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Brad L Johnson

Publications and source records attributed to Brad L Johnson.

At least 19 recordsLinked to original sources
PubMed2007

Plaque excision with the Silverhawk catheter: early results in patients with claudication or critical limb ischemia.

OBJECTIVE: This study was conducted to detail the early experience after infrainguinal atherectomy using the Silverhawk plaque excision catheter for the treatment of symptomatic peripheral vascular disease. METHODS: A prospective database was established in August 2004 in which data for operations, outcomes, and follow-up were recorded for patients undergoing percutaneous plaque excision for peripheral arterial occlusive disease. Society for Vascular Surgery (SVS) ischemia scores and femoropopliteal TransAtlantic Inter-Society Consensus (TASC) criteria were assigned. A follow-up protocol included duplex ultrasound surveillance at 1, 3, and 6 months and then yearly thereafter. Standard statistical analyses were performed. RESULTS: During a 17-month period, 66 limbs of 60 patients (37 men [61.7%]) underwent 70 plaque excisions (four repeat procedures). Indications included tissue loss based on SVS ischemia at grades 5 and 6 (25/70), rest pain at grade 4 (22/70), and claudication at grades 2 to 3 (23/70). The mean lesion length was 8.8 +/- 0.7 cm. The technical success rate was 87.1% (61/70). Adjunctive treatment was required in 17 procedures (24.3%), consisting of 14 balloon angioplasties and three stents. Femoropopliteal TASC criteria included 5 TASC A lesions, 14 TASC B lesions, 32 TASC C lesions, and 19 TASC D lesions. Although 17 plaque excisions included a tibial vessel, no patient underwent isolated tibial atherectomy. The mean increase in ankle-brachial index was 0.27 +/- 0.04 and in toe pressure, 20.3 +/- 6.9 mm Hg. Mean duplex ultrasound follow-up was 5.2 months (range, 1 to 17 months). One-year primary, primary assisted, and secondary patency was 61.7%, 64.1%, and 76.4%, respectively. Restenosis or occlusion developed in 12 patients (16.7%) and was detected at a mean of 2.8 +/- 0.7 months. Restenosis or occlusion was significantly more common (P < .05) in patients with TASC C and D lesions compared with patients with TASC A and B lesions. Six (8.3%) of 12 patients underwent reintervention on the basis of duplex ultrasound surveillance results. Four (33.3%) of 12 patients experienced reocclusion during the same hospitalization, and amputation and open revascularization were required in two patients each. CONCLUSIONS: Percutaneous plaque excision is a viable treatment option for lower extremity revascularization. Outcomes are related to ischemia and lesion severity. Patency and limb salvage rates are equivalent to other endovascular modalities.

Catheterization, Peripheral↗
PubMed2006

Use of antibiotic-loaded polymethylmethacrylate beads for the treatment of extracavitary prosthetic vascular graft infections.

PURPOSE: This study was conducted to assess the efficacy of antibiotic-loaded polymethylmethacrylate (PMMA) beads in the management of lower extremity extracavitary prosthetic arterial graft infection. METHODS: This was a retrospective review of 34 patients treated for vascular surgical site (VSS) infections involving 36 prosthetic lower extremity arterial bypasses using antibiotic-loaded PMMA beads and culture-specific parenteral antibiotics for 4 to 6 weeks. Sites of graft infection were explored, debrided, and cultured. As determined from the results of Gram's stains of VSS purulence, PMMA powder was polymerized with an antibiotic (vancomycin, daptomycin, or tobramycin/gentamicin, or a combination), molded into a chain of beads, and implanted adjacent to the infected graft after debridement and pulsed-spray antibacterial lavage. All wounds were closed primarily with planned exploration to verify sterilization before a graft preservation or in situ replacement procedure. Treatment outcomes, including wound sterilization, were analyzed based on tissue culture isolates, procedures for persistent infection, and freedom from graft infection. RESULTS: Cultures isolated 42 pathogens, (32 gram-positive, 9 gram-negative, 1 Candida albicans) with methicillin-resistant Staphylococcus aureus (MRSA) cultured from 16 (44%) of 36 surgical site infections. As determined from the initial operative Gram's stain or a prior culture result, vancomycin PMMA beads were implanted in 29 of 36 VSS infections at the first procedure; daptomycin (n = 4) or tobramycin (n = 3) beads were implanted in the rest. Repeat VSS exploration and culture results led to an average of 2.5 antibiotic bead replacements before definitive treatment. A sterile (no growth on tissue culture) VSS was achieved in 87% of cases before a graft preservation (n = 16) or in-situ replacement of an infected graft (n = 20) procedure. No patient deaths occurred. Early and late limb salvage was 100%. Infection recurred in 4 (11%) VSSs during a mean 23-month follow-up period, one within 3 months owing to unrecognized bowel injury associated with in situ replacement of an aortofemoral graft limb. CONCLUSION: Antibiotic-loaded PMMA beads may be a useful adjunct in the contemporary surgical management of VSS infection involving a prosthetic graft. Wound sterilization was achieved in most VSSs before graft preservation or an in-situ replacement procedure, including infections caused by MRSA, a pathogen isolated in half of the extracavitary prosthetic graft infections. This preliminary trial shows the potential benefit of this new technique, but further study is required to prove efficacy.

Aged↗
PubMed2006

Duplex ultrasound criteria for femorofemoral bypass revision.

PURPOSE: This study was conducted to evaluate the impact of duplex ultrasound surveillance on the patency of femorofemoral bypasses performed for symptomatic peripheral arterial occlusive disease (PAOD). METHODS: A retrospective review was conducted of 108 patients (78 men, 30 women) with a mean age of 62 +/- 10 years who underwent femorofemoral prosthetic (n = 100) or vein (n = 8) bypass grafting for symptomatic PAOD (claudication, 38%; rest pain, 41%; tissue loss, 11%; infection, 10%) during a 10-year period. Prior or concomitant inflow iliac artery stenting was performed in 26 patients (24%), and a redo femorofemoral bypass was performed in 19 patients (18%). Duplex ultrasound surveillance of the reconstruction was performed at 6-month intervals to assess patency, graft (midgraft peak systolic flow velocity) hemodynamics, and identify inflow or outflow stenotic lesions. Repair was recommended for a stenosis with a peak systolic velocity (PSV) >300 cm/s and a PSV ratio >3.5. Life-table analysis was used to estimate primary, assisted-primary, and secondary graft patency. RESULTS: During a mean 40-month follow-up (range, 2 to 120 months), 31 bypasses (29%) were revised: 19 duplex-detected stenosis involving the inflow iliac artery (n = 15) or anastomotic stenosis (n = 4), or both, 11 for graft thrombosis, and 1 for graft infection. Abnormal inflow iliac (PSV >300 cm/s) hemodynamics or a mid-graft PSV <60 cm/s was measured in eight of 11 grafts before thrombosis. Mean time to revision was 30 +/- 17 months. The primary graft patency at 1, 3, and 5 years was 86%, 78%, and 62%, respectively. Correction of duplex-detected stenosis resulted in assisted-primary patency of 95% at 1 year and 88% at 3 and 5 years (P < .0001, log-rank). Secondary graft patency was 98% at 1 year and 93% at 3 and 5 years. CONCLUSIONS: Vascular laboratory surveillance after femorofemoral bypass that included duplex ultrasound imaging of the inflow iliac artery and graft accurately identified failing grafts. A duplex-detected identified stenosis with a PSV >300 cm/s correlated with failure, and repair of identified lesions was associated with excellent 5-year patency.

Aged↗
PubMed2006

Increasing endovascular intervention for claudication: impact on vascular surgery resident training.

PURPOSE: To audit the caseloads of vascular surgery residents in the management of disabling claudication and assess the influence of endovascular procedures on overall operative experience. METHODS: A retrospective review was conducted of vascular surgery resident experience in the open and endovascular management of lower limb claudication during two 3-year periods (January 2000 to December 2002 and January 2003 to December 2005). The time periods differed with regard to number of surgical faculty with advanced endovascular skills (3 in the first period and 4 in the second) and the availability of portable operating room angiography equipment. RESULTS: During the 6-year period, the operative logs of vascular surgery residents indicated participation in 283 procedures [170 (60%) open surgical interventions, including 146 suprainguinal procedures] performed for claudication. The number of procedures increased by 62% (p<0.05) from the first period (n=108) to the second (n=175). Endovascular intervention to treat aortoiliac occlusive disease increased 4-fold (14 versus 56 interventions, p=0.01) compared to a decrease in open (bypass grafting, endarterectomy) surgical repair (45 to 31 procedures, p=0.22). The greatest change in resident experience was in endovascular intervention of infrainguinal occlusive disease: the case volume increased from 4 to 39 procedures (p=0.07) during the 2 time intervals. By contrast, the number of open surgical bypass procedures was similar (45 versus 49) in each 3-year period. CONCLUSION: An audit of resident experience demonstrated intervention for claudication has increased during the past 6 years. The increased operative experience reflects more endovascular treatment (atherectomy, angioplasty, stent-graft placement) of femoropopliteal and aortoiliac occlusive disease, but no decrease in open surgical operative experience for claudication. This increase in endovascular intervention may be related to a decrease in the threshold for intervention.

Databases, Factual↗
PubMed2006

Risk factors for recurrent hemorrhage after successful mesenteric arterial embolization.

The objective of this study was to describe the risk factors and to determine the outcomes after recurrent gastrointestinal hemorrhage after successful mesenteric arterial embolization A retrospective analysis was undertaken of a single-center experience with mesenteric arterial embolization performed for gastrointestinal hemorrhage over a 5-year period. Statistical analyses including Student's t test and Fisher's exact test were used to compare results. For the years 2001 through 2005, 36 patients (10 women; average age, 60.8 years) underwent 37 technically successful mesenteric embolizations for acute gastrointestinal hemorrhage. Two (5.4%) cases required surgical intervention for cessation of hemorrhage, and six (16.2%) patients died during their hospitalization after technically successful embolization. Nine (24.3%) patients experienced in-hospital rehemorrhage, and of these, five (55.6%) died. Risk factors for rehemorrhage included intra-abdominal malignancy (P < 0.05), transfusion requirement greater than 10 units before angiography (P < 0.05), and the source of hemorrhage other than solitary gastroduodenal artery hemorrhage (P < 0.05). The failure of initial embolization was associated with an increased incidence of death (55.6% vs 5.0%; P < 0.05) and operative intervention to cease hemorrhage (P < 0.05). The failure of technically successful mesenteric embolization is not uncommon and is associated with identifiable risk factors. Risk factor awareness should assist in patient selection for and timing of mesenteric embolization.

Adult↗
PubMed2005

Critical analysis of outcome determinants affecting repair of intact aneurysms involving the visceral aorta.

Visceral (mesenteric and/or renal) ischemia/reperfusion phenomena likely contribute to the greater operative risk associated with pararenal and lower thoracoabdominal aortic aneurysm (TAA) repair. To differentiate the relative adverse effects of aortic clamp level, visceral ischemic duration, and various pre- and perioperative factors shared with infrarenal aneurysm patients, a comparative analysis of early and late outcomes after open repair of intact infrarenal and visceral aortic aneurysms was undertaken. A retrospective review of our university experience from 1993-1999/2002 revealed 549 patients (mean age 70 +/- 8 years, 11% female) undergoing open repair of intact, degenerative aneurysms of the infrarenal (n = 391, 71%), juxtarenal (n = 78, 14%), suprarenal (n = 35, 7%), and type IV (n = 40, 7%) and type III (n = 5, 1%) TAA segments. All pararenal aneurysms required suprarenal (SR) or supravisceral (SV, above celiac or superior mesenteric artery) clamp placement. Concomitant renal reconstruction was done in 30% of visceral aortic and 3% of open infrarenal aneurysm repairs. Thirty-day adverse outcomes [death, renal failure (creatinine 2 x baseline or new dialysis), visceral (bowel, hepatic, renal, spinal cord, multiple organ dysfunction), and nonvisceral (cardiac, pulmonary, procedural) complications] were analyzed relative to patient and operative factors using univariate comparisons and multivariate stepwise logistic regression. Perioperative mortality rates varied significantly between aneurysm locations (infrarenal 2.1%, juxtarenal 2.6%, suprarenal 11.4%, TAA 13.3%; p < 0.01) and for clamp locations (infrarenal 2.1%, SR 3.0%, SV 10.8 %; p < 0.01) but were not different between juxtarenal (1.8% vs. 4.4 %) and SR (9.1% vs. 12.5%) aneurysms requiring SR or SV clamping, respectively. Visceral ischemic time (VIT) during SR or SV clamping, and not clamp location, was the only independent predictor of operative mortality [odds ratio (OR) = 10.8, 95% confidence interval (CI) 4-29]. Sensitivity analyses revealed VIT > 32 min to be the strongest predictor of early death. Visceral complication or renal failure affected 34% and 23% of visceral aortic (5% dialysis) and 7% and 5% (1% dialysis) of infrarenal repairs, respectively. VIT > 32 min, SV clamp placement, diabetes, and inflammatory aneurysm repair were each predictive of visceral complications and/or renal failure. Five-year survival rate was similar after visceral aortic (70%) and infrarenal (75%) repairs but negatively impacted only in patients with prior infrarenal abdominal aortic aneurysm repair and recurrent aneurysms (OR = 2.8, 95% CI 1.2-6.9). The high incidence of early adverse outcomes following repair of pararenal and lower thoracoabdominal aneurysms is primarily associated with excessive periods of renal and/or gut ischemia during visceral aortic clamp placement. However, nearly equivalent early and late survival was seen for visceral aortic and infrarenal repairs when VIT < 32 min was achieved.

Aged↗
PubMed2005

Midfoot amputations expand limb salvage rates for diabetic foot infections.

