Vikram S. Kashyap

The management of severe aortoiliac occlusive disease: Endovascular therapy rivals open reconstruction

OBJECTIVE Aortobifemoral bypass (ABF) grafting has been the traditional treatment for extensive aortoiliac occlusive disease (AIOD). This retrospective study compared the outcomes and durability of recanalization, percutaneous transluminal angioplasty, and stenting (R/PTAS) vs ABF for severe AIOD. METHODS Between 1998 and 2004, 86 patients (161 limbs) underwent ABF (n = 75) or iliofemoral bypass (n = 11), and 83 patients (127 limbs) underwent R/PTAS. All patients had severe symptomatic AIOD (claudication, 53%; rest pain, 28%; tissue loss, 12%; acute limb ischemia, 7%). The analyses excluded patients treated for aneurysms, extra-anatomic procedures, and endovascular treatment of iliac stenoses. Original angiographic imaging, medical records, and noninvasive testing were reviewed. Kaplan-Meier estimates for patency and survival were calculated and univariate analyses performed. Mortality was verified by the Social Security database. RESULTS The ABF patients were younger than the R/PTAS patients (60 vs 65 years; P = .003) and had higher rates of hyperlipidemia (P = .009) and smoking (P < .001). All other clinical variables, including cardiac status, diabetes, symptoms at presentation, TransAtlantic Inter-Society Consensus stratification, and presence of poor outflow were similar between the two groups. Patients underwent ABF with general anesthesia (96%), often with concomitant treatment of femoral or infrainguinal disease (61% endarterectomy, profundaplasty, or distal bypass). Technical success was universal, with marked improvement in ankle-brachial indices (0.48 to 0.84, P < .001). Patients underwent R/PTAS with local anesthesia/sedation (78%), with a 96% technical success rate and similar hemodynamic improvement (0.36 to 0.82, P < .001). At the time of R/PTAS, 21% of patients underwent femoral endarterectomy/profundaplasty or bypass (n = 5) for concomitant infrainguinal disease. Limb-based primary patency at 3 years was significantly higher for ABF than for R/PTAS (93% vs 74%, P = .002). Secondary patency rates (97% vs 95%), limb salvage (98% vs. 98%), and long-term survival (80% vs 80%) were similar. Diabetes mellitus and the requirement of distal bypass were associated with decreased patency (P < .001). Critical limb ischemia at presentation (tissue loss, hazard ratio [HR], 8.1; P < .001), poor outflow (HR, 2; P = .023), and renal failure (HR, 2.5; P = .02) were associated with decreased survival. CONCLUSION R/PTAS is a suitable, less invasive alternative to ABF for the treatment of severe AIOD. Repair of the concomitant femoral occlusive disease is often needed regardless of open or endovascular treatment. Infrainguinal disease negatively affects the durability of the procedure and patient survival.

Repair of type IV thoracoabdominal aneurysm with a combined endovascular and surgical approach

We report an unusual case of type IV Thoracoabdominal Aneurysm (TAA) with Superior Mesenteric Artery (SMA), celiac artery, and bilateral renal artery aneurysms in a patient who underwent an earlier repair of two infrarenal Abdominal Aortic Aneurysm (AAA) ruptures. Because of the presence of the visceral artery aneurysms and the earlier operation through the retroperitoneum, standard surgical treatment via a retroperitoneal approach with an inclusion grafting technique was considered difficult. A combined surgical approach achieving retrograde perfusion of all four visceral vessels and endovascular grafting allowing exclusion of the TAA was accomplished. Complete exclusion of the aneurysm and normal perfusion of the patients viscera was documented by means of follow-up examinations at 3 and 6 months. The repair of a type IV TAA with a Combined Endovascular and Surgical Approach (CESA) allowed us to manage both the aortic and visceral aneurysms without thoracotomy or re-do retroperitoneal exposure and minimized visceral ischemia time. If the durability of this approach is confirmed, it may represent an attractive alternative in patients with aneurysmal involvement of the visceral segment of the aorta.

