surrogate marker for long-term success of EVAR. Although encouraging, these results require confirmation in larger patient populations. Doxycycline should undergo more thorough evaluation as a potential adjuvant treatment to improve the results of EVAR, particularly in certain subgroups.

Endoluminal Repair of a Pseudoaneurysm in a Patient with Cryopreserved Arterial Allograft of the Iliac Vessel

Prosthetic infection is one of the most serious complications of vascular surgery, and its treatment remains a surgical challenge. Good results have been reported using in situ replacement with arterial allografts, but late degeneration of the graft itself may necessitate further repair. We report a case of rupture and pseudoaneurysm formation of an iliac artery homograft urgently treated by endoluminal grafting with complete and immediate exclusion of the sac without complications. At 6-month follow-up angio-computed tomography showed patency of the vascular stent graft without leak evidence. Two years and 6 months after the procedure, the patient is well and alive.

Retrograde type A dissection after endovascular stenting of the descending thoracic aorta. Is the risk real?☆

Retrograde type A dissection during or after endoluminal graft repair of the descending thoracic aorta is a potentially lethal complication unique to thoracic endografting. Our aim is to increase its awareness and to review possible etiological factors. Two hundred and eighty-seven patients with different thoracic aortic pathologies were treated with endovascular prostheses over the last 6 years (February 2000 to March 2006) under a single-site protocol. A retrospective review was conducted to identify any retrograde aortic dissections by both chart and film review. Factors that may have contributed to its formation were also documented. This population was analyzed for the complication of retrograde aortic dissection as well as the factors related to its occurrence. Seven patients (2.4%) with a gender distribution of three males and four females experienced a retrograde type A dissection within this sample at a median of 202 days. The mean age was 74 years (range 53-83). Aortic pathologies included aortic dissections (n=6) and thoracic aortic aneurysm (n=1). There were (n=3) 43% retrograde type A dissections identified within the perioperative period. Balloon angioplasty was performed in 71.4% (n=5). Two female patients (28.6%) had this event identified within their initial hospitalization with fatal consequences. Overall mortality was 57% (n=4) with extension of dissection the primary cause of death n=3 and open surgical repair (n=1) after an extension of retrograde dissection. Female gender, use of stent-grafts for dissection and possible aggressive balloon angioplasty may play a role in the cause of retrograde type A dissection. A close surveillance program is recommended when using thoracic endografts outside the recommended device instructions for use.

Endovascular infrarenal abdominal aortic aneurysm repair

Abdominal aortic aneurysm repair has undergone a revolution since Volodos and Parodi described endoluminal repair in the early 1990s. Subsequent data from large registries have confirmed its efficacy. Randomised controlled...

Utility of left subclavian artery revascularization in association with endoluminal repair of acute and chronic thoracic aortic pathology

Utility of left subclavian artery revascularization in association with endoluminal repair of acute and chronic thoracic aortic pathology

Endoclipping of iatrogenic colonic perforation to avoid surgery

Colonoscopy is an established tool for the diagnosis and management of colonic and rectal pathology. Even though colonic perforation is rare after colonoscopy, it is a serious and typical complication. The definitive management remains controversial. Both operative and nonoperative techniques have been described in the literature, though the standard treatment for these patients is still an operative repair of the perforation site. Recently, endoscopic clip application was recommended, particularly for iatrogenic perforations, but less is known about the effectiveness of endoluminal repair of colonic perforations with clips. In this series, 7589 colonoscopies were performed over a 34-month period in a tertiary-level referral center. Three perforations occurred during 5413 diagnostic colonoscopies. Therapeutic colonoscopy was under taken in 2176 patients, resulting in a total of 27 perforations. Out of 30 patients with colonic perforation, five patients underwent operative management and 25 patients were subsequently treated nonoperatively. In 27 patients, endoscopic application of inert metallic clips was used for closure of iatrogenic perforation. Twenty-five of these patients were treated non-operatively, while two patients underwent surgery. The mean postoperative length of hospitalization for patients was 12.2 days, compared to 3.5 days for patients treated conservatively. Endoluminal repair of colonic perforations with clips and further conservative treatment seems to provide a tool that avoids the major additional trauma associated with laparotomy or laparoscopy and minimizes the length of hospitalization.