The persistent high incidence of limb loss resulting from advanced forefoot tissue loss and infection in diabetic patients prompted an evaluation of transmetatarsal (TMA) and transtarsal/midfoot amputations in achieving foot salvage at our tertiary vascular practice. Over the last 8 years, 74 diabetic patients required 77 TMAs for tissue loss and/or infection. Twelve (16%) of the patients had a contralateral below-knee amputation (BKA) and 26% (n = 20) had dialysis-dependent renal failure. Thirty-five (45%) limbs had concomitant revascularization (bypass grafting or percutaneous transluminal angioplasty), 32 (42%) had arterial occlusive disease by noninvasive testing and/or arteriography but were not or could not be revascularized, and seven (13%) had normal hemodynamics. Patient factors, arterial testing, operative complications, operative mortality (<60 days), wound healing (at 90 days), limb salvage, functional status, and survival were evaluated during a mean follow-up of 20 months (range 3-48). Operative mortality was 5% (n = 4) after TMA and/or midfoot amputation. Although 32 TMAs initially healed (44%), six BKAs were required 5-38 months later. Of the 41 nonhealing TMAs (56%), progressive infection/tissue loss necessitated major amputation of nine limbs. Chopart (n = 22) or Lisfranc (n = 10) midfoot amputations were done in the remaining 32 nonhealing TMAs. Despite additional wound revisions in 14 patients (44%), major amputation was needed in six limbs. However, functional ambulation was achieved in 23 of 25 (92%) limbs with healed midfoot amputations, and foot salvage was possible in 61% (25/41) of nonhealing TMAs. Overall limb salvage for TMA/midfoot procedures was estimated from Kaplain-Meier life tables to be 73%, 68%, and 62% at 1, 3, and 5 years, respectively, with only 50% of dialysis patients avoiding major amputation. Ankle pressure >100 mm Hg and a biphasic pedal waveform had a positive predictive value (PPV) of 79%, and toe pressure >50 mm Hg had a PPV of 91% for determining healing of TMA/midfoot amputations. One- and 3-year survival rates were only 72% and 69% for the entire cohort from life table estimates. Aggressive attempts at foot salvage are justified in diabetic patients with advanced forefoot tissue loss/infection after assuring adequate arterial perfusion. Transtarsal amputations salvaged over half of nonhealing TMAs with excellent functional results.

Aged↗
PubMed2005

The value of duplex surveillance after open and endovascular popliteal aneurysm repair.

OBJECTIVE: The objective of this study was to determine the clinical value of vascular laboratory surveillance after open or endovascular repair of popliteal aneurysm by analysis of the frequency and nature of secondary interventions performed. METHODS: Over an 8-year period, 55 popliteal artery aneurysms were repaired in 46 men (mean age, 72 years) by aneurysm ligation and bypass grafting (vein, 37; prosthetic, 7), endoaneurysmorrhaphy and interposition grafting (prosthetic, 3; vein, 1), or endograft exclusion (n = 7). Indications for intervention included aneurysm thrombosis with critical limb ischemia (n = 8), symptomatic (n = 10) or asymptomatic (n = 37), >1.75 cm popliteal aneurysm with mural thrombus. Catheter-directed thrombolysis was used in three limbs to restore aneurysm and tibial artery patency before open repair. Duplex ultrasound surveillance was performed after repair to identify residual and acquired lesions. Life-table analysis was used to estimate repair site intervention-free (primary) and assisted-primary patency. RESULTS: During a mean 20-month follow-up interval, 20 secondary procedures were performed in 18 (31%) limbs to repair duplex-detected graft stenosis (n = 10), repair site thrombosis (n = 5), vein graft aneurysm (n = 3), graft entrapment (n = 1), or type 1 endoleak (n = 1). Primary patency was 76% and 68% at 1 and 3 years, and was uninfluenced by tibial artery runoff status or type of bypass conduit. Open (n = 12) or endovascular (n = 8) secondary procedures were performed on 15 (12 vein, 3 prosthetic) bypass grafts, 2 endografts, and 1 interposition graft. Mean time to repair graft stenosis (11 months) was shorter than to repair of vein graft aneurysm (37 months). Assisted-primary patency was 93% and 88% at 1 and 3 years; redo bypass grafting was required and successful in five limbs. Limb salvage was 100%. CONCLUSIONS: One third of popliteal artery aneurysms repaired by open or endovascular procedures required a secondary intervention within 2 years of repair. Repair-site surveillance using duplex ultrasound was able to identify lesions that threaten patency, which resulted in excellent assisted patency and limb preservation rates when corrected.

Adult↗
PubMed2005

Improved outcomes in the recent management of secondary aortoenteric fistula.