Renal failure after thoracoabdominal aortic surgery

PURPOSE Renal failure remains a common and morbid complication after complex aortic surgery. This study was performed to identify perioperative factors that contribute to postoperative renal failure. METHODS The perioperative outcomes of 183 patients who underwent thoracoabdominal aortic surgery with supraceliac clamping were reviewed. During the interval from Jan. 1987 to Nov. 1996, thoracoabdominal aneurysm repair was performed in 154 patients (type I, 49 patients [27%]; type II, 21 patients [11.5%]; type III, 55 patients [30%]; type IV, 29 patients [16%]), suprarenal abdominal aortic aneurysm repair in 17 patients (9%), and visceral/renal revascularization procedures in 12 patients (6.5%). Intraoperative management included thoracoabdominal aortic exposure and clamp-and-sew technique with renal artery cold perfusion whenever the renal arteries were accessible (79% of cases). RESULTS Relevant clinical features included preoperative hypertension (85%), diabetes mellitus (8%), single functioning kidney (10%), recent intravenous contrast injection (34%), renal insufficiency (creatinine level greater than 1.5 mg/dl; 24%), and emergent operation (19%). Acute renal failure, defined as both a doubling of serum creatinine level and an absolute value greater than 3.0 mg/dl, occurred in 21 patients (11.5%), of whom five required hemodialysis (2.7%). Variables associated with this complication included a preoperative creatinine level greater than 1.5 mg/dl (p = 0.004) and a total cross-clamp time greater than 100 minutes (p = 0.035). The operative mortality risk (within 30 days; 8%) was significantly increased with renal failure (odds ratio, 9.2; 95% confidence interval, 2.6 to 33; p < 0.005). CONCLUSIONS Renal failure, although uncommon in contemporary practice, greatly increases the risk of early death after thoracoabdominal aortic surgery. The overall incidence of renal failure and dialysis requirement in the present series compare favorably with those reported using other operative techniques, specifically partial left heart bypass and distal aortic perfusion. These data suggest that patients who have preoperative renal insufficiency are prone to postoperative renal failure. Furthermore, regional hypothermic perfusion and minimal clamp times are important elements in the prevention of renal failure after thoracoabdominal aortic surgery.

Endovascular treatment of stenotic and occluded visceral arteries for chronic mesenteric ischemia

PURPOSE Percutaneous angioplasty and stenting (PTAS) is emerging as a therapeutic option for patients with chronic mesenteric ischemia. This study evaluated patency and mortality, and their relationship between degree of vessel occlusion (stenotic or totally occluded), stent characteristics, and comorbidities in patients who were treated with PTAS of the visceral vessels for chronic mesenteric ischemia. METHODS A retrospective review was performed of the records of all patients who underwent PTAS of the celiac, superior mesenteric, or inferior mesenteric arteries, or both, for symptomatic chronic mesenteric ischemia between January 2001 and December 2005. Patient demographics, lesion characteristics (stenosis or occlusion), interventional details, and early and late mortality rates were recorded. Cumulative mortality and patency rates and factors associated with outcomes were determined using Kaplan-Meier method and Cox proportional hazards modeling. RESULTS Eighty-seven mesenteric vessels (57 superior mesenteric, 23 celiac, and 7 inferior mesenteric arteries) were treated in 65 patients (29 men and 36 women). Completely occluded vessels were treated in 18 patients (28%), and >60% stenosis was treated in 47 patients (72%). Mesenteric angina was the most common symptom (97%). For the entire series, the cumulative 1-year results were primary patency, 65% (95% confidence interval [CI], 50%-80%); primary assisted patency, 97% (95% CI, 92%-100%); secondary patency, 99% (95% CI, 96%-100%); and survival, 89% (95% CI, 80%-98%). All deaths occurred <or=60 days after treatment. The endovascular treatment of visceral artery occlusion was not associated with diminished patency or survival, irrespective of stent size or number. Patients requiring bowel resection were less likely to survive than those who did not (odds ratio [OR], 26; 95% CI, 3.5-192; P < .001). One-year primary patency was worse among patients with chronic obstructive pulmonary disease (OR, 3.2; 95% CI, 1.4-7.7; P = .009) or who had femoral access (OR, 3.0; 95% CI, 1.1-7.9; P = .015). CONCLUSIONS For patients with chronic mesenteric ischemia, the results of endovascular treatment of occluded mesenteric arteries are indistinguishable from those treated for stenotic vessels. Patients requiring bowel resection are less likely to survive, and those with chronic obstructive pulmonary disease or who had femoral access have higher reintervention rates.

Combined staged procedures for the treatment of thoracoabdominal aneurysms.

