Prosthetic outcomes after amputation and the impact of mobility level on survival.

OBJECTIVE: Lower extremity amputation continues to be necessary in a significant number of patients with peripheral vascular disease. The 5-year survival following lower limb loss is markedly reduced. Many of these patients are never fitted with a prosthesis, and there is a dearth of knowledge regarding the barriers to prosthetic attainment. The goal of this study was to identify the risk factors for not receiving a prosthesis and the effect of mobility level on survival following major amputation. METHODS: This was a retrospective analysis of all patients that underwent lower extremity amputation by surgeons in our practice from January 1, 2010, to December 31, 2019. Abstracted data included: age, sex, race, body mass index, comorbidities, American Society of Anesthesiologists score, statin use, level of amputation, stump revision, fitting for prosthesis, type of prosthesis, and the United States' Medicare Functional Classification Level, also called K level. Survival was determined using a combination of sources, including the Social Security Death Master File, searches of multiple genealogic registries, and general internet searches. Multivariable logistic regression was used to determine risk factors associated with prosthesis attainment. Multivariable Cox proportional hazard regression with time-dependent covariates was performed to assess risk factors associated with 5-year mortality. RESULTS: A total of 464 patients were included in this study. The mean age was 65 years, and mean body mass index was 27 kg/m2. The majority of patients were male (68%), White (56%), diabetic (62%), and hypertensive (76%), and underwent below-the-knee amputation (69%). Prosthetic attainment occurred in 185 (40%). On multivariable analysis, age >81 years and current tobacco use were associated with no prosthetic fitting. Overall 5-year survival was 41.9% (95% confidence interval [CI], 37.6%-46.6%) (below-the-knee amputation, 47.7% [95% CI, 42.5%-53.5%]; above-the-knee amputation, 28.7% [95% CI, 22.1%-37.2%]). On multivariable analysis, age >60 years, congestive heart failure, above-the-knee amputation, and no prosthetic attainment were associated with decreased survival. Increasing K level was incrementally associated with improved survival. CONCLUSIONS: This study has identified several patient factors associated with prosthetic attainment, as well as multiple factors predictive of reduced survival after amputation. Being referred for prosthetic fitting was associated with improved survival not explained by patient characteristics and comorbidities. The Medicare Functional Classification Level K level predicts survival. More research is needed to determine the barriers to prosthetic attainment and if improving a patients K level will improve survival.

Sex, age, and other barriers for prosthetic referral following amputation and the impact on survival.

BACKGROUND: Despite advances in peripheral vascular disease treatment, lower extremity amputation continues to be necessary in a significant number of patients. Up to 80% of amputees are not referred for prosthetic fitting. The factors contributing to referral decisions have not been adequately investigated, nor has the impact of prosthetic referral on survival. We characterized differences between patients who were successfully referred to our in-house prosthetists and those who were not, and identified factors associated with prosthetic referral and predictive of survival. METHODS: This was a retrospective analysis of all patients who underwent lower extremity amputation by surgeons in our practice from January 1, 2010, to June 30, 2017. Data regarding age, sex, race, body mass index (BMI), diabetes, hypertension, hyperlipidemia, end-stage renal disease, prior coronary artery bypass graft surgery, congestive heart failure, tobacco use, American Society of Anesthesiologists (ASA) score, previous arterial procedure, chronic obstructive pulmonary disease, statin use, postoperative ambulatory status, level of amputation, stump revision, and referral for prosthesis were collected. Survival was determined from a combination of sources, including the Social Security Death Master Index, multiple genealogic registries, and internet searches. Multivariable logistic regression was used to determine risk factors associated with prosthesis referral. Multivariable Cox proportional hazard regression with time-dependent covariates was performed to assess risk factors associated with 5-year mortality. RESULTS: There were 293 patients included in this study. Mean age was 66 years, and mean BMI 27 kg/m2. The majority of patients were male (69%), white (53%), with diabetes (65.4%) and hypertension (77.5%), and underwent below-the-knee amputation (BKA) (73%). Prosthetic referral occurred in 123 (42.0%). Overall 5-year survival was 61.7% (95% confidence interval [CI], 55.9%-68.1%) (BKA 64.7% [95% CI, 57.9%-72.3%]; above-the-knee amputation 53.8% [95% CI, 43.4%-66.6%]). On multivariate analysis, age >70 years, female sex, diabetes, ASA score 4 or 5, and current tobacco use were associated with no referral for prosthetic fitting. Patients with BMI 25 to 30, a previous arterial procedure, BKA, and history of stump revision were more likely to be referred. Factors associated with decreased survival were increasing age, higher ASA class, black race, and BMI; prosthetic referral was seen to be protective. CONCLUSIONS: We identified multiple patient factors associated with prosthetic referral, as well as several characteristics predictive of reduced survival after amputation. Being referred for prosthetic fitting was associated with improved survival not explained by patient characteristics and comorbidities. Further research is needed to determine whether the factors identified as associated with nonreferral are markers for patient characteristics that make them clinically unsuitable for prosthetic fitting or if they are symptoms of unconscious bias or of the patient's access to care.

