Changing pattern of surgical revascularization for critical limb ischemia over 12 years: endovascular vs. open bypass surgery.

OBJECTIVE: This study is a review and evaluation of our 12-year experience of revascularization for critical limb ischemia (CLI) with angioplasty/stenting and bypass surgery to identify specific trends of procedure volume and outcomes in this particular group. METHODS: Endovascular and open bypass procedures done for CLI by a single surgeon between 1993 and 2004 were evaluated retrospectively. Thrombolysis and thrombectomy procedures done as the only revascularization procedure were excluded from analysis. The data were divided into three groups by time periods: the first period, 1993 to 1996; the second period, 1997 to 2000; and the third period, 2001 to 2004. Outcomes were defined according to the reporting standards of the Society for Vascular Surgery/International Society for Cardiovascular Surgery. The study included 416 procedures done in 237 limbs in 192 patients. The mean follow-up was 23 months (range, 1 to 122 months). RESULTS: Primary revascularization procedures for CLI were angioplasty in 153 limbs (65%) and bypass surgery in 84 (35%). Subsequent procedures were angioplasty in 102 limbs (57%) and open surgery (bypass and/or patch angioplasty) in 77 limbs (43%). The rates for technical and clinical success and complications in the entire group were 99%, 95%, and 4%, respectively. One patient died perioperatively (0.5%). Among the three periods, TransAtlantic Inter-Society Consensus lesion types were significantly more severe in patients in the first period (P < .05). Additionally, the complication rate was significantly higher and the mean hospital stay was significantly longer in the first period compared with the second and third periods (P < .05). Furthermore, between the first and third periods, the number of endovascular revascularization procedures done as primary and secondary procedures significantly increased from 15 to 84 (+460%) and from 13 to 57 (+340%), whereas the number of open surgical procedures done as primary and secondary procedures decreased from 39 to 20 (-49%) and from 35 to 18 (-49%), respectively (P < .0001). The assisted primary patency rates in the third period were significantly higher than those in the first and second periods (P = .012); otherwise, the long-term outcomes among the three periods were not statistically different. Multivariate analysis revealed that, while controlling for other factors, the third period showed improvement in the primary patency (P = .032) and assisted primary patency (P = .051), and the bypass group showed improvement in the primary patency (P = .008). CONCLUSIONS: In our experience, open surgical procedures for the treatment of CLI have been largely replaced by angioplasty procedures without compromising outcomes. Angioplasty is a feasible, safe, and effective procedure and can be the procedure of choice for the primary and secondary treatment of CLI. Open surgical procedures can be reserved for lesions technically unsuitable for endovascular procedures and patients who do not demonstrate clinical improvement after angioplasty.

Thoracic outlet syndrome: pattern of clinical success after operative decompression.

OBJECTIVE: To evaluate the pattern of clinical results in patients with neurogenic thoracic outlet syndrome (N-TOS) after operative decompression and longitudinal follow-up. METHODS: From May 1994 to December 2002, 254 operative sides in 185 patients with N-TOS were treated by the same operative protocol: (1) transaxillary first rib resection and the lower part of scalenectomy for the primary procedure with or without (2) the subsequent upper part of scalenectomy with supraclavicular approach for patients with persistent or recurrent symptoms. This retrospective cohort study included 38 men and 147 women with an age range of 19 to 80 years (mean, 40 years). Evaluated were primary success, defined as uninterrupted success with no procedure performed, and secondary success, defined as success maintained by the secondary operation after the primary failure. Success was defined as > or =50% symptomatic improvement judged by the patient using a 10-point scale, returning to preoperational work status, or both. RESULTS: Follow-up was 2 to 76 months (mean, 25 months). Eighty sides underwent a secondary operation for the primary clinical failure. No technical failures and no deaths occurred < o =30 days after the operations. The complication rate was 4% (13/334) and consisted of 7 pneumothoraxes, 3 subclavian vein injuries, 1 nerve injury, 1 internal mammary artery injury, and 1 suture granuloma. Of 254 operative sides, the primary and secondary success was 46% (118/254) and 64% (163/254). Most the primary failures (90%, 122/136) and the secondary failures (66%, 23/35) occurred < or =18 months after the respective operation. CONCLUSIONS: The long-term results of operations for TOS in this study were much worse than those initially achieved, and most of the primary and secondary failures occurred < or =12 months of the respective operations. A minimum of 18-month follow-up on patients and standardized definition of the outcomes are necessary to determine the true effectiveness and outcome of operative treatment of N-TOS.

Laparoscopic aortic reinforcement and endovascular graft placement in swine: a new external wrap.

OBJECTIVE: To evaluate the feasibility, safety, and histological response of laparoscopic external aortic wrap implantation in conjunction with an endovascular stent/stent-graft placement in the infrarenal aorta in a porcine model. METHODS: Seven swine underwent laparoscopic retroperitoneal placement of a custom-made Dacron fabric wrap placed around the infrarenal aorta to create a landing zone for an endovascularly placed aortic stent/stent-graft. RESULTS: Technical success was achieved in all animals without any major complications. Follow-up ranged from 1 to 4 weeks. At necropsy, the external wraps were well incorporated into the adventitia, and the stents/stent-grafts were well incorporated into the intima. Small patches of medial necrosis of the aortic wall were observed in one animal in the stent model and in two animals in the stent-graft model. There was no transmural necrosis observed. CONCLUSIONS This adjunct technique, an external wrap around the infrarenal aorta combined with endovascular grafting, is feasible and deserves further studies into how it may be used to facilitate endovascular repair of aortic aneurysms. CLINICAL RELEVANCE: We hypothesize that our new device could provide capability of altering the proximal neck morphology of abdominal aortic aneurysm and reinforcement to the aortic wall. This, in turn, could improve eligibility for endovascular aneurysm repair and prevent or treat type I endoleak and graft migration. Future investigations will involve evaluation of the long-term effect of the external aortic wrap on the integrity of the aortic wall in an animal model and testing the clinical usefulness of this new technique.

Negative-pressure pulmonary edema complicated by acute respiratory distress syndrome in an orangutan (Pongo pygmaeus abelii).

A 22-yr-old, 86-kg, morbidly obese female orangutan (Pongo pygmaeus abelii) was immobilized and transported to the Denver Zoological Gardens hospital for a routine physical examination. Immediately after arriving at the hospital, cyanosis and apparent inadequate ventilatory efforts were noted. Clinically significant hypoxia occurred despite attempts to ventilate the orangutan through face mask, and attempts to place an endotracheal tube began. A large volume of pink-tinged frothy fluid flowed from the trachea when the laryngoscope was inserted into the oropharynx. Severe pulmonary edema due to negative-pressure pulmonary edema, precipitating life-threatening hypoxia was suspected. The orangutan was maintained on a mechanical ventilator using the neuromuscular blocking agent cisatracurium besylate and sedation with periodic doses of isoflurane and midazolam for 48 hr. Positive end-expiratory pressure was used while the orangutan was ventilated mechanically to improve respiratory function. The edema and hypoxia improved, but respiratory arrest ensued 30 min after extubation, when the orangutan was removed from mechanical ventilation. Necropsy and histopathology demonstrated that serious lung injury had led to acute respiratory distress syndrome.