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Scholarly Works (13 results)

  • Article
  • Peer Reviewed
UCLA Previously Published Works (2023)

Background

Thoracic outlet syndrome (TOS) is an infrequent condition which results in disability in use of upper extremity. While TOS is often associated with manual labor, industrial workers, and accidents, it has not been reported in a physician (MD) population. Given the investment of time and effort in training to become a MD, the impact of TOS may be devastating. Our objective is to report the presentation and outcome of TOS in MDs.

Methods

A prospectively surgical database was reviewed for MDs who sought care of disabling TOS between 1997 and 2022. Demographic, clinical, outcome and pathological data were reviewed. Outcomes were assessed based on Somatic Pain Scale (SPS), Quick Disabilities of Arm, Shoulder and Hand (DASH) scores, and Derkash scores. Results were also assessed based on return to employment.

Results

A total of 19 MDs were identified, from 1,687 TOS cases. The group included 13 (63%) men, 6 (31%) women, average age 45 years (range 27-57). Presentations included 1 (5.3%) arterial TOS (ATOS), 9 (47.4%) venous TOS (VTOS), and 9 (47.4) neurogenic TOS (NTOS). All patients were right-handed, and symptomatic side was dominant hand in 7 (37%) patients. Etiologies included repetitive motion injury, athletic injury, and congenital bony abnormalities. Repetitive motion was associated with 3/9 (33%) NTOS. Significant athletic activities were noted in 12 of 19 (63%) MDs, including 8/9 (89%) VTOS and 4/9 (44%) NTOS. Athletic activities associated with VTOS included triathletes (2), rock climbing (1), long distance swimming (2), and weightlifting (3). Of the 9 NTOS cases, 3 were associated with weightlifting and 1 with skiing. Congenital causes included 1 (5%) abnormal first rib and 1 (5%) cervical rib. Time from symptom onset to consultation varied significantly according to diagnosis: ATOS 6 days, VTOS 97 days, and NTOS 2,335 days (P < 0.05). All underwent first rib resection (FRR), and 4 (4) patients required contralateral FRR. Time from surgery to last follow-up averaged 1,005 days (range: 37-4,535 days). On presentation, 6 patients were work disabled and 13 patients were work restricted. Following surgery, 4 MDs remained work restricted with mild to moderate symptoms. After surgery, standardized outcomes (SPS, Quick DASH, and Derkash score) improved in all metrics. All who were initially disabled returned to work without restriction. Significant non-TOS related comorbidities were present in all who had residual restriction. Return to work was documented in all.

Conclusions

Although it has not been reported, MDs are subject to developing TOS. Causes include repetitive motions, athletic injuries, and congenital bony abnormalities. Surgical decompression is beneficial with significant reduction in pain and disability. MDs are highly motivated and insightful; accordingly, they have a very high probability of successful work resumption, with all returning to their medical positions.
    Cover page: When Healing Hands Hurt: Epidemiology of Thoracic Outlet Syndrome Among PhysiciansCreative Commons 'BY' version 4.0 license
    • Article
    Research Reports (2008)
    Each year in the United States over 450,000 large trucks are involved in crashes, resulting in about 5000 fatalities and 120,000 injuries. Significantly, truck driver error is a major causal factor to truck-involved crashes. This points toward onboard monitoring as a promising means to encourage good driving behavior, it would recognizing and provide necessary feedback to correct self-induced hazardous driving situations. This is the basis for our past prototype development effort, which has produced under Task Orders 5509 and 6609 a suite of hardware on a Freightliner Century Class.This suite allows for online measurement of a set of driving characteristics which are indicators of unsafe driving behavior, with feedback given in real time to the driver, and offline to the carrier (and ultimately, back to the driver). Under this Task Order, we extended our work to detail a Field Operational Test. While that FOT began with 15 trucks, the work undertaken was expanded at US DOT’s request to consider additional teammates and a scope of over 200 trucks where the FOT could be collateral compared to the naturalistic data collection that could be accrued. We describe the original SOW, some of the transforming work in-between, then the finally-conceived FOT which in the end was submitted but not awarded to the PATH-Caltrans team.
      Cover page: Onboard Monitoring and Reporting for Commercial Vehicle Safety (OBMS) Phase II: Field Operational Test
      • Article
      • Peer Reviewed
      UCLA Previously Published Works (2021)

      Objective

      Spontaneous subclavian vein (SCV) thrombosis (Paget-Schroetter syndrome [PSS]) has been attributed to venous compression at the thoracic outlet and traditionally diagnosed using venography. Intravascular ultrasonography (IVUS) allows for a multidimensional view of vascular structures and might be more accurate in revealing venous compression. The goal of the present study was to compare venography and IVUS in patients presenting with PSS to assess the relative accuracy of each modality.

      Methods

      Patients presenting for evaluation of PSS from 2013 to 2019 were evaluated for SCV compression using venography and IVUS. Venography and IVUS measurements of stenosis were performed of the index and contralateral limbs in both neutral and stress (arm overhead) positions. The IVUS data included the SCV diameters in the anteroposterior (AP) plane, craniocaudal (CC) plane, and cross-sectional area (CSA). Stenosis was reported as the percentage of reduction from a reference point (lateral margin of the first rib) for the venography and IVUS data.

      Results

      For the 35 subjects, the average age was 35 years, 57% were women, 20% had presented with a documented pulmonary embolus, and 70% had initially been treated with thrombolysis. Venography demonstrated SCV occlusion in 3 patients (16%) with the index limb in the neutral position and in 18 patients (54%) with the limb in the stress position. The average stenosis in the index limbs was 41.5% (venography), and the average IVUS stenosis was 41.9% (CC), 61.8% (AP), and 74.5% (CSA; P < .05). A subset analysis revealed that in 10 of 35 patients (28%) in whom venography had identified no significant stenosis (average, 10%), IVUS had identified significant stenosis (33.5% CC, 54.3% AP, 68.7% CSA; P < .05).

      Conclusions

      IVUS proved more sensitive than venography in detecting significant stenosis leading to SCV thrombosis. A reduction in the CSA was the most sensitive measure of stenosis. IVUS identified significant stenosis in patients in whom venography failed to do so. The greatest utility of IVUS is in the evaluation of patients with PSS in whom venography shows no evident compression.
        Cover page: Intravascular ultrasonography provides more sensitive detection of subclavian vein stenosis than venography in patients presenting with Paget-Schroetter syndrome
        • Article
        • Peer Reviewed
        UCLA Previously Published Works (2023)

        Background

        Veterans are disproportionately affected by housing insecurity (HI), which can lead to adverse health outcomes and reduced life expectancy. We sought to examine the impact of HI on the outcomes of veterans who underwent abdominal aortic aneurysm (AAA) repair at our regional Veterans Affairs medical center.

        Methods

        Retrospective chart review was performed on patients who underwent AAA repair at our institution between January 1, 2000, and December 31, 2020. We examined medical history, procedure details, hospitalization course, and postoperative outcomes. Primary endpoints were a 30-day mortality and median survival. Secondary endpoints were hospital length of stay, readmission rate, and perioperative complications. Hypothesis testing was performed with t-test and chi-squared analysis. Survival analysis was conducted using Kaplan-Meier estimation.

        Results

        Of the 314 veterans that underwent AAA repair (mean age of 71.4 ± 7.8 years, 99.7% male) over the 21-year period, we identified 39 (12.4%) patients with a history of HI. The HI was associated with a positive smoking history (100% vs. 88.0%, P = 0.022), lower rate of hypertension diagnosis (69.2% vs. 84.0%, P = 0.024), and increased rate of surgical site infections (SSI) (10.3% vs. 1.8%, P = 0.016). The median postoperative survival was lower in the HI group (7.6 years [CI 6.0-11.2] vs. 8.9 [CI 6.9-10.3]).

        Conclusions

        HI was associated with reduced median postoperative survival, greater readmission rate, and increased risk of SSI following AAA repair.
          Cover page: Impact of Housing Insecurity on Outcomes in Abdominal Aortic Aneurysm Repair Among VeteransCreative Commons 'BY' version 4.0 license
          • Article
          Research Reports (2011)

          A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. This can offer a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.

          This report describes the design and implementation of the CACC system on two Infiniti FX-45 test vehicles, as well as the data acquisition system that has been installed to measure how drivers use the system, so that the impacts of such a system on highway traffic flow capacity and stability can be estimated. The results of quantitative performance testing of the CACC on a test track are presented, followed by the experimental protocol for on-road testing with human subjects. Finally, the results from the field testing by 16 naïve drivers are presented to show the user acceptance and quantitative measurements of how these drivers used the ACC and CACC systems, and how these systems affected their choice of car following gap.