Purpose: To examine the efficacy of a staged approach for the treatment of thoracoabdominal aneurysms, with open visceral revascularization followed by aortic endografting, in selected patients not considered candidates for conventional surgical repair. Methods: A retrospective review was conducted of 13 consecutive patients (8 women; mean age 64 years, range 33–77) who underwent visceral bypass followed by endovascular thoracoabdominal stent-graft implantation since 1999. Three patients presented with symptomatic aneurysms and 2 with rupture. Two patients had connective tissue disorders. All patients were deemed unfit for conventional thoracoabdominal repair due to comorbid conditions. The procedures were tailored to the pathology and specific patient anatomical situation: 5 aortic dissections with aneurysmal degeneration and 8 aneurysms (5 Crawford type II, 2 type III, and 1 type IV). Results: The patients underwent retrograde visceral bypass (11 iliovisceral and 2 infrarenal aortic to visceral artery) followed by endovascular aortic relining with Zenith TX2 devices (n=7), homemade endografts (n=5), or a Talent thoracic endograft (n=1). Six patients required either a proximal or distal direct aortic repair (2 infrarenal reconstructions, 3 arch elephant trunk grafts, and 1 ascending aortic repair), while 3 patients also underwent left carotid-subclavian bypass grafting. Two patients developed paraplegia (1 following a ruptured aneurysm), and 2 patients had transient paraparetic events. Two patients had acute renal failure requiring short-term dialysis. Three patients died within 30 days; 2 late aneurysm-related deaths were noted. Three patients developed endoleaks during follow-up. Mean lengths of stay were 13 days (7–30) for the visceral bypass and 12 (3–25) for the endovascular stent-graft. In addition, remaining procedures in 8 patients required a mean of 7 days (0–14) in hospital. Conclusion: Staged endovascular and open procedures are feasible for thoracoabdominal aneurysms in patients at prohibitive risk for open thoracoabdominal reconstruction. However, this approach still carries a significant risk of perioperative mortality and morbidity. The potential for less invasive alternatives should be investigated.

Long-term follow-up of type II endoleak embolization reveals the need for close surveillance

OBJECTIVE Aneurysm growth after endovascular aneurysm repair (EVAR) in patients with type II endoleak is associated with adverse outcomes. This study evaluated the long-term success of embolization of type II endoleaks in preventing aneurysm sac growth. METHODS We retrospectively reviewed outcomes of patients who underwent infrarenal EVAR who were treated for a type II endoleak between 2000 and 2008. Computed tomography scans were evaluated for aneurysm sac growth or shrinkage from the time of treatment of the endoleak. The embolization material used, graft type, target vessel embolized, and comorbidities were evaluated for their association with sac growth or shrinkage. RESULTS Ninety-five patients underwent 140 embolization procedures. The mean time from EVAR to embolization was 26.1 ± 22.2 months, and the average increase in size of the aneurysm sac from EVAR to treatment was 0.7 × 0.5 cm. Patients underwent an average of 1.6 ± 0.8 embolization procedures after EVAR. Thirteen patients underwent initial simultaneous embolization of two targets. Embolization was with glue (61%), coils (29%), glue and coils (7%), and Gelfoam (3%; Pfizer Inc, New York, NY). No abdominal aortic aneurysms (AAA) ruptured. Eight patients (8.4%) underwent graft explant and open repair; 19 (20%) required two or more embolization procedures. There was no difference in the target vessel treated or the treatment used in halting sac expansion (>5 mm). Coil embolization alone resulted in more second procedures. The 5-year cumulative survival was 65% (95% confidence interval [CI], 52%-77%), freedom from explant was 89% (95% CI, 81%-97%), freedom from second embolization was 76% (95% CI, 66%-86%), and freedom from sac expansion >5 mm was 44% (95% CI 30%-50%). Univariable analysis identified continued tobacco use (hazard ratio [HR], 2.30; 95% CI, 1.02-5.13; P = .04) was associated with continued sac expansion, and hyperlipidemia (HR, 9.64; 95% CI, 2.22-41.86) was associated with patients requiring a second embolization procedure. CONCLUSIONS Embolization of type II endoleaks is successful early in preventing aneurysm sac growth and rupture after EVAR. However, a significant number of patients require more than one procedure, and at 5 years, many patients who underwent embolization of a type II endoleak continued to experience sac growth. Patients with hyperlipidemia who undergo coil embolization are more likely to require a second embolization procedure, and patients who smoke have a higher likelihood of AAA sac expansion after embolization. Continued long-term surveillance is necessary in this cohort of patients.