Ensuring equity, diversity, and inclusion in the Society for Vascular Surgery: A report of the Society for Vascular Surgery Task Force on Equity, Diversity, and Inclusion.

Diversity, equity, and inclusion represent interconnected goals meant to ensure that all individuals, regardless of their innate identity characteristics, feel welcomed and valued among their peers. Equity is achieved when all individuals have equal access to leadership and career advancement opportunities as well as fair compensation for their work. It is well-known that the unique backgrounds and perspectives contributed by a diverse workforce strengthen and improve medical organizations overall. The Society for Vascular Surgery (SVS) is committed to supporting the highest quality leadership, patient care, surgical education, and societal recommendations through promoting diversity, equity, and inclusion within the SVS. The overarching goal of this document is to provide specific context and guidance for enhancing diversity, equity, and inclusion within the SVS as well as setting the tone for conduct and processes beyond the SVS, within other national and regional vascular surgery organizations and practice settings.

Urgent need for individual mobile phone and institutional reporting of at home, hospitalized, and intensive care unit cases of SARS-CoV-2 (COVID-19) infection.

Approximately 90 days of the SARS-CoV-2 (COVID-19) spreading originally from Wuhan, China, and across the globe has led to a widespread chain of events with imminent threats to the fragile relationship between community health and economic health. Despite near hourly reporting on this crisis, there has been no regular, updated, or accurate reporting of hospitalizations for COVID-19. It is known that many test-positive individuals may not develop symptoms or have a mild self-limited viral syndrome consisting of fever, malaise, dry cough, and constitutional symptoms. However some individuals develop a more fulminant syndrome including viral pneumonia, respiratory failure requiring oxygen, acute respiratory distress syndrome requiring mechanical ventilation, and in substantial fractions leading to death attributable to COVID-19. The pandemic is evolving in a clustered, non-inform fashion resulting in many hospitals with preparedness but few or no cases, and others that are completely overwhelmed. Thus, a considerable risk of spread when personal protection equipment becomes exhausted and a large fraction of mortality in those not offered mechanical ventilation are both attributable to a crisis due to maldistribution of resources. The pandemic is amenable to self-reporting through a mobile phone application that could obtain critical information on suspected cases and report on the results of self testing and actions taken. The only method to understand the clustering and the immediate hospital resource needs is mandatory, uniform, daily reporting of hospital censuses of COVID-19 cases admitted to hospital wards and intensive care units. Current reports of hospitalizations are delayed, uncertain, and wholly inadequate. This paper urges all the relevant stakeholders to take up self-reporting and reporting of hospitalizations of COVID-19 as an urgent task in combating this devastating pandemic.

Vascular fellow and resident experience performing infrapopliteal revascularization with endovascular procedures and vein bypass during training.

OBJECTIVE: Endovascular aneurysm repair has led to a significant reduction in vascular trainee experience in the surgical treatment of aortic aneurysms. We sought to evaluate whether the vascular training paradigm or the "endovascular first" approach to lower extremity vascular disease has had a similar effect on trainee experience with infrapopliteal endovascular therapy and vein bypass. METHODS: Deidentified data were provided by the Vascular Surgery Board on the number of procedures performed by each 2014 fellowship and residency (0 + 5) graduate during training. Data were analyzed using parametric and nonparametric methods, where appropriate. RESULTS: Of 125 trainees (109 fellows, 16 residents), 33 (27%) performed 10 or fewer infrapopliteal vein bypasses and 37 (29%) performed 10 or fewer infrapopliteal endovascular procedures during their training. Eleven trainees (9%) performed 10 or fewer of both procedures. There was a positive correlation between number of infrapopliteal vein bypass and endovascular procedures performed (r = 0.19; P = .03). There was no difference between fellows and residents in the mean number of bypass operations performed during training (17.3 vs 19.1; P = .50; range, 0-53). However, residents performed more infrapopliteal endovascular procedures than fellows did (median, 29 vs 16; P = .03; range, 0-128). CONCLUSIONS: More than one in four graduates of both training paradigms finish with a low number of infrapopliteal bypasses and endovascular interventions. The number of these procedures needed for proficiency is not known. Vascular surgery training programs should critically evaluate the number of infrapopliteal procedures required to achieve proficiency.

Con: Contrast-induced nephropathy-should we try to avoid contrast media in patients with chronic kidney disease?

The incidence of acute kidney injury (AKI) attributed to iodinated contrast has been over-estimated and this has led clinicians to withhold potentially life-saving diagnostic and therapeutic interventions. There is mounting evidence that iodinated contrast plays only a minor role in the development of AKI in comparison with more significant risk factors such as pre-existing renal dysfunction, hemodynamic instability and exposure to nephrotoxic drugs. We will present data which challenge the dogma of avoiding iodinated contrast in patients with reduced renal function. Based on a rational and individualized risk-benefit analysis, we believe it is preferable to utilize iodinated contrast if alternate diagnostic or therapeutic options are comparatively ineffective or hazardous.

Case Report: An Innovative Endovascular Technique for Repair of Descending Thoracic Aortic Aneurysm following an Open Coarctation Repair.

It was once postulated that open surgical repair of coarctation of the aorta during childhood patients was cured. However, long-term follow-up has been significant for late problems such as an aneurysm. The incidence of such aneurysm after open surgical coarctation repair is 11-24%. If such an aneurysm is left untreated, patients are at a high risk of morbidity and mortality. Prior to the endovascular era, patients would require a redo open repair which in itself is a highly morbid operation. Currently, thoracic endovascular aortic repair (TEVAR) has been reported as a feasible and safe alternative to open surgical reprocedures in this context. However, TEVAR might be challenging due to the proximity of the pathology to supraaortic vessels and the ongoing presence of the coarctation. We are reporting a unique case of a 48-year-old male undergoing TEVAR due to aortic aneurysm after previous surgical coarctation treatment and successful closure of the coarctation with a vascular plug device.

Case Report: A Durable Open Repair of a Rare Profunda Aneurysm.

Profunda femoris artery aneurysms (PFAAs) are rare and difficult to diagnose in the early stages of development due to location and encasement in the deep thigh musculature. We report the case of a 74-year-old male who was discovered to have a right PFAA during evaluation for progressively worsening short distance claudication. He had undergone an angioplasty of the left iliofemoral system several months ago with no improvement of his symptoms. The PFAA was diagnosed through computed tomography angiography and repaired via syndactylization of profunda femoris branches and interposition grafting with a polytetrafluoroethylene stretch graft. The imaging features are described in the article. Although PFAAs are rare clinical presentations, their development should be considered, in particular when symptoms such as progressive or unchanging claudication are present in a patient following an angioplasty of the affected iliofemoral system.

Nonoperative management of grade III blunt thoracic aortic injuries.

OBJECTIVE: Blunt thoracic aortic injuries (BTAIs) have historically been treated with open surgery; thoracic endovascular aortic repair (TEVAR), however, is rapidly becoming the standard of care for all grades of injury. Previous studies have shown successful, conservative management of low-grade (I and II) BTAI, but limited literature exists regarding nonoperative management (NOM) for high-grade BTAI. The purpose of this study was to evaluate NOM for grade III BTAI compared with TEVAR. METHODS: There were 75 patients diagnosed with BTAI between January 2004 and June 2015. Of these, 40 were excluded for different grades of BTAI (17), death before any treatment (6), and need for urgent open repair (17). The remaining 35 patients were divided into two groups by treatment approach: NOM (n = 18) and TEVAR (n = 17). Primary end points were complications and mortality. The secondary end point was difference in pseudoaneurysm and aortic diameter measurements between groups. RESULTS: The groups of patients were similar in age, gender, Injury Severity Score, length of stay, in-hospital mortality, and hospital-associated complications. There were four TEVAR-related complications: graft involutions (2), type I endoleak (1), and distal embolization (1). All TEVAR-related complications required either an adjunctive procedure at the time of the primary procedure or an additional procedure. No patients from the NOM group required operative intervention. There were seven in-hospital mortalities: two in the TEVAR group (11.8%) and five in the NOM group (27.8%; P = .402). One death in the NOM group was related to aortic disease. Follow-up computed tomography imaging revealed similar aortic-related outcomes between groups, with a high proportion showing resolved or improved aortic injury (NOM, 87.5%; TEVAR, 92.9%; P = .674). Initial computed tomography imaging showed similar aortic diameters between groups. The average diameter of the aorta distal to the subclavian artery was 22.6 mm in the NOM group vs 22.8 mm in the TEVAR group (P = .85). The average maximum diameter of the pseudoaneurysm was 30.1 mm in the TEVAR group and 29.9 mm in the NOM group (P = .90). The average ratio of diameter of the pseudoaneurysm to diameter of the aorta distal to the subclavian artery was 1.32 for the TEVAR group and 1.33 for the NOM group (P = .85). CONCLUSIONS: The natural history of grade III BTAIs is not well described. This study suggests that observation and NOM of grade III BTAI may be a reasonable therapeutic option in selected patients. It also speaks to the need for further delineation of the natural history of this injury. Serial imaging and long-term follow-up are necessary to monitor the progression of the pseudoaneurysm.

Interobserver variability in physician-modified endograft planning by comparison with a three-dimensional printed aortic model.

BACKGROUND: With the increasing application of fenestrated and physician-modified endografting for aneurysm repair, there is increasing concern about the accuracy of vessel position measurements based on computed tomography scans. Inaccuracies in measurements may result in a "window-shutter" or "eclipsing" phenomenon whereby the fenestration may not overlie the vessel ostium completely. We hypothesized that vessel position measurements from reconstructed imaging do not represent the true vessel position as obtained from a three-dimensional (3D) printed physical model of the visceral aortic segment. METHODS: Medical 3D modeling software was used to develop the 3D reconstructions, which were then exported to the 3D printing software. This allowed 3D models to be physically generated. The distances to the top and bottom and the angle of each of the celiac, superior mesenteric, right renal, and left renal arteries were recorded. These same measurements were obtained by each of the blinded reviewers in addition to the aortic diameter at the midpoint of each of these vessels. Measurements were compared with intraclass correlation coefficient, nonparametric Spearman rank correlation test, and one-sample t-test to assess accuracy and precision. Statistical significance was set at P < .05 for all tests. RESULTS: Both the individual measurements and the average of the measurements were statistically accurate (significant) for the bottom of the superior mesenteric artery and the top and bottom of both the right and left renal arteries. There was variability and inaccuracy in all visceral vessel angles and in the bottom of the celiac artery (the top and the angle of the celiac artery were the arbitrary referents). CONCLUSIONS: Whereas the visceral vessel orifices are largely accurately assessed and measured, the vessel angles are not. This may lead to an eclipsing phenomenon, which may contribute to branch or fenestrated vessel failure and therefore reintervention. Further efforts should assess the clinical significance of the eclipsing phenomenon and should target accurate and appropriate fenestration construction to prevent long-term morbidity.

Outcomes after retroflexed gracilis muscle flap for vascular infections in the groin.

OBJECTIVE: Multiple catheterizations and procedures on the femoral arteries can increase the risk of infection and eventual destruction of the overlying skin and subcutaneous tissue. Without adequate tissue coverage, vascular structures are exposed and, thus, vulnerable to disruption. This can lead to loss of limb and/or life and carries a significant mortality. We hypothesized that gracilis muscle flap (GMF) was a reliable adjunct in providing healthy tissue coverage for a complex surgical problem. METHODS: Retrospective review of charts was performed on all patients who had undergone GMF for groin infections at a tertiary care medical center. RESULTS: From 1997 to 2012, GMF was performed in 68 limbs (64 patients) by vascular surgeons for infectious etiology to cover the common femoral artery. At the time the GMF was placed, the femoral artery had synthetic graft/patch in 14 limbs, whereas 54 limbs had procedures with autologous conduit. Complete healing was achieved in 58 (85%) limbs. Treatment was deemed not successful in 10 limbs where patients continued to have persistent infection. Six out of 10 limbs had anastomosis disruption requiring emergent ligation of the common femoral artery. Nine patients died during the perioperative period (30-day). There were a total of 13 amputations in 12 patients. Limb salvage was achieved in 55 limbs (81%). Univariate analysis suggested that patients that had revascularization procedures with synthetic graft had a higher complication rate compared with autologous/vein reconstruction (24% vs 5%; P = .021). This group also has a higher rate of persistent infection compared with the autologous group (24% vs 2%; P = .006). Patients older than 75 years at the time of GMF had a higher incidence of GMF-related complications (57% vs 5%; P = .04). Multivariate analysis confirmed that presence of prosthesis led to higher incidence treatment failures and muscle flap complications at the surgical site (odds ratio, 6.6; P = .04; and odds ratio, 13.3; P = .03, respectively). CONCLUSIONS: GMF is technically simple to perform and provides durable soft tissue coverage with a high rate of healing for complex groin wounds even in the presence of synthetic conduit.