            Cover page: Cooperative Adaptive Cruise Control: Testing Drivers’ Choices of Following Distances
            • Article
            Research Reports (2010)

            A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. This can offer a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.

            This report describes the design and implementation of the CACC system on two Infiniti FX-45 test vehicles, as well as the data acquisition system that has been installed to measure how drivers use the system, so that the impacts of such a system on highway traffic flow capacity and stability can be estimated. The results of quantitative performance testing of the CACC on a test track are presented, followed by the experimental protocol for on-road testing with human subjects. Finally, the results from the field testing by 16 naïve drivers are presented to show the user acceptance and quantitative measurements of how these drivers used the ACC and CACC systems, and how these systems affected their choice of car following gap.

              Cover page: Cooperative Adaptive Cruise Control: Testing Drivers’ Choices of Following Distances
              • Article
              Research Reports (2009)

              A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. If this is shown to be the case, it offers a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.

              This report describes the design and implementation of the CACC system on two Infiniti FX-45 test vehicles, as well as the data acquisition system that has been installed to measure how drivers use the system, so that the impacts of such a system on highway traffic flow capacity and stability can be estimated. The results of quantitative performance testing of the CACC on a test track are presented, followed by the experimental protocol to be followed for on-road testing with human subjects. Finally, the results from the first pilot test are presented to show how the data are analyzed to reveal the implications of CACC for driving behavior and user acceptance.

                Cover page: Effects of Cooperative Adaptive Cruise Control on Traffic Flow: Testing Drivers' Choices of Following Distances
                • Article
                • Peer Reviewed
                UCLA Previously Published Works (2022)

                Background

                We hypothesize among patients undergoing lower extremity amputation, access to pre-, and post operative rehabilitation services; as well as improved medical care, have led to higher rates of postoperative ambulation, and improved survival.

                Methods

                Retrospective single center review of all major lower extremity amputations performed at the Greater Los Angeles Veterans Affairs Healthcare System from 2000-2020 stratified into multiyear cohorts. We abstracted demographics, operative indication, comorbidities, preoperative medical management, perioperative complications, discharge location, and pre and postoperative ambulatory status. Odds of ambulation after amputation were analyzed using multivariate logistic regression. Survival was analyzed using multivariate logistic regression and Kaplan-Meier survival analysis. Multivariate logistic predictors were selected based on prior literature and clinical experience.

                Results

                We identified 654 operations in our study, noting fewer amputations performed in the latest 3 cohort years as compared to the initial cohort (2000-2004). Patients undergoing below-knee amputations (BKA) had 2.7 times (P < 0.05) greater odds of postoperative ambulation and 86% (P < 0.05) increased odds of survival compared to above-knee amputations (AKA). The odds of ambulation increased by 8.8% (P < 0.05) for each consecutive study year. Ambulation post-amputation conferred 13.2 times (P < 0.05) greater odds of survival. The odds of survival in "emergent" operations decreased by 48% (P < 0.05) compared to an "elective" operation. For each additional comorbidity, the odds of survival decreased by 18% (P < 0.05). Patients with any perioperative complication had a 48% (P < 0.05) lower odds of survival. Kaplan-Meier survival estimates demonstrated significant survival difference between patients by amputation level and postoperative ambulatory status (P < 0.05).

                Conclusions

                Ambulatory status following distal amputation has improved over time and is significantly associated with increased survival post-amputation. Patients undergoing a BKA or discharged home were most likely to ambulate postoperatively. Amputation level, preoperative comorbidities, and perioperative complications remain strong predictors of survival.
                  Cover page: Lower Extremity Amputations Among Veterans: Have Ambulatory Outcomes and Survival Improved?
                  • Article
                  • Peer Reviewed
                  UCLA Previously Published Works (2023)

                  Background

                  Frailty is a known risk factor for adverse outcomes following surgery and affects at least 3 of every 10 US Veterans aged 65 years and older. We designed a study to characterize the association between frailty and complications after endovascular aneurysm repair (EVAR) compared to open aneurysm repair (OAR) at our regional Veterans Affairs Medical Center.

                  Methods

                  Veterans who underwent either OAR or EVAR at our institution between January 1, 2000 and December 31, 2020 were identified. We examined medical history, procedure characteristics, perioperative complications, and frailty as measured by the 5-factor modified frailty index (mFI-5). Frailty was defined as an mFI-5 score ≥2. Primary endpoints were postoperative complications, duration of surgery, and length of hospital stay. Tests of association were performed with t-test and chi-squared analysis.

