Chandu Vemuri

Supraclavicular decompression for neurogenic thoracic outlet syndrome in adolescent and adult populations

OBJECTIVE This study was conducted to better define clinical results and understand factors determining responsiveness to surgical treatment for neurogenic thoracic outlet syndrome (NTOS) in adolescent and adult populations. METHODS A retrospective review was conducted for 189 patients with disabling NTOS who underwent primary supraclavicular decompression (scalenectomy, brachial plexus neurolysis and first rib resection, with or without pectoralis minor tenotomy) from April 2008 to December 2010. Clinical characteristics were compared between 35 adolescent patients (aged<21 years) and 154 adults (aged>21 years). Functional outcome measures were assessed before surgery and at 3- and 6-month follow-up using a composite NTOS Index combining the Disabilities of the Arm, Shoulder and Hand (DASH) survey, the Cervical-Brachial Symptom Questionnaire (CBSQ), and a 10-point visual analog scale (VAS) for pain. RESULTS Adolescent and adult patients were not significantly different with respect to sex (overall 72.5% female), side affected (58.7% right, 60.3% dominant limb), bony anomalies (23.3%), previous injury (55.6%), coexisting pain disorders (11.1%), and positive responses to scalene muscle anesthetic blocks (95.6%). Compared with adults, adolescent patients had a significantly (P<.05) lower incidence of depression (11.4% vs 41.6%), motor vehicle injury (5.7% vs 20.1%), previous operations (11.4% vs 29.9%), preoperative use of opiate medications (17.1% vs 44.8%), and symptom duration>2 years (24.2% vs 50.0%). Mean preoperative NTOS Index (scale 0-100) was significantly lower in adolescent vs adult patients (46.5±3.6 vs 58.5±1.7; P=.009), and hospital length of stay was 4.4±0.2 vs 4.9±0.1 days (P=.03), but the rate of postoperative complications was no different (overall, 4.2%). Although both groups exhibited significant improvement in functional outcome measures at 3 and 6 months, adolescent patients had significantly lower NTOS Index (10.4±3.1 vs 39.3±3.3; P<.001) and use of opiate medications (11.4% vs 47.4%; P<.001) compared with adults. CONCLUSIONS Adolescents undergoing supraclavicular decompression for NTOS had more favorable preoperative characteristics and enhanced 3-month and 6-month functional outcomes than adults. Further study is needed to delineate the age-dependent and independent factors that promote optimal surgical outcomes for NTOS.

Postapproval outcomes of juxtarenal aortic aneurysms treated with the Zenith fenestrated endovascular graft

OBJECTIVE The objective of this study was to evaluate postapproval outcomes of patients with juxtarenal aortic aneurysms treated with the Zenith fenestrated endovascular graft (Cook Inc, Bloomington, Ind). METHODS We reviewed clinical data of consecutive patients treated with the Zenith fenestrated endovascular graft in the United States at seven institutions with early commercial access from July 2012 to December 2012. Clinical outcomes and compliance to anatomic guidelines were compared with results of the U.S. fenestrated trial (USFT). RESULTS Fifty-seven patients were treated. There were significantly more (P < .05) patients with coronary artery disease, myocardial infarction, and preoperative renal insufficiency than in the USFT. Thirty-six patients (63.2%) did not meet the USFT anatomic criteria of a >4-mm infrarenal neck, and there were significantly more mesenteric stents (13 vs 0; P < .05) used in this group than in the USFT, reflecting the higher anatomic complexity of these patients. The total operative time was 250.2 ± 14.8 minutes, the fluoroscopy time was 68.9 ± 4.47 minutes, and the average volume of contrast material was 108.6 ± 5.6 mL. Technical success was 100% in regard to aneurysm exclusion, although the left renal fenestration was not able to be aligned in two patients, and one patient had a kinked renal stent that was successfully restented. During this time period, there were a total of 10 endoleaks, of which two were type III and eight were type II. CONCLUSIONS Despite higher rates of comorbidities and more challenging anatomy, early 30-day outcomes of juxtarenal aortic aneurysms treated postapproval with the Zenith fenestrated endovascular graft compare well with USFT data. Future studies are needed to assess durability of this treatment modality as the technology diffuses and data mature.

Early effectiveness of isolated pectoralis minor tenotomy in selected patients with neurogenic thoracic outlet syndrome

OBJECTIVE This study evaluated the early effectiveness of isolated pectoralis minor tenotomy (PMT) in the surgical treatment of selected patients with neurogenic thoracic outlet syndrome (NTOS) compared with supraclavicular decompression (SCD; as scalenectomy, neurolysis, and first rib resection) plus PMT (SCD+PMT). METHODS Data were obtained for 200 patients undergoing operative treatment for disabling NTOS between 2008 and 2011. Isolated PMT was offered to 57 patients with physical examination findings limited to the subcoracoid space, and SCD+PMT was offered to 143 with scalene triangle and subcoracoid findings. Functional outcomes were assessed before and 3 months after surgery using the Disabilities of the Arm, Shoulder and Hand (DASH) survey and related instruments. RESULTS There were no significant differences (P > .05) between PMT and SCD+PMT patients with respect to age (overall, 37 ± 1 years), sex (73% women), side affected (52% right, 14% bilateral), or the frequency of various NTOS symptoms, but fewer PMT patients had a bony anomaly (0% vs 18%; P < .01) or a history of injury (35% vs 61%; P < .01). Mean preoperative DASH scores were similar between PMT and SCD+PMT groups (49.9 ± 3.6 vs 50.8 ± 1.6), but previous use of opiate pain medications was higher in PMT patients (47% vs 20%; P = .0004). PMT was conducted as an outpatient procedure, whereas the mean hospital stay after SCD+PMT was 4.8 ± 0.1 days, with two patients (1%) requiring early reoperations for persistent lymph leaks. Mean DASH scores 3 months after surgery were significantly improved after isolated PMT (29.6 ± 4.2; P < .01) and SCD+PMT (41.5 ± 2.2; P < .01), but the mean extent of improvement in DASH scores was not significantly different in PMT (32% ± 9%) vs SCD+PMT (19% ± 5%). There were also no significant differences in the proportion of PMT vs SCD+PMT patients demonstrating improvement in functional outcome measures (75% vs 72%) or in overall use of opiate medications (35% vs 27%). CONCLUSIONS Isolated PMT is a low-risk outpatient procedure that is effective for the treatment of selected patients with disabling NTOS, with early outcomes similar to SCD+PMT. These findings emphasize the importance of recognizing subcoracoid brachial plexus compression as part of the spectrum of NTOS and support the role of PMT in surgical management.

Antithrombin nanoparticles improve kidney reperfusion and protect kidney function after ischemia-reperfusion injury

In the extension phase of acute kidney injury, microvascular thrombosis, inflammation, vasoconstriction, and vascular endothelial cell dysfunction promote progressive damage to renal parenchyma after reperfusion. In this study, we hypothesized that direct targeting and pharmaceutical knockdown of activated thrombin at the sites of injury with a selective nanoparticle (NP)-based thrombin inhibitor, PPACK (phenylalanine-proline-arginine-chloromethylketone), would improve kidney reperfusion and protect renal function after transient warm ischemia in rodent models. Saline- or plain NP-treated animals were employed as controls. In vivo 19F magnetic resonance imaging revealed that kidney nonreperfusion was evident within 3 h after global kidney reperfusion at 34 ± 13% area in the saline group and 43 ± 12% area in the plain NP group and substantially reduced to 17 ± 4% (∼50% decrease, P < 0.05) in the PPACK NP pretreatment group. PPACK NP pretreatment prevented an increase in serum creatinine concentration within 24 h after ischemia-reperfusion, reflecting preserved renal function. Histologic analysis illustrated substantially reduced intrarenal thrombin accumulation within 24 h after reperfusion for PPACK NP-treated kidneys (0.11% ± 0.06%) compared with saline-treated kidneys (0.58 ± 0.37%). These results suggest a direct role for thrombin in the pathophysiology of AKI and a nanomedicine-based preventative strategy for improving kidney reperfusion after transient warm ischemia.

The effect of extremity vascular complications on the outcomes of cardiac support device recipients

OBJECTIVE To assess the effect of extremity vascular complications (EVCs, including ischemia or vessel trauma) on the outcomes of patients receiving cardiac support devices (CSDs, including ventricular assist device [VAD] and extracorporeal membrane oxygenation [ECMO]). METHODS Institutional Review Board-approved, retrospective review of a prospectively maintained database of all temporary and permanent CSD recipients from 7/1/10 to 6/30/12. Patient demographics, procedural data, and outcomes were analyzed. The primary endpoint was all-cause mortality at 30-days post-CSD initiation. RESULTS Of 208 patients who received CSDs, 31 (14.9%) experienced EVC: 13 (8.9%) of the 146 permanent VADs, 10 (26.3%) of the 38 temporary VADs, and 8 (33.3%) of the 24 ECMO patients. The 30-day mortality for CSD-EVC patients was not significantly higher than that of the CSD patients who did not experience EVC for permanent VAD (15.4% vs 4.5%; P = .15) and ECMO patients (50.0% vs 68.75%; P = 1.00), but was significantly higher for temporary VAD patients (80.0% vs 35.7%; P = .03). Within the CSD-EVC cohort, patients who received a temporary VAD had a significantly higher 30-day mortality and decision to withdraw care after EVC compared with those who received a permanent VAD (P = .01 and P < .01, respectively). Looking beyond the 30-day window, EVC was associated with higher mortality rates in the permanent VAD population (53.8% vs 25.6%; P = .025) but not the temporary VAD or ECMO groups. CONCLUSIONS In temporary VAD recipients, EVCs result in higher 30-day mortality, more frequent withdrawal of care, and shortened survival time relative to the global temporary VAD group. EVC in permanent VAD recipients did not affect early (30-day) mortality rates, but strongly predicted a higher cumulative mortality risk for the 2-year study period. Overall ECMO mortality rates were high, and not significantly impacted by the occurrence of EVC. The nature of the EVC (cannulation site complication vs embolic injury) did not impact mortality. This data provides quality improvement targets for VAD programs.

Associations between clinical diagnostic criteria and pretreatment patient-reported outcomes measures in a prospective observational cohort of patients with neurogenic thoracic outlet syndrome

Objective: Neurogenic thoracic outlet syndrome (NTOS) is caused by dynamic compression of the brachial plexus at the level of the supraclavicular scalene triangle or the subcoracoid (pectoralis minor) space, or both. The purpose of this study was to characterize relationships between 14 clinical diagnostic criteria (CDC) and seven pretreatment patient‐reported outcomes measures (PROMs) in a prospective cohort of patients with NTOS. Methods: There were 183 new patient referrals between July 1 and December 31, 2015, with 150 (82%) meeting an established set of predefined CDC for NTOS. PROMs were evaluated across five domains: pain severity, functional disability, depression, quality of life, and pain catastrophizing. Linear regression and Pearson correlation statistics were used to analyze associations between CDC and PROMs. Results: Mean ± standard error patient age was 37.1 ± 1.1 years (range, 12‐66 years), and 107 (71%) were women. Five (3%) had a cervical rib, and 15 (10%) had recurrent NTOS. The most frequently positive CDC were neck or upper extremity pain (99%), upper extremity or hand paresthesia (94%), symptom exacerbation by arm elevation (97%), localized supraclavicular or subcoracoid tenderness to palpation (96%), and a positive 3‐minute elevated arm stress test (94%; mean duration, 102.0 ± 5.1 seconds). The number of positive CDC (mean, 9.6 ± 0.1) correlated with the degree of tenderness to palpation and the duration of elevated arm stress test, as well as with PROMs for pain severity, functional disability, depression, physical quality of life, and pain catastrophizing (all P < .0001). PROMs across multiple domains were also strongly correlated with each other. Patients with clinically significant pain catastrophizing exhibited a greater level of functional disability than noncatastrophizing patients (P < .0001). Conclusions: This study illustrates the relative strengths of 14 CDC and seven PROMs to evaluate patients with NTOS, helping validate the selected CDC and highlighting the potential role of pain catastrophizing in functional disability. This cohort will provide valuable information on the utility of different CDC and PROMs to predict treatment outcomes.

