Faculty Bibliography

Background and Objective: The use of robot technology has greatly expanded the field of general surgery. While robot technology has become almost standard for many general surgeons, there is an increasing interest in how this same technology may be utilized within more specialized fields. We sought to explore the advances and current uses of robot technology within the field of vascular surgery. We evaluated this topic broadly in the context of both the open and endovascular approach. Methods: A comprehensive literature search was employed using the following search strategy on PubMed: ("Robotic Surgical Procedures"[Mesh]) AND ("Vascular Surgical Procedures"[Mesh]). A total of 381 articles were identified. No filters were applied. All articles were then screened manually for applicability. Articles relating to cardiothoracic and neurosurgery were excluded (n=366), as the authors were most interested in performing this literature review from the focus of the vascular surgeon, and procedures involving the heart and brain are outside his or her scope of practice. The remaining (n=15) articles were then utilized to provide a synopsis of the advances made in robotic-assisted procedures within the field of vascular surgery. Key Content and Findings: Robot technology is currently being utilized by vascular surgeons to assist in both open and endovascular procedures. Some typical open procedures wherein the robot has shown to be most effective are in complex aortic reconstruction, first rib resection, