Clinical and Economic Benefits of Stent Grafts in Dysfunctional and Thrombosed Hemodialysis Access Graft Circuits in the REVISE Randomized Trial.

PURPOSE: To compare reinterventions and associated costs to maintain arteriovenous graft hemodialysis access circuits after rescue with percutaneous transluminal angioplasty (PTA), with or without concurrent Viabahn stent grafts, over 24 months. MATERIALS AND METHODS: This multicenter (n = 30 sites) study evaluated reintervention number, type, and cost in 269 patients randomized to undergo placement of stent grafts or PTA alone. Outcomes were 24-month average cumulative number of reinterventions, associated costs, and total costs for all patients and in 4 groups based on index treatment and clinical presentation (thrombosed or dysfunctional). RESULTS: Over 24 months, the patients in the stent graft arm had a 27% significant reduction in the average number of reinterventions within the circuit compared to the PTA arm (3.7 stent graft vs 5.1 PTA; P = .005) and similar total costs ($27,483 vs $28,664; P = .49). In thrombosed grafts, stent grafts significantly reduced the number of reinterventions (3.7 stent graft vs 6.2 PTA; P = .022) and had significantly lower total costs compared to the PTA arm ($30,329 vs $37,206; P = .027). In dysfunctional grafts, no statistical difference was observed in the number of reinterventions or total costs (3.7 stent graft vs 4.4 PTA; P = .12, and $25,421 stent graft and $22,610 PTA; P = .14). CONCLUSIONS: Over 24 months, the use of stent grafts significantly reduced the number of reinterventions for all patients, driven by patients presenting with thrombosed grafts. Compared to PTA, stent grafts reduced overall treatment costs for patients presenting with thrombosed grafts and had similar costs for stenotic grafts.

Real-Time Super Selective Venous Sampling in Remedial Parathyroid Surgery.

BACKGROUND: Remedial cervical exploration for persistent or recurrent primary hyperparathyroidism can be technically difficult, but is expedited by accurate preoperative localization. We investigated the use of real-time super selective venous sampling (sSVS) in the setting of negative noninvasive imaging modalities. STUDY DESIGN: We performed a retrospective analysis of a prospective database incorporating real-time sSVS in a tertiary academic medical center. Between September 2001 and April 2014, 3,643 patients were referred for surgical treatment of primary hyperparathyroidism. Of these, 31 represented remedial patients who had undergone one (n=28) or more (n=3) earlier cervical explorations and had noninformative, noninvasive preoperative localization studies. RESULTS: We extended the use of the rapid parathyroid hormone assay in the interventional radiology suite, generating near real-time data facilitating onsite venous localization by a dedicated interventional radiologist. The predictive value of real-time sSVS localization was investigated. Overall, sSVS correctly predicted the localization of the affected gland in 89% of cases. Of 31 patients who underwent sSVS, a significant rapid parathyroid hormone gradient was identified in 28 (90%), localizing specific venous drainage of a culprit gland. All patients underwent subsequent surgery and were biochemically cured, with the exception of one who had metastatic parathyroid carcinoma. Three patients with negative sSVS were also explored and cured. CONCLUSIONS: Preoperative parathyroid localization is of paramount importance in remedial cervical explorations. Real-time sSVS is a sensitive localization technique for patients with persistent or recurrent primary hyperparathyroidism, when traditional noninvasive imaging studies fail. These results validate the utility and benefit of real-time sSVS in guiding remedial parathyroid surgery.

Successful treatment of a proximal type I endoleak with HeliFX EndoAnchors.

We report the use of Aptus HeliFX EndoAnchors for endovascular treatment of a proximal type I endoleak after previous endovascular aneurysm repair (EVAR) of a ruptured abdominal aortic aneurysm. An 81-year-old man had been treated with EVAR after a ruptured 12 × 11 cm abdominal aortic aneurysm. Standard computed tomographic angiography follow-up demonstrated a proximal type I endoleak. Because of the highly angulated neck and close position of the endograft to the renal arteries, placement of a proximal extension cuff was prohibited; therefore, the endoleak was treated with an alternative approach using the Aptus HeliFX EndoAnchors. Nine EndoAnchors were successfully placed circumferentially on the proximal site of the endograft. This successfully treated the endoleak by excluding the aneurysm sac from the circulation. Computed tomographic angiography follow-up after 3 months showed no residual type I endoleak. This case shows that placement of EndoAnchors can serve as a viable treatment option for proximal type I endoleaks after failed EVAR.

Lower extremity limb salvage with cryoplasty: a single-center cohort study.

Endovascular techniques have been playing an increasing role in managing lower extremity chronic critical limb ischemia (CLI) in patients considered poor or non-candidates for surgical revascularization secondary to co-morbidities such as coronary artery disease, uncontrolled hypertension, diabetes mellitus or inadequate conduit. This study reviews our recent clinical experience in the treatment of peripheral artery disease solely using cryoplasty. A retrospective cohort study was performed. The cohort consisted of 88 patients who underwent lower extremity revascularization utilizing cryoplasty between December 2003 and August 2007. Indications for intervention included poor wound healing after forefoot amputation or persistent ulceration of the foot, disabling claudication and rest pain. Kaplan-Meier analysis was performed to assess salvage rates. One hundred twenty-six lesions were treated in 88 patients. Technical success rate was 97%. Limb salvage rates were 75 and 63% for patients with critical limbs ischemia after one and three years, respectively. A history of smoking was associated with a threefold increased risk of limb loss. In conclusion, endovascular management of lower extremity lesions with cryoplasty is an emerging and viable paradigm in the treatment of CLI in an attempt to preserve limbs and avoid major amputations.

The chimney procedure is an emergently available endovascular solution for visceral aortic aneurysm rupture.

A 79-year-old woman presented with a ruptured saccular thoracoabdominal aortic aneurysm involving the celiac and mesenteric artery. The patient was unfit for open surgical repair. A "chimney" procedure was performed, which involved placement of stents in the aortic side branches alongside the endograft. The patient underwent another chimney procedure 2 weeks later for a type I endoleak. Computed tomography angiography (CTA) at 1 and 6 months showed a good result with no endoleaks or graft migration. The chimney procedure provides an alternative for emergency patients unfit for open repair and has the advantage that stents can be used that are already available in most institutions.

Cryosurgery: A review.

Cryosurgery dates back to the 19th century, with the description of the benefits of local application of cooling for conditions such as pain control. Once commercial liquefied gases became available, more progress was made in the use of cryotherapy for localized lesions. As understanding of disease response to freezing increased, safer techniques for performing freezing procedures helped prepare its clinical application in different clinical situations, such as prostate disease and bronchial cancers. Cryosurgical techniques are less invasive and have lower morbidity compared with surgical resection. However, the use of cryosurgery has been limited by a lack of good understanding of the underlying mechanisms of tissue destruction. To apply cryosurgery clinically, and to extend its use, it is important to understand the mechanisms of freeze injury on cells, and to control the thermal parameters.

Rapid parathyroid hormone analysis during venous localization.

OBJECTIVE: To determine the usefulness of the rapid parathyroid hormone (PTH) assay during venous localization for primary hyperparathyroidism (1 degrees HPTH). SUMMARY BACKGROUND DATA: Remedial exploration for persistent 1 degrees HPTH poses a significant challenge when noninvasive preoperative localization studies are negative. Based on experience with the intraoperative rapid PTH assay, this technique was extrapolated to the interventional radiology suite and generated near real-time data for the interventional radiologist employing on-site hormone analysis, with a 12-minute turnaround time from blood sampling to assay result. METHODS: Between November 1997 and July 2002, 446 patients with 1 degrees HPTH were referred for treatment. Of these, 56 (12.5%) represented remedial patients who had each undergone one or more previous cervical explorations. Noninvasive imaging studies were positive for or suggestive of localized disease in 49/56 (87.5%) of these patients, who therefore proceeded directly to surgical exploration. Seven patients with persistent 1 degrees HPTH and negative noninvasive studies underwent selective venous sampling employing a rapid PTH assay in the interventional suite. RESULTS: Venous localization demonstrated an apparent PTH gradient in six of the seven patients. In three, a subtle gradient demonstrated in near real-time prompted additional sampling, which confirmed an unequivocal hormone gradient. In an additional case, the absence of a gradient on initial sampling prompted further sampling, which was positive. All of the patients were explored, and in five of the six patients with a positive PTH gradient, a parathyroid adenoma (mean weight 636 +/- 196 mg) was resected from a location predicted by venous localization. In the sixth patient with a positive gradient, parathyroid tissue was not identified; however, there was a significant fall in the intraoperative PTH values, and immediate postoperative and follow-up laboratory data at 1 month are indicative of a cure. In the one patient with negative localization, abnormal parathyroid tissue could not be located during surgical exploration. CONCLUSIONS: The rapid PTH assay is a major adjunct for obtaining informative venous localization in patients with persistent 1 degrees HPTH. This information is extremely helpful to the surgeon in this challenging group of patients and resulted in a 100% cure rate when a venous gradient was demonstrated. The authors now employ this technique routinely in remedial patients with negative noninvasive imaging studies.