Ralf Kolvenbach

Endovascular management of ascending aortic pathology

BACKGROUND Endovascular treatment of the ascending aorta is particularly challenging because of the anatomic features of this aortic segment. Only patients without connective tissue disorders, clinically relevant aortic regurgitation or stenosis, or concomitant coronary artery disease can be considered for an endovascular procedure. We report our results in a series of patients with aneurysms or intramural hematoma, penetrating ulcers, or floating thrombus who were scheduled for stent grafting. METHODS Only patients with ascending aortic pathology who were unfit for open surgery were treated with an endograft. When preoperative computed tomography imaging showed severe calcification of the aortic arch or thrombus lining, temporary clamping of the carotid arteries before wire and catheter introduction was performed. An extracorporeal bypass from the right groin to both carotid arteries with a roller pump was established and maintained during the procedure. The endograft was placed across the aortic valve into the left ventricle and deployed in a retrograde fashion. At the end of the procedure, ventriculography and, if necessary, coronary angiography was performed to rule out any damage to the left ventricle or the valve apparatus. RESULT Eleven patients were scheduled for stent graft exclusion of ascending aortic pathology. In five cases because of discrepancies in length measurements and sizing, the thoracic endograft was cut to length intraoperatively after partial deployment on the operating table and reloaded to avoid covering of the innominate artery. The mean length of the ascending aorta covered was longer in aneurysm patients than in those with dissection. An 81-year-old patient presented with a type Ia leak. The distal landing zone in one patient was enlarged by debranching. One patient died after wire perforation of the left ventricle, and one patient sustained a cerebral stroke. Combined morbidity and mortality was 18%, and the technical success rate was 91%. CONCLUSIONS Stent grafting of the ascending aorta is technically feasible but should be reserved for selected high-risk patients only, preferably in centers where vascular specialists cooperate closely with interventional cardiologists. Cardiac surgery with cardiopulmonary bypass is still the gold standard to treat ascending aortic aneurysms. Stent graft exclusion of more advanced and complex ascending aortic pathology should be performed only in centers with the necessary experience in transvalvular cardiac procedures.

Safety and feasibility of a novel transcervical access neuroprotection system for carotid artery stenting in the PROOF Study.

BACKGROUND Randomized controlled trials have shown that periprocedural rates of stroke and death are higher with carotid artery stenting (CAS) than with carotid endarterectomy (CEA) in the treatment of carotid artery stenosis. Diffusion-weighted magnetic resonance imaging (DW-MRI) has shown higher rates of clinically silent new ischemic brain lesions when CAS is performed as compared with CEA. The Silk Road Medical Embolic PROtectiOn System: First-In-Man (PROOF) Study is a single-arm first-in-man study using the MICHI Neuroprotection System (Silk Road Medical Inc, Sunnyvale, Calif), a novel transcervical access and cerebral embolic protection system. This system enables stent implantation under controlled blood flow reversal of the carotid artery, also known as Flow Altered Short Transcervical Carotid Artery Stenting (FAST-CAS). METHODS Between March 2009 and February 2010, a total of 44 subjects were enrolled into the study. The primary composite endpoint was major stroke, myocardial infarction, or death within 30 days. Forty-three patients (97.7%) completed the study through the 30-day endpoint. One patient was lost to follow-up. In a subgroup of consecutive subjects, DW-MRI examinations were performed preprocedure and within 24 to 48 hours after the stent implantation. Blinded independent neuroradiologists reviewed all DW-MRI studies and confirmed the absence or presence of new ischemic brain lesions. RESULTS All enrolled patients were successfully treated, and no major adverse events were seen through the follow-up period. Thirty-one subjects had DW-MRI examinations. Of these, five patients (16%) had evidence of new ischemic brain lesions but no clinical sequelae. Transient intolerance to reverse flow was reported in 9% of cases, but in all cases, a stent was successfully placed, and the intolerance was managed by minimizing the duration of reverse flow during the procedure. CONCLUSION In this first-in-man experience, FAST-CAS using the MICHI Neuroprotection System was shown to be a safe and feasible method for carotid revascularization. DW-MRI findings suggest controlled reverse flow provides cerebral embolic protection similar to that seen with CEA.