Vascular Graft Replacement of the Ascending and Descending Aorta: Do Dacron Grafts Grow?

The tendency of Dacron vascular grafts to expand after placement in the ascending and descending thoracic aorta has been noted, but never described in detail. From 1986 to 2005, two or more computed tomography studies were obtained as part of routine postoperative surveillance in patients with Dacron grafts implanted to replace diseased aortic segments. Scans were digitized to evaluate the entire thoracic aorta. The median diameters of 547 grafts (18 to 34 mm) in the ascending (349) and descending (198) aorta were calculated from more than 2,000 postoperative computed tomography scans. In scans obtained 7 or fewer days after implantation, the median graft diameters increased from the manufacturer's measurement by 17% in the ascending aorta (n = 169; interquartile range, 11% to 21%; p < 0.0001) and 21% in the descending aorta (n = 63; interquartile range, 12% to 25%; p < 0.0001). From an initial scan within 30 days to at least one other within 18 months after implantation, ascending aorta grafts dilated further, at a median rate of 2.8% per year (n = 143; interquartile range, -2.2% to +6.9%; p = 0.0001). Descending grafts dilated less markedly: 1.1% per year (n = 80; interquartile range, -4.0% to +6.1%; p = 0.14). After 18 months, median graft expansion gradually diminished to less than 1% per year. Significant initial expansion and early growth of woven vascular Dacron grafts occurs; it is slightly different in the ascending and descending aorta. Graft expansion should be anticipated when selecting grafts for aortic valve-sparing procedures to prevent development of regurgitation, and, for endoluminal repair of thoracoabdominal aneurysms, to prevent development of type III endoleaks in the projected landing zone.

Strategy for Isolated Iliac Artery Aneurysms

We retrospectively reviewed 41 patients with isolated iliac artery aneurysms presenting over a 21-year period. The mean age was 72 years. Mean aneurysmal diameter was 6.0 cm (range, 3.2-13 cm). The aneurysms were located in the common iliac artery in 31 patients, internal iliac artery in 7, and both arteries in 3. Rupture occurred in 20 patients (49%). The frequency of rupture of isolated iliac artery aneurysms was significantly higher than that of abdominal aortic aneurysms (8%) during the same period. The 30-day mortality was 9.8%; death in all 4 patients was due to rupture of the aneurysm. The surgical procedure was aneurysmectomy and replacement with a bifurcated prosthetic graft in 24 patients (59%), closure of the common iliac artery with a femorofemoral crossover in 7, minilaparotomy in 3, thromboexclusion in 6, and endoluminal stent-graft repair in one. In contrast to abdominal aortic aneurysms, isolated iliac artery aneurysms can be treated by various methods other than replacement with a bifurcated prosthetic graft. When selecting a strategy for such aneurysms, it is important to choose an approach appropriate to the location and risk, because of the frequency of rupture.

PCA-induced respiratory depression simulating stroke following endoluminal repair of abdominal aortic aneurysm: a case report.

AimTo report a case of severe respiratory depression with PCA fentanyl use simulating stroke in a patient who underwent routine elective endoluminal graft repair for abdominal aortic aneurysm (AAA)Case presentationA 78-year-old obese lady underwent routine endoluminal graft repair for AAA that was progressively increasing in size. Following an uneventful operation postoperative analgesia was managed with a patient-controlled analgesia (PCA) device with fentanyl. On the morning following operation the patient was found to be unusually drowsy and unresponsive to stimuli. Her GCS level was 11 with plantars upgoing bilaterally. A provisional diagnosis of stroke was made. Urgent transfer to a high-dependency unit (HDU) was arranged and she was given ventilatory support with a BiPap device. CT was performed and found to be normal. Arterial blood gas (ABG) analysis showed respiratory acidosis with PaCO2 81 mmHg, PaO2 140 mmHg, pH 7.17 and base excess -2 mmol/l. A total dose of 600 mcg of fentanyl was self-administered in the 16 hours following emergence from general anaesthesia. Naloxone was given with good effect. There was an increase in the creatinine level from 90 μmol/L preoperatively to 167 μmol/L on the first postoperative day. The patient remained on BiPap for two days that resulted in marked improvement in gas exchange. Recovery was complete.