OBJECTIVE: We reviewed the presentation, management, and late events in a recent experience with aortic graft-enteric communications (secondary aortoenteric fistula) to identify variables associated with poor outcomes. METHODS: Since 1991, 29 patients (19 men, 10 women; mean age, 70) presented with a secondary aortoenteric fistula. The duration from aortic graft implantation to aortoenteric fistula development ranged from 8 months to 180 months (mean, 47 months). Presenting symptoms included gastrointestinal bleeding (n = 25), sepsis and retroperitoneal abscess (n = 3), and ruptured para-anastomotic aneurysm (n = 1). One third (10/29) of patients were hypotensive at presentation. Repair was accomplished by graft excision with axillobifemoral bypass (17 simultaneous, 8 staged), graft excision with in situ deep vein replacement (n = 2), or graft excision with rifampin-treated prosthetic replacement (n = 2). Mean follow-up was 51 months, and the incidence of late events was reported by life table methods. RESULTS: The operative (< or = 30-day) mortality rate was 21%, with shock at presentation (P < .01), the need for preoperative transfusion (P < .01), and use of suprarenal aortic clamping during aortoenteric fistula repair (P = .03) associated with lethal outcome. Cumulative mortality related to aortoenteric fistula management was only 24% within an overall 5-year survival rate of 61%. Freedom from recurrent infection or amputation was 86% and 88% at 5 years, respectively, and assisted graft patency was 79%. Presence of staphylococcal species in 22% of patients and occasional operative findings of adjacent perigraft "biofilm" suggests that underlying indolent graft infection may contribute to the development of aortoenteric fistula in some cases. CONCLUSION: Outcomes associated with aortoenteric fistula repair were surprisingly favorable in the absence of preoperative hemodynamic instability.

Aged↗
PubMed2004

Optimizing infrainguinal arm vein bypass patency with duplex ultrasound surveillance and endovascular therapy.

OBJECTIVE: Infrainguinal bypass grafting with arm vein is associated with lower patency rates compared with saphenous vein conduits. In this study the effect of a duplex ultrasound surveillance program to enable identification and treat graft lesions with open or endovascular repair on patency was analyzed. METHODS: Over 9 years 89 infrainguinal arm vein (26% spliced vein) bypasses were performed to treat critical lower limb ischemia in 89 patients without adequate saphenous vein conduits. Seventy-six (85%) of the bypasses were repeat procedures. Grafts were assessed at operation with duplex ultrasound scanning, then enrolled in a surveillance program. Graft stenoses with peak systolic velocity greater than 300 cm/s and velocity ratio greater than 3.5, detected at duplex ultrasound scanning, were repaired with percutaneous transluminal balloon angioplasty (PTA) if specific criteria were met, including greater than 3 months since primary procedure, lesion length less than 2 cm, and graft diameter greater than 3.5 mm, or with open surgical repair for early appearing or extensive graft lesions. RESULTS: During a mean 26-month follow-up, duplex surveillance resulted in a 48% (43 bypasses) intervention rate. Primary patency rate was 43% at 3 years. Twenty-six (43%) of 61 lesions identified and repaired met criteria for PTA; the remaining 35 graft lesions (stenosis, n = 30; vein graft aneurysm, n = 5) were surgically corrected with vein patch angioplasty (n = 15), interposition grafting (n = 13), jump graft bypass (n = 6), or open repair (n = 1). At 3 years the assisted primary patency rate was 91% (7 graft failures). Multiple interventions were performed in 18 (42%) revised grafts because of metachronous (n = 6) or repair site stenosis (n = 12). In 18 graft interventions (PTA, n = 9; surgery, n = 9) recurrent stenosis developed, and endovascular therapy was used in one third (n = 6). At 3 years the stenosis-free patency rate for PTA (48%) and surgically repaired (53%) graft lesions was similar. CONCLUSIONS: Arm veins used in lower limb bypass procedures are prone to development of stenosis and aneurysm, lesions easily detected with a life-long duplex ultrasound surveillance program. Excellent long-term patency (91%) was achieved despite graft intervention being performed in nearly half of all bypasses and one third of revised grafts. Endovascular treatment was possible in half of all graft stenosis, with outcomes similar to those with surgical repair.

Aged↗
PubMed2004

Long-term survival after vascular surgery: specific influence of cardiac factors and implications for preoperative evaluation.

OBJECTIVE: We sought to identify specific determinants of long-term cardiac events and survival in patients undergoing major arterial operations after preoperative cardiac risk stratification by American College of Cardiology/American Heart Association guidelines. A secondary goal was to define the potential long-term protective effect of previous coronary revascularization (coronary artery bypass grafting [CABG] or percutaneous coronary intervention [PCI]) in patients with vascular disease. METHODS: Four hundred fifty-nine patients underwent risk stratification (high, intermediate, low) before 534 consecutive elective or urgent (<24 hours after presentation) open cerebrovascular, aortic, or lower limb reconstruction procedures between August 1996 and January 2000. Long-term follow-up (mean, 56 +/- 14 months) was possible in 97% of patients. The Kaplan-Meier method was used for survival data. Long-term prognostic variables were identified with the multivariate Cox proportional hazards model and contingency table analysis censoring early (<30 days) perioperative deaths. RESULTS: While 5-year survival was 72% for the overall cohort, cardiac causes accounted for only 24% of all deaths, and new cardiac events (myocardial infarction, congestive heart failure, arrhythmia, unstable angina, new coronary angiography, new CABG or PCI, cardiac death) affected only 4.6% of patients per year during follow-up. High cardiac risk stratification level (hazards ratio [HR], 2.2, 95% confidence interval [CI], 1.4-3.4), adverse perioperative cardiac events (myocardial infarction, congestive heart failure, ventricular arrhythmia; HR, 2.2; 95% CI, 1.2-4.1), and age (HR, 0.33; 95% CI, 0.2-0.6) were independently prognostic for latemortality. Preoperative cardiac risk levels also correlated with new cardiac event rates ( P < .01) and late cardiac mortality ( P = .02). Modestly improved survival in patients who had undergone CABG or PCI less than 5 years before vascular operations compared with those who had undergone revascularization 5 or more years previously and those at high risk without previous coronary intervention (73% vs 58% vs 62% 5-year survival; P = .02) could be demonstrated with univariate testing, but not with multivariate analysis. Type of operation, urgency, noncardiac complications, and presence of diabetes did not affect long-term survival. CONCLUSION: Despite cardiac events being a less common cause of late mortality after vascular surgery, perioperative cardiac factors (age, preoperative risk level, early cardiac complications) are the primary determinants of patient longevity. Patients undergoing more recent (<5 years) CABG or PCI before vascular surgery do not have an obvious survival advantage compared with patients at high cardiac risk without previous coronary interventions.