The brachial artery: A critical access for endovascular procedures

OBJECTIVE The brachial artery is often used for coronary angiography. However, data on brachial access for aortic and peripheral interventions are limited. This study evaluated our experience with brachial artery catheterization for diagnostic arteriography and endovascular interventions. METHODS Between August 2004 and August 2005, 2026 endovascular procedures were performed. Of these, 323 cases (16%) in 289 patients required brachial artery access, forming the basis for this study. Patients who underwent multiple interventions, but with a single access (ie, thrombolysis), were considered a single case. Demographic and clinical data were recorded in a database and analyzed using logistic regression analyses with generalized estimating equations and the Fisher exact test for nominal variables. RESULTS The mean age of all patients was 66.4 years, with 57% men. Brachial access was used for diagnostic purposes in 27% and for interventions including angioplasty, stenting, and thrombolysis in 73%. The use of brachial access was considered obligatory in 40%, adjunctive in 19% (ie, endovascular repair of abdominal aortic and thoracic aortic aneurysms) and preferential to femoral access in 41%. In 91% of patients, the brachial arteries were accessed percutaneously, and 9% underwent surgical cutdown for access. In patients whose brachial artery was approached percutaneously, access was achieved in all but one (99.6% technical success rate). Hemostasis after catheterization was achieved by manual compression in 89%. Operative mortality rate was 6.2% and not related to brachial artery access. Brachial access site-related complications occurred in 21 patients (6.5%). Thirteen of these 21 patients (62%) required a surgical correction, mostly for brachial artery thrombosis or pseudoaneurysm. Patients with complications were more commonly women (odds ratio [OR], 4.7; 95% confidence interval [CI], 1.68-13.26; P = .003) and had a long interventional sheath (OR, 6.7; 95% CI, 1.53-29.07; P = .012). The risk of a brachial artery complication was not associated with thrombolysis, procedure type, vascular territory treated, or the use of heparin. No upper extremity limb or finger loss occurred. CONCLUSIONS Brachial artery access is necessary for complex endovascular procedures and can be achieved in most patients safely. Postprocedural vigilance is warranted because most patients with complications will require operative correction.

The contemporary management of splenic artery aneurysms

OBJECTIVES The management of patients with splenic artery aneurysms (SAAs) is variable since the natural history of these aneurysms is poorly delineated. The objective of this study was to review our experience with open repair, endovascular therapy, and observation of SAAs over a 14-year interval. METHODS Between January 1, 1996 and December 31, 2009, 128 patients with SAAs were evaluated. Sixty-two patients underwent surgical repair (n = 13) or endovascular coil/glue ablation (n = 49), while 66 patients underwent serial observation. The original medical records and computed tomography (CT) imaging were reviewed. Statistical analyses were performed using χ(2) or Fishers exact test for categorical patient characteristics and t-test for continuous variables. Kaplan-Meier estimates for survival were calculated. Mortality was verified via the Social Security Death Index. RESULTS Patients (61 ± 11 years, 69% female) were investigated for abdominal symptoms (49%) or had the incidental finding of SAA (mean size, 2.4 ± 1.4 cm). Seven patients (5.5%) presented with rupture and were treated emergently with two perioperative mortalities (29%). Patients requiring surgical or endovascular treatment were more likely male (40% vs 21%, P = .031), younger (58 vs 64 years; P = .004), and current smokers (18% vs 5%; P = .035). Increased aneurysm calcification was associated with decreased SAA size (P = .013). The mean aneurysm size at initial diagnosis was 1.67 cm for patients undergoing observation and 3.13 cm for the treated group (P < .001). Endovascular repair was safe and durable with a mean 1.5-mm regression in SAA size over 2 years. The mean rate of growth for observed SAA was 0.2 mm/y. Ten-year survival was 89.4% (95% confidence interval: 82.0, 97.4) for all patients (observed group, 94.9%; treated group, 85.1%; P = .18). No late aneurysm-related mortality was identified. CONCLUSIONS Ruptured SAAs are lethal. Large SAAs can undergo endovascular ablation safely with durable SAA regression. Smaller SAAs (<2 cm) grow slowly and carry a negligible rupture risk.

Endovascular Management of Chronic Infrarenal Aortic Occlusion

Purpose: To review our experience with the endovascular treatment of chronic infrarenal aortic occlusion with regard to technical success and midterm patency, as well as perioperative mortality and morbidity. Methods: A retrospective review was performed of patients who presented from January 1, 2000, to December 31, 2005, with a diagnosis of chronic infrarenal aortic occlusion (TASC D) treated with endovascular techniques. In this time period, 31 patients (22 women; mean age 63 years) underwent attempted recanalization of the occluded aorta and iliac arteries. Claudication was the most common presenting symptom (14, 45%). Patients were treated solely with angioplasty and stenting or thrombolysis followed by angioplasty/stenting based on surgeon preference. Results: Technical success was 93%. The 2 failures were individual cases of wire-induced iliac artery perforation and failed access; both patients were treated with bypass grafting. Nine (29%) patients had thrombolysis prior to angioplasty. There were no perioperative deaths. Postoperative ankle-brachial indexes increased significantly from preoperative values (p<0.0001). There were 3 technical complications: 1 (3%) iatrogenic iliac artery injury and 2 (6%) perioperative limb thromboses requiring intervention. Other complications included 6 (19%) access site events and 5 (16%) episodes of acute renal dysfunction, 2 requiring permanent dialysis. Over a mean follow-up of 12 months, there was no limb loss. At 1 and 3 years, the primary/secondary patency rates were 85%/100% and 66%/90%, respectively. Conclusion: Endovascular therapy for chronic infrarenal aortic occlusion has a high technical success rate, with good midterm primary and secondary patency rates. However, renal dysfunction can occur; the etiology is likely multifactorial from contrast volumes, embolization, and/or renal arterial disease.

A Comparison of the Hemoglobin-Based Oxygen Carrier HBOC-201 to Other Low-Volume Resuscitation Fluids in a Model of Controlled Hemorrhagic Shock

BACKGROUND The ideal resuscitation fluid for military applications would be effective at low volumes, thereby reducing logistical constraints. We have previously shown that the bovine hemoglobin-based oxygen carrier HBOC-201 is an effective low-volume resuscitation fluid. The goal of this experiment was to evaluate the effectiveness of HBOC-201 in comparison with other low-volume resuscitation fluids in a swine model of controlled hemorrhagic shock. METHODS Forty-two immature female Yorkshire swine (55-70 kg) were divided into seven groups of six. Animals were hemorrhaged to a mean arterial pressure of 30 mm Hg. After 45 minutes, animals were resuscitated to a mean arterial pressure of 60 mm Hg with one of the following agents: hypertonic saline 7.5% (HTS), hypertonic saline 7.5%/Dextran-70 6% (HSD), pentastarch 6%, hetastarch 6%, or HBOC-201. Lactated Ringers (LR) solution was used as a standard resuscitation control. Another group of animals received no resuscitation. Resuscitation was continued for 4 hours. Hemodynamic variables and oxygen consumption were measured continuously. Arterial and mixed venous blood gases and serum lactate levels were measured at intervals throughout the experiment. Data were analyzed using analysis of variance with Tukeys post hoc test when appropriate. Significance was defined as p < 0.05. RESULTS Five of six animals in the no-resuscitation control group, six of six in the HTS group, and one animal in the HSD group died before completion of the study. All other animals survived to completion. Animals receiving resuscitation with HBOC-201 had significantly lower cardiac output, mixed venous oxygen saturation levels, and urinary output throughout the resuscitation period; however, there were no differences with regard to lactate, base excess, or oxygen consumption. Animals receiving HBOC-201 required significantly less fluid than any other group. CONCLUSION In this model, hypotensive resuscitation with HBOC-201 restores tissue oxygenation and reverses anaerobic metabolism at significantly lower volumes when compared with HTS, HSD, pentastarch, or hetastarch solutions. These data suggest that HBOC-201 would be an effective primary resuscitation fluid for far-forward military or rural trauma settings where logistic constraints and prolonged transport times are common. However, when HBOC-201 is administered as a primary resuscitation fluid in hypotensive protocols, common clinical markers for determining adequacy of resuscitation may not be useful.