Total laparoscopic aortofemoral bypass as a routine procedure for the treatment of aortoiliac occlusive disease

The purpose of our study was to evaluate whether total laparoscopic aortofemoral bypass can be performed routinely in patients who require surgical intervention for aortoiliac occlusive disease. In a prospective study, 68 consecutive patients underwent total laparoscopic aortofemoral bypass between 2002 and 2004. Among these patients, there were 50 men and 18 women, with a mean age of 68.4 ± 9 years. The mean operating time was 199 minutes, with a mean aortic cross-clamp time of 85.8 minutes. There were five major complications (7.3%). The mean postoperative hospital stay was 6.3 days. Most of the younger patients could be discharged on the third or fourth postoperative day. Our results show that total laparoscopic aortic surgery can be offered as a routine procedure to the majority of patients with long-segment aortoiliac occlusive disease.

Video-assisted aortic surgery

BACKGROUND There are several laparoscopic techniques that can be used to perform a total or video-assisted aorto-femoral bypass grafting procedure. Major drawbacks of laparoscopic aortic surgery are the long operating times and the steep learning curve required for these procedures. Hand-assisted laparoscopy is a novel technique that allows surgeons to use their hands and laparoscopic instruments in the operative field while maintaining a pneumoperitoneum. STUDY DESIGN A prospective nonrandomized study was conducted in a community medical center. Any patient with aortoiliac occlusive disease or an abdominal aortic aneurysm who was determined to be suitable for a laparoscopic aorto-femoral bypass grafting procedure was included in the study. The main outcomes measured were: operating time, aortic cross-clamp time, incision size, complications, conversion rate to an open procedure, length of stay in the ICU, and postprocedural hospital stay. A concurrent control group of 20 patients was compared with the minimally invasive group. RESULTS Forty-one consecutive patients were scheduled for the laparoscopic operation. Conversion to an open procedure was necessary in three patients. There were two major complications, including the development of renal failure in one patient who died 28 days postoperatively. The mean postprocedural hospital stay was 4.5 +/- 2.5 days (range 2 to 15 days). The mean operating time was 163.1 +/- 38.7 minutes, including an aortic cross-clamp time of 38.3 +/- 9.7 minutes. Postoperative hospital stay and the time required in the ICU were significantly shorter after the laparoscopic procedure compared with a conventional bypass grafting procedure. CONCLUSIONS Hand-assisted laparoscopy is a minimally invasive technique with operating times and outcomes similar to those of conventional procedures. The possibilities of this technique in patients with aortoiliac disease should be evaluated in a prospective randomized study.

Anterograde recanalisation of the radial artery followed by transradial angioplasty

We report a patient with critical hand ischemia after transradial coronary angioplasty. The radial artery occlusion was confirmed by angiography. The report discusses the role of angioplasty for the treatment of symptomatic radial artery occlusion.

Total Laparoscopic Aortic Surgery Versus Minimal Access Techniques: Review Of More Than 600 Patients

In the following paper we describe our experience with a large number of patients in which either a laparoscopic assisted procedure or a total laparoscopic operation was performed. From 1996 until 2005 a total number of 638 aortic patients were operated on using a total laparoscopic or a laparoscopic assisted approach. A total laparoscopic operation was accomplished in 236 cases. A laparoscopic assisted aortic operation was performed in 402 patients. In aneurysm patients a tube graft was more frequently implanted. Thirty-day mortality was significantly higher in patients with a total laparoscopic abdominal aortic aneurysm repair (3.0%) compared to a laparoscopic assisted procedure (1.8%). There was no significant difference in mortality in patients with occlusive disease and a total laparoscopic aortofemoral bypass versus a laparoscopically assisted operation. The same tendency could be observed when analyzing the incidence of major perioperative complications. Again we found no significant difference in patients with occlusive disease yet more severe complications directly related to the operation in patients with a total laparoscopic aneurysm repair. There was a significantly increased complication rate in total laparoscopic aortoiliac repair with a bifurcated prosthesis compared to a tube graft repair: a tendency we could not observe in aneurysm patients with a laparoscopic assisted operation. Our data also show that there is a lot of room for technical improvements such as stapling devices or special grafts to reduce total operating times as well as the period of aortic crossclamping. The routine use of a minilaparotomy can hardly be a solution considering the technical drawbacks such as impaired vision and long term complications like ventral hernias. Compared to open surgery the midterm results of laparoscopic aortic procedures are promising. The time has come to prove that good results can be obtained in more than a few specialized centers.