                  Results

                  Over the 21-year period, we identified 314 patients that underwent abdominal aortic aneurysm (AAA) repair with 115 (36.6%) OAR and 199 EVAR (63.4%) procedures. Patients undergoing EVAR were older on average (72.1 years vs. 70.2 years) and had a higher average mFI-5 compared to the open repair group (1.49 vs. 1.23, P = 0.036). When comparing EVAR and OAR cohorts, patients undergoing OAR had a larger AAA diameter (6.5 cm, standard deviation [SD]: 1.5) compared to EVAR (5.5 cm, SD: 1.1 P < 0.0001). Fewer frail patients underwent OAR (n = 40, 34.8%) compared to EVAR (n = 86, 43.2%), and frail EVAR patients had higher AAA diameter (5.8 cm, SD: 1.0) compared to nonfrail EVAR patients (5.3 cm, SD 1.2), P = 0.003. Among OAR procedures, frail patients had longer operative times (296 min vs. 253 min, P = 0.013) and higher incidence of pneumonia (17.5% vs. 5.3%, P = 0.035). Among frail EVAR patients, operative time and perioperative complications including wound dehiscence, surgical site infection, and pneumonia were not significantly different than their nonfrail counterparts. Overall, frail patients had more early complications (n = 55, 43.7%) as compared to nonfrail patients (n = 48, 25.5%, P = 0.001). OAR patients had higher rates of postoperative complications including wound dehiscence (7.0% vs. 0.5%, P = 0.001), surgical site infections (7.0% vs. 1.0%, P = 0.003), and pneumonia (9.6% vs. 0.5%, P=<0.0001). Open repair was also associated with overall longer average intensive care unit stays (11.0 days vs. 1.6 days, P < 0.0001) and longer average hospitalizations (13.5 days vs. 2.4 days, P < 0.0001).

                  Conclusions

                  Our findings demonstrate that frailty is associated with higher rates of adverse outcomes in open repair compared to EVAR. Patients who underwent open repair had higher rates of wound dehiscence, surgical site infection, and pneumonia, compared to those undergoing endovascular repair. Frailty was associated with larger AAA diameter in the EVAR cohort and longer operative times, with higher frequency of postoperative pneumonia in the OAR cohort. Frailty is a strong risk factor that should be considered in the management of aortic aneurysms.
                    Cover page: Frailty Among Veterans Undergoing Abdominal Aortic Aneurysm Repair
                    • Article
                    • Peer Reviewed
                    UCLA Previously Published Works (2022)

                    Introduction

                    Access to surgical service is limited by provider availability and geographic barriers. Telemedicine ensures that patients can access medical care.

                    Objective

                    The objective is to describe our use of telemedicine in delivering vascular surgery services to remote locations before and during the COVID-19 pandemic.

                    Methods

                    We conducted a retrospective chart review analyzing care delivered at six vascular surgery telemedicine clinics over a 22-month period. We examined vascular diagnoses, recommended interventions, referrals placed, and emergency department visits within 30 days of evaluation. We calculated travel distance saved for patients between their local clinic and our main hospital.

                    Results

                    We identified 94 patients and 144 telemedicine visits, with an average of 1.5 visits per patient (SD = 0.73). The most common referrals were for peripheral artery disease (20.2%) and abdominal aortic aneurysm (14.9%). Three patients were immediately referred to the emergency department due to concern for acute limb ischemia (2) or questionable symptomatic AAA (1). Telemedicine visit recommendations were distributed between no intervention (n = 30, 31.9%), medical management (n = 41, 43.6%), and surgical intervention (n = 23, 24.5%).The surgical intervention cohort was most commonly referred to arterial revascularization (n = 4), venous ablation (n = 4), and arteriovenous fistula procedures (n = 4). Fourteen patients came to our main hospital for surgery and four to local providers. Average travel distance saved per telemedicine visit was 104 miles (SD = 43.7).

                    Conclusions

                    Telemedicine provided safe, efficient care during the COVID-19 pandemic and saved patients an average of 104 travel miles per visit.
                      Cover page: Telemedicine and Vascular Surgery: Expanding Access and Providing Care Through the COVID-19 Pandemic
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