Clinical presentation and management of arterial thoracic outlet syndrome

Objective: Arterial thoracic outlet syndrome (TOS) is a rare condition characterized by subclavian artery pathology associated with a bony abnormality. This study assessed contemporary clinical management of arterial TOS at a high‐volume referral center. Methods: A prospectively maintained database was used to conduct a retrospective review of patients undergoing primary or reoperative treatment for arterial TOS during an 8‐year period (2008 to 2016). Presenting characteristics, operative findings, and clinical and functional outcomes were evaluated. Results: Forty patients underwent surgical treatment for arterial TOS, representing 3% of 1401 patients undergoing operations for all forms of TOS during the same interval. Patients were a mean age of 40.3 ± 2.2 years (range, 13‐68 years), and 72% were women. More than half presented with upper extremity ischemia/emboli (n = 21) or posterior stroke (n = 2), including eight that had required urgent brachial artery thromboembolectomy. The presentation in 17 (42%) was nonvascular, with 11 having symptoms of neurogenic TOS and six having an asymptomatic neck mass or incidentally discovered subclavian artery dilatation. All patients underwent thoracic outlet decompression (25 supraclavicular, 15 paraclavicular), of which there were 30 (75%) with a cervical rib (24 complete, 6 partial), 5 with a first rib abnormality, 4 with a clavicle fracture, and 1 (reoperation) with no remaining bone abnormality. Subclavian artery reconstruction was performed in 70% (26 bypass grafts, 1 patch, 1 suture repair), and 30% had mild subclavian artery dilatation (<100%) requiring no arterial reconstruction. Mean postoperative length of stay was 5.4 ± 0.6 days. During a mean follow‐up of 4.5 ± 0.4 years (range, 0.9‐8.1 years), subclavian artery patency was 92%, none had further dilatation or embolism, and chronic symptoms were present in six (4 postischemic/vasospasm, 2 neurogenic). Functional outcomes measured by scores on the 11‐item version of the Disability of the Arm, Shoulder and Hand Outcome Measure improved from 39.1 ± 3.8 to 19.2 ± 2.7 (P < .0001). Conclusions: This relatively large single‐institution series demonstrates the diverse clinical presentation of arterial TOS coincident with a spectrum of bony and arterial pathology. Current surgical protocols can achieve excellent outcomes for this rare and often complicated condition.

Oximetric angiosome imaging in diabetic feet

To develop a noncontrast oximetric angiosome imaging approach to assess skeletal muscle oxygenation in diabetic feet.

VS5. Operative Management of Venous Thoracic Outlet Syndrome

and associated access maturation rates within a well-defined cohort. Methods: The Hemodialysis Fistula Maturation (HFM) study is a multicenter, National Institutes of Health-funded, prospective cohort study designed to identify predictors of autogenous arteriovenous (AVF) access maturation. Symptoms and interventions for ARHI were documented during routine follow-up, and participants who received interventions for ARHI were compared with other cohort members using a nested case-control study design. Controls were matched on age (65 years), gender, AVF location (forearm, upper arm), and diabetes. The associations of ARHI with preoperative clinical, ultrasound, and vascular function measurements were evaluated using conditional logistic regression. The association of ARHI with clinical AVF maturation was assessed in the full HFM cohort by odds ratio (OR) and Pearson c test. Results: Median follow-up for the 602 HFM participants was 2.1 years (10th-90th percentiles: 0.7-3.5 years). Symptoms of ARHI occurred in 45 participants (7%), and intervention was required in 26 (4%), 58% of those with symptoms. Interventions included distal revascularization with interval ligation in 13, ligation in 7, banding in 4, revision using distal inflow in 1, and proximalization of arterial inflow in 1. Interventions were performed 30 days in 16 of 26 (63%) relative to the time of AVF construction (Fig). A history of coronary artery disease (OR, 2.60; 95% confidence interval [CI], 1.03-6.58), higher preoperative venous capacitance (per %/10 mm Hg: OR, 2.76; 95% CI, 1.07-6.52), female gender (OR, 3.17; 95% CI, 1.27-7.91), and history of diabetes (OR, 13.62; 95% CI, 1.81-102.4) were associated (P < .05) with intervention for ARHI, while a lower carotid-femoral pulse-wave velocity, and larger preoperative outflow vein diameter approached significance (P < .10). Intervention for ARHI did not significantly impact the rate of AVF maturation failure (OR, 1.54; 95% CI, 0.67-3.55; P 1⁄4 .30). Conclusions: Intervention for ARHI after AVF construction is uncommon. Both clinical and demographic factors were associated with an increased risk of intervention. The higher-risk patient populations identified should be counseled preoperatively and their operative plan designed to reduce the risk of ARHI and the need for intervention.