A randomised comparison of transradial and transfemoral approach for carotid artery stenting: RADCAR (RADial access for CARotid artery stenting) study

AIMS Limited data exist on radial access in carotid artery stenting. This multicentre prospective randomised study was performed to compare the outcome and complication rates of transradial and transfemoral carotid artery stenting. METHODS AND RESULTS The clinical and angiographic data of 260 consecutive patients with high risk for carotid endarterectomy, treated between 2010 and 2012 by carotid stenting with cerebral protection, were evaluated. Patients were randomised to transradial (n=130) or transfemoral (n=130) groups and several parameters were evaluated. Primary combined endpoint: major adverse cardiac and cerebral events, rate of access-site complications. Secondary endpoints: angiographic outcome of the procedure, fluoroscopy time and X-ray dose, procedural time, crossover rate to another puncture site and hospitalisation in days. Procedural success was achieved in all 260 patients (100%), the crossover rate was 10% in the TR and 1.5% in the TF group (p<0.05). A major access-site complication was encountered in one patient (0.9%) in the TR group and in one patient (0.8%) in the TF group (p=ns). The incidence of major adverse cardiac and cerebral events was 0.9% in the TR and 0.8% in the TF group (p=ns). Procedure time (1,620 [1,230-2,100] vs. 1,500 [1,080-2,100] sec, p=ns) and fluoroscopy time (540 [411-735] vs. 501 [378-702] sec, p=ns) were not significantly different, but the radiation dose was significantly higher in the TR group (195 [129-274] vs. 148 [102-237] Gy*cm2, p<0.05) by per-protocol analysis. Hospitalisation days were significantly lower in the TR group (1.17±0.40 vs. 1.25±0.45, p<0.05). By intention-to-treat analysis there was a significantly higher radiation dose in the TR group (195 [130-288] vs. 150 [104-241], p<0.05), but no difference in major events (0.9 vs. 0.8, p=ns) and length of hospitalisation in days (1.4±2.6 vs. 1.25±0.45, p=ns). CONCLUSIONS The transradial approach for carotid artery stenting is safe and efficacious; however, the crossover rate is higher with transradial access. There are no differences in the total procedure duration and fluoroscopy time between the two approaches but the radiation dose is significantly higher in the radial group, and the hospitalisation is shorter with the use of transradial access by per-protocol analysis. By evaluating the patient data according to intention-to-treat analysis we found no difference in major adverse events and hospitalisation. In both groups, vascular complications rarely occurred.

Experience with the sandwich technique in endovascular thoracoabdominal aortic aneurysm repair

BACKGROUND The sandwich technique is an endovascular off-the-shelf solution for patients with thoracoabdominal aortic aneurysms (TAAAs). In a sandwich configuration, the chimney stent runs in the middle of a space created by two or three aortic endografts. METHODS All patients with TAAAs who were treated with the sandwich technique were included in the study. Self-expanding Viabahn grafts (W. L. Gore and Associates Inc, Flagstaff, Ariz) were used as parallel grafts in the renal arteries and visceral vessels. Caudad-facing chimney grafts were used for the visceral arteries and cephalad-facing periscope grafts for the renal arteries. RESULTS During the study period, 32 patients with TAAAs were treated with sandwich grafts. Indication for the procedure in 43% was an acute onset of symptoms, including two patients with a rupture and a retroperitoneal hematoma. Three patients required an additional debranching procedure. A total of 104 chimney grafts were implanted. Two patients died postoperatively because of the operation. Major adverse events were recorded in five patients, including one patient with persistent paraplegia and two with permanent renal failure requiring dialysis. The incidence of chimney graft occlusion was higher in patients with three or four parallel grafts than in those with two chimney grafts only. Patients with chronic dissections had a 12-times higher incidence of chimney graft occlusion than aneurysm patients. The number of patients with type I or III endoleaks was higher in the group with three or four parallel grafts. CONCLUSIONS The sandwich technique is an off-the-shelf endovascular alternative to treat patients with TAAAs in an emergent setting. The combination of chimney grafts with a periscope configuration enables a rapid endovascular aneurysm exclusion with acceptable midterm results.