An unusual cause of spinal cord ischemia after thoracic endovascular repair.

A 59-year-old left-handed man presented with chest pain and hypertension and was found to have an acute descending aortic dissection on imaging. After thoracic endovascular repair of the dissection, he developed left arm weakness and ischemia. Despite carotid-subclavian transposition, the patient was found to have persistent left triceps weakness as well as bilateral leg paresis. An urgent spinal drain was placed that improved his lower extremity deficit but did not greatly change his arm symptoms. Magnetic resonance imaging of the spine revealed previously undiagnosed severe multilevel spinal stenosis requiring operative decompression. To our knowledge, this is the first report of the contribution of cervical spinal stenosis to post-thoracic endovascular repair spinal ischemia.

A rare combination of atypical cerebral vascular anatomy.

A 57-year-old woman presented with neurologic deficits consistent with a cerebrovascular accident. Her workup demonstrated the simultaneous occurrence of three uncommon cerebrovascular congenital anomalies in a single patient: (1) persistent trigeminal artery, (2) persistent fetal origin of the posterior cerebral artery and (3) bilateral occurrence of the vertebral arteries terminating in the posterior inferior cerebellar arteries. These persistent fetal cerebrovascular anatomic variants are reviewed and the clinical relevance discussed.

Predicted shortfall in open aneurysm experience for vascular surgery trainees.

OBJECTIVE: Since the introduction of endovascular aneurysm repair (EVAR), the volume of open aneurysm repair (OAR) has steadily declined since 2000. The introduction of next-generation devices and branched and fenestrated endograft technology continues to increase the anatomic applicability of EVAR, further decreasing the need for OAR. This study models the decline in OAR and uses historical trends to forecast future decline in volume and its potential effect on vascular surgery training. METHODS: An S-curve modified logistic function was used to model the effect of introducing a new technology (EVAR) on the standard management of abdominal aortic aneurysm (AAA) with OAR starting in the year 2000, when an International Classification of Diseases, Ninth Revision, code was first introduced for EVAR. Patients who underwent EVAR and OAR for AAA were determined using the Nationwide Inpatient Sample from 1998 to 2011. Weighted samples and data from the United States Census Bureau were used to extrapolate these numbers to estimate population statistics. The number of cases completed at teaching hospitals was calculated using the Nationwide Inpatient Sample, and Accreditation Council for Graduate Medical Education case logs were used to forecast the number of cases completed by vascular surgery trainees. RESULTS: The highest number of OAR cases in this study was 42,872 in 2000 compared with just 10,039 in 2011. This was mirrored by a rise in EVAR from 2358 cases in 2000 (5.2%) to 35,028 in 2011 (76.5% by volume). Of the OAR volume in 2011, 6055 cases (60.3%) were completed at teaching institutions. An S-curve model with a correlation coefficient of R2 = 0.982 predicted 3809 open AAA cases at teaching hospitals by 2015, 2162 by 2020, and 1231 by 2025. When compared with the 2011 Accreditation Council for Graduate Medical Education National Resident Report, vascular surgery residents had 44.4% utilization with regard to OAR (2690 cases covered of 6055 total). When combined with the increase in vascular surgery trainees and lower number of open repairs, vascular fellows will complete about 10 OAR cases in 2015 and five OAR cases in 2020. CONCLUSIONS: The decreasing number of OAR cases will limit exposure for vascular trainees, who may be ill equipped to treat patients who require open repair beyond 2015. Additional methods for providing OAR training should be explored.

A systematic review of assessment of skill acquisition and operative competency in vascular surgical training.