Adult↗
PubMed2003

Evolving complexity of open aortofemoral reconstruction done for occlusive disease in the endovascular era.

Available endovascular and less invasive surgical interventions have diminished the need for aortofemoral bypass (AFB) construction for chronic inflow occlusive disease but have potentially increased its complexity. We reviewed our results with AFB done in 107 consecutive patients between 1997 and June 2002 (83 men, 24 women, mean age 62 +/- 7 years) with chronic limb ischemia due to aortoiliofemoral occlusive disease. Perioperative factors and surgical outcomes (<30 days) were evaluated and compared between patients requiring complex (redo AFB, need for visceral aortic clamp for juxtarenal occlusion, adjunctive visceral revascularization, or simultaneous inflow/outflow bypass) and conventional reconstructions by contingency table analysis. AFB was done for limb threat in 65 patients (61%) and 44 patients (41%) had failed previous inflow procedures (22 endovascular, 43 open; 1.5/patient). Operative complexity (36 patients, 34%) was evidenced by the need for redo AFB in 8 patients, suprarenal (13) or supramesenteric/celiac (6) aortic clamp and pararenal endarterectomy in 19 cases, adjunctive renal (10) or mesenteric (2) revascularization, or simultaneous construction of AFB and femoropopliteal/tibial bypasses in 9 patients. Overall AFB operative mortality and major complication rates were 3.7% ( n = 4) and 34% ( n = 36), respectively. Mortality ( p = 0.32) and nonvisceral related complications ( p = 0.3) were not statistically more frequent after complex AFB (5.6%, 31%) than after conventional reconstructions (2.8%, 21%). However, renal, mesenteric, or spinal cord (visceral) ischemic complications or death (10.3%) were greater after complex reconstructions (19.4%) than after conventional AFB (5.6%) ( p = 0.03). Pre-existing renal insufficiency (Cr >/=1.5, n = 9) was not predictive of postoperative renal failure (>2x preop Cr, n = 7) in this series ( p = 0.4). Our recent experience with AFB suggests its increasing use as a tertiary modality after failed endovascular or less invasive open reconstructions. Despite the added operative complexity associated with manipulation of the visceral aorta and its branches and the need for extended infrainguinal revascularization, satisfactory clinical outcomes can be achieved.

Aorta, Abdominal↗
PubMed2003

Vascular injuries associated with elective orthopedic procedures.

The objective of this study was to review the diagnosis, management, and outcome of the rare iatrogenic arterial injury associated with elective orthopedic joint procedures. A retrospective review was conducted of all patients presenting to the vascular surgery service with arterial injury after elective orthopedic procedures between 1997 and 2002. Clinical records were reviewed for presentation, type of injury, management, and outcome. During the study period, 20 patients having 21 total orthopedic procedures were identified with 27 arterial injuries. There were 4350 elective orthopedic procedures during this period for an incidence of 0.005%. There were 14 total knee arthroplasties, 4 total hip arthroplasties, and 3 ankle reconstructions in the study group. Presenting signs included acute ischemia with loss-of-limb Doppler-detected arterial flow/pulses (13 patients, 62%), intraoperative arterial bleeding (3 patients, 14%), nonhealing wounds (3 patients, 14%), and limb edema (2 patients, 10%); the diagnosis was delayed >24 hr in 5 patients (25%). Arterial thrombosis was the most common abnormality identified (21 of 27 injuries, 78%), followed by laceration/avulsion (3 injuries, 11%) and pseudoaneurysm development (3 patients, 11%), and involved the iliac ( n = 3), common femoral ( n = 2), profunda ( n = 1), superficial femoral ( n = 4), popliteal ( n = 12), or tibial ( n = 5) arteries. Concomitant popliteal venous injury was present in one patient. Injured arterial segments had preexisting atherosclerotic disease (33%) and 15 patients (71%) had prior surgery in proximity to the arterial injury while an additional 9 (43%) had prior traumatic injury (7 [78%] of whom had revision orthopedic surgery as well). Management consisted of vein bypass grafting ( n = 15, 56%), primary repair ( n = 3, 11%), and thrombectomy with thrombolysis ( n = 2, 7%). One patient (5%) underwent primary above-knee amputation. There was one death from septic shock and there were three limb losses (14%). Arterial injury associated with elective orthopedic joint surgery is more common during redoprocedures and in patients with preexisting atherosclerosis. Despite arterial repair/bypass, limb morbidity is common and related to preexisting occlusive disease or extent of arterial thrombosis.