Intraoperative Adjunctive Stem Cell Treatment in Patients with Critical Limb Ischemia Using a Novel Point-of-Care Device

INTRODUCTION In a prospective trial we tested whether adjunctive intraoperative stem cell treatment in patients with critical limb ischemia (CLI) can be performed safely in combination with bypass surgery and/or interventional treatment. The end point of our study was the safety and integrity of a novel point-of-care system used in patients with CLI. METHODS We included only patients with CLI and tissue loss according to Rutherford categories 4-6. The Harvest Bone Marrow Aspirate Concentrate System consists of an automated, microprocessor-controlled dedicated centrifuge with decanting capability and the accessory BMAC Pack for processing a patients bone marrow aspirate (BMA). The centrifuge is portable and enables BMA to be rapidly processed in the operating room to provide an autologous concentrate of nucleated cells for immediate injection. The surgeon aspirated 120 ml BMA from the iliac crest. RESULTS Eight consecutive patients were treated according to the study protocol. The mean follow-up period was 9.2 months (range 2-18). Stem cells were always injected during the final revascularization attempt. One minor amputation and two major amputations were required. In five of eight patients there was a discrete increase in the ankle-brachial index post-stem cell treatment. The dose of stem cells after centrifugation was 17.2 (range 13.8-54.2)x10E6 CD34-positive cells and 7.8 (range 1.8-35.9)x10E6 CD133-positive cells. The injected dose of VEGFR-2-coexpressing stem cells was 0.5-5.7x10E4. CONCLUSION We were able to show that the buffy coat preparation using a point-of-care system is a simple and fast method to enrich stem cells from BMAs. This automated system gives high recovery rates and good reproducibility.

Redone endoscopic perforator surgery : feasibility and failure analysis

PURPOSE In many hospitals and medical practices, subfascial endoscopic perforator surgery (SEPS) has become the treatment of choice in patients with incompetent perforator veins and active venous ulcers. A substantial number of surgeons consider SEPS to be an operation that can be performed only once because extensive scarring and narrowing of the subfascial space make a second endoscopic operation impossible. It is the purpose of this report to prove the feasibility, efficacy, and safety of a second SEPS procedure. METHODS Within a period of 30 months, 105 primary SEPS procedures were performed in patients with healed or still active ulcers. In addition to these cases, within a period of 30 months, a consecutive number of 19 patients were examined and scheduled for a second SEPS procedure. All patients were in class 5 with healed ulcers or in class 6 with still active ulcers. The CEAP classification of the American Venous Forum was used to evaluate the results and to calculate the clinical, disability, and outcome scores. The redone operation was performed by using CO(2) insufflation, a dual-port technique, and subfascial balloon dissection. RESULTS In two patients conversion to a conventional procedure was necessary. There were no major complications, but there was a 21% incidence of minor problems, such as hematoma or cellulitis. The mean total clinical score improved after surgery from 7.91 to 3.23 (P <.01), the disability score changed from 1.10 to 0.57 after surgery (P <.02), and the clinical outcome score was 1. 47 after surgery (P <.001). Cumulative ulcer healing could be achieved in 85.8% of class 6 patients. Failure analysis revealed that an incomplete subfascial dissection had been performed during the first endoscopic operation. A septum intermusculare medialis or an intact deep posterior fascia with incompetent Cockett II perforators were major factors contributing to the initial treatment failures. In addition to incompetent perforators, postthrombotic deep venous reflux was seen in eight (42.1%) patients, and four (21%) patients had a combination of secondary reflux and obstruction. CONCLUSION Subfascial endoscopic procedures can be redone safely. In addition to exploring the superficial posterior compartment, the deep posterior compartment must be opened to prevent recurrent symptoms in patients with incompetent perforator veins.