OBJECTIVE: The aim of this systematic review is to describe the literature and assessment tools evaluating vascular surgical operative performance that could potentially be used for the assessment of educational outcomes applicable to the Milestone Project and the Next Accreditation System. METHODS: A systematic review of PubMed/MEDLINE, EMBASE, PsycINFO, and key journals from 1985 to 2013 was performed to identify English-language articles describing assessment of vascular surgical skills and competence. Qualifying studies were abstracted for data concerning study aims, study and assessment setting, skills measured, and metrics used to determine competency. Strengths, weaknesses, and psychometric robustness of the assessment tools were determined. RESULTS: The literature search identified 617 citations. After title and abstract review, 65 articles were retrieved for full-text assessment and 48 articles were included in the final review. Twenty-nine articles assessed open vascular skills; 19, endovascular skills; six, nontechnical skills; and one, teamwork skills. The majority (84%) of studies were performed in a simulated environment, four (8%) were performed in the operating room, and the remaining three were performed in both a simulated environment and an operating room. Strengths and weaknesses of assessment tools were study and assessor dependent, with none applicable to all study scenarios or procedures. CONCLUSIONS: The literature describing assessment tools pertinent to vascular surgery is diverse. Existing assessment tools may be relevant to individual technical skill acquisition assessment; however, an operative assessment tool relevant to vascular/endovascular surgery and generalizable to the wide spectrum of technical and nontechnical skills pertinent to vascular surgery needs to be developed, validated, and implemented to allow the practical assessment of resident readiness to operate in an unsupervised setting.

An early validation of the Society for Vascular Surgery lower extremity threatened limb classification system.

OBJECTIVE: The Society for Vascular Surgery (SVS) recently established the Lower Extremity Threatened Limb Classification System, a staging system using Wound characteristic, Ischemia, and foot Infection (WIfI) to stratify the risk for limb amputation at 1 year. Although intuitive in nature, this new system has not been validated. The purpose of the following study was to determine whether the WIfI system is predictive of limb amputation and wound healing. METHODS: Between 2007 and 2010, we prospectively obtained data related to wound characteristics, extent of infection, and degree of postrevascularization ischemia in 139 patients with foot wounds who presented for lower extremity revascularization (158 revascularization procedures). After adapting those data to the WIfI classifications, we analyzed the influence of wound characteristics, extent of infection, and degree of ischemia on time to wound healing; empirical Kaplan-Meier survival curves were compared with theoretical outcomes predicted by WIfI expert consensus opinion. RESULTS: Of the 158 foot wounds, 125 (79%) healed. The median time to wound healing was 2.7 months (range, 1-18 months). Factors associated with wound healing included presence of diabetes mellitus (P = .013), wound location (P = .049), wound size (P = .007), wound depth (P = .004), and degree of ischemia (P < .001). The WIfI clinical stage was predictive of 1-year limb amputation (stage 1, 3%; stage 2, 10%; stage 3, 23%; stage 4, 40%) and wound nonhealing (stage 1, 8%; stage 2, 10%; stage 3, 23%; stage 4, 40%) and correlated with the theoretical outcome estimated by the SVS expert panel. CONCLUSIONS: The theoretical framework for risk stratification among patients with critical limb ischemia provided by the SVS expert panel appears valid. Further validation of the WIfI classification system with multicenter data is justified.

A toolkit for individualizing interventions to mitigate second-victim syndrome in a diverse surgery community.

Adverse outcomes are an inevitable consequence of surgical care. The term "second victim" was introduced by Wu to describe the emotional trauma experienced by a clinician who feels responsibility for an adverse clinical outcome. Second victims may feel shame, guilt, sadness, and a crisis of confidence. Surgeons rarely seek professional support following an adverse event but are more likely to confide in colleagues. Surgeons who represent groups traditionally underrepresented in medicine may be less likely to seek assistance following an adverse clinical outcome. There is a need for surgeons to have sufficient training to provide peer-to-peer support for wounded colleagues. The PEARLS Toolkit provides a blueprint toward this end.

Assessment of Open Surgery Suturing Skill: Image-based Metrics Using Computer Vision.

OBJECTIVE: This paper presents a computer vision algorithm for extraction of image-based metrics for suturing skill assessment and the corresponding results from an experimental study of resident and attending surgeons. DESIGN: A suturing simulator that adapts the radial suturing task from the Fundamentals of Vascular Surgery (FVS) skills assessment is used to collect data. The simulator includes a camera positioned under the suturing membrane, which records needle and thread movement during the suturing task. A computer vision algorithm processes the video data and extracts objective metrics inspired by expert surgeons' recommended best practice, to "follow the curvature of the needle." PARTICIPANTS AND RESULTS: Experimental data from a study involving subjects with various levels of suturing expertise (attending surgeons and surgery residents) are presented. Analysis shows that attendings and residents had statistically different performance on 6 of 9 image-based metrics, including the four new metrics introduced in this paper: Needle Tip Path Length, Needle Swept Area, Needle Tip Area and Needle Sway Length. CONCLUSION AND SIGNIFICANCE: These image-based process metrics may be represented graphically in a manner conducive to training. The results demonstrate the potential of image-based metrics for assessment and training of suturing skill in open surgery.