Aged↗
PubMed2003

Patency of infrarenal aortic side branches determines early aneurysm sac behavior after endovascular repair.

In this study we sought to determine whether initial abdominal aortic aneurysm (AAA) sac anatomy, morphology, and side branch patency influence changes in aneurysm size and development of endoleak following endovascular repair. A blinded, retrospective review of preintervention CT scans and angiograms was conducted on 70 consecutive patients treated for infrarenal AAA (mean size 6.0 +/- 0.8 cm) by AneuRx stent-graft exclusion. Initial AAA diameter and side branch (inferior mesenteric artery [IMA], lumbar artery pair) patency, AAA clot/sac diameter ratio, wall thrombus and calcification distributions, attachment site anatomy, endograft size, and other clinical parameters were correlated with postoperative persistent side branch patency, presence of type II endoleak, and change in AAA diameter (increase/decrease ? 5 mm) using contingency table analyses. Patients underwent CT scanning and/or color duplex imaging at 1 month and at 3 (with endoleak) or 6 (without) month intervals postoperatively with 50 patients followed beyond 6 months (mean follow-up 11 +/- 7 months). The majority of patients possessed patent side branches prior to intervention (lumbar [n = 60, 86%], IMA [n = 45, 64%]). Development of type II endoleak or persistence of side branches could not be predicted (p > 0.05) from preoperative AAA side branch patency or any of the other initial anatomic AAA variables. On serial post-repair CT or duplex cans, 42% (19/45) of IMAs and 27% (16/60) of lumbar artery pairs remained patent. For patients followed beyond 6 months, type II endoleaks persisted in half (13/25) of the patients with patent side branches with roughly equal proportions fed by IMA and lumbar sources. Persistent side branches or presence of type II endoleak was associated with AAA expansion or the failure of aneurysm size diminution after endografting (p <0.01). Aneurysm sac regression was most likely in the absence of endoleak and patent side branches. We conclude that persistent side branch patency not only fuels development of type II endoleak but also influences early aneurysm sac behavior after endovascular repair. Optimal anatomic patient selection for endografting may not be possible on the basis of our initial experience, since preoperative AAA variables did not predict persistence of side branches or type II endoleaks.

Aged↗
PubMed2003

Magnetic resonance angiography minimizes need for arteriography after inadequate carotid duplex ultrasound scanning.

PURPOSE: We prospectively evaluated whether magnetic resonance angiography (MRA) enabled definition of cerebrovascular anatomy after indeterminate or inadequate results at duplex ultrasound scanning to facilitate patient selection for carotid endarterectomy (CEA) and for technical planning. METHODS: After implementation of a protocol in October 1998 to minimize use of cerebral arteriography, MRA (arch/cervical two-dimensional and cranial three-dimensional time of flight technique) was performed in 138 consecutive patients with cerebrovascular occlusive disease and inconclusive duplex scans obtained by an ICAVL-approved laboratory. The ability of MRA to define anatomic features unresolved at duplex scanning was compared between categories of duplex scan inadequacies. Operative outcome was compared between patients requiring MRA before CEA (n = 66) and a concurrent cohort undergoing CEA on the basis of duplex scan results only (n = 69). RESULTS: Incomplete imaging of the carotid bifurcation, because of high bifurcation, long (>3 cm) internal carotid artery (ICA) plaque, or calcific shadows, was the most common reason for inadequate duplex scans (n = 74, 53%), followed by borderline severe ICA disease (23.17%), suspected extracervical disease (supra-aortic trunk, vertebral, or intracranial, 22, 16%), ICA near- occlusion (12.9%), and diffuse recurrent stenosis (7.5%). MRA enabled resolution of duplex scan inadequacies in 95% of patients with disease confined to the carotid bifurcation, and 90% of all patients, but was least accurate for delineation of extracervical lesions (77%) and near-occlusions (75%). In 5 of 8 patients (6%) arteriography was performed to determine operability of ICA near-occlusion or extracervical lesions. Combined stroke and death rates after CEA were not statistically different (P =.3) between patients requiring MRA (3 of 66, 4.6%) and the concurrent group in whom MRA was performed solely on the basis of duplex results (1 of 69, 1.5%). However, intraoperative technical adjustments (anatomy that precluded shunt use, extended endarterectomy length, ICA shortening due to tortuosity) were planned in 71% of patients (12 of 17) with MRA-defined anatomy, but only 36% of patients (4 of 11) with long CEA on the basis of duplex results only (P =.08). CONCLUSION: MRA replaces the need for cerebral arteriography in most patients after inadequate carotid duplex scanning. Delineation of cerebrovascular anatomy at MRA assists in determination of CEA candidacy and operative planning.

Aged↗
PubMed2003

Outcome of carotid stent-assisted angioplasty versus open surgical repair of recurrent carotid stenosis.

PURPOSE: We compared outcome and durability of carotid stent-assisted angioplasty (CAS) with open surgical repair (ie, repeat carotid endarterectomy [CEA]) to treat recurrent carotid stenosis (RCS). METHODS: A retrospective review of anatomic and neurologic outcomes was carried out after 27 repeat CEA procedures (1993-2002) and 52 CAS procedures (1997-2002) performed to treat high-grade internal carotid artery (ICA) RCS after CEA. The incidence of intervention because of symptomatic RCS was similar (repeat CEA, 63%; CAS, 60%), but the interval from primary CEA to repeat intervention was greater (P <.05) in the repeat CEA group (83 +/- 15 months) compared with the CAS group (50 +/- 8 months). In the CAS group, 17 of 52 arteries (33%) were judged not to be surgical candidates because of surgically inaccessible high lesions (n = 8), medical comorbid conditions (n = 4), neck irradiation (n = 3), or previous surgery with cranial nerve deficit or stroke (n = 2). Three patients who underwent repeat CEA had lesions not appropriate for treatment with CAS. RESULTS: Overall 30-day morbidity was similar after CAS (12%; death due to ipsilateral intracranial hemorrhage, 1; nondisabling stroke, 1; reversible neurologic deficits or transient ischemic attack, 2; access site complication, 2). and repeat CEA (11%; no death; nondisabling stroke, 1; reversible cranial nerve injury, 1; cervical hematoma, 1). Combined stroke and death rate was 3.7% for repeat CEA and 5.7% for CAS (P >.1). All duplex ultrasound scans obtained within 3 months after CEA and CAS demonstrated patent ICA and velocity spectra of less than 50% stenosis. During follow-up, no repeat CEA (mean, 39 months) or CAS (mean, 26 months) repair demonstrated ICA occlusion, but two patients (8%) who underwent repeat CEA and 4 patients (8%) who underwent CAS required balloon or stent angioplasty because of 80% RCS. At last follow-up, no patient had ipsilateral stroke and all ICA remain patent. At duplex scanning, stenosis-free (<50% diameter reduction) ICA patency at 36 months was 75% after repeat CEA and 57% after CAS (P =.26, log-rank test). CONCLUSIONS: Carotid angioplasty for treatment of high-grade stenotic ICA after CEA resulted in similar anatomic and neurologic outcomes compared with open surgical repair. Most lesions are amenable to endovascular therapy, and CAS enabled treatment in patients judged not to be suitable surgical candidates. Duplex scanning surveillance after repeat CEA or CAS is recommended, because stenosis can recur after either secondary procedure.

Adult↗
PubMed2003

The effects of dichloroacetate in a rabbit model of acute hind-limb ischemia and reperfusion.

BACKGROUND: Dichloroacetate (DCA) is a drug that allows pyruvate dehydrogenase to remain active under anaerobic conditions by inhibiting the inactivating enzyme, pyruvate dehydrogenase kinase. We hypothesize that the administration of DCA during acute limb ischemia may have a beneficial effect by reducing the severity of anaerobic metabolism and lessening the irreversible injury. STUDY DESIGN: We studied a rabbit model using unilateral ligation of the iliac artery or femoral artery to evaluate two degrees of ischemia. After 2 hours of hind-limb ischemia, the animals were administered IV DCA (15 mg/kg) or an equivalent volume of saline. RESULTS: Higher serum lactate levels were seen after high compared to low ligation in control animals consistent with more severe ischemia. DCA treatment significantly reduced serum lactate levels after both high and low ligation. Similarly, the rise in percentage end-tidal CO(2) after reperfusion was less after DCA. All animals regained hind-limb function after the procedure, but ischemia or reperfusion resulted in appreciable muscle necrosis (> 10% area) in 50% of high- and 22% of low-ligation control animals. DCA treatment eliminated significant muscle necrosis in 100% of high-ligation animals. Muscle histology was similar in control and DCA-treated low-ligation animals. CONCLUSIONS: Treatment with DCA during acute arterial occlusion did significantly lower markers of anaerobic metabolism and reduced muscle necrosis in a rabbit model of acute hind-limb ischemia. DCA delivery through collateral blood flow may prolong the ischemia time interval before the onset of irreversible muscle injury and potential limb loss.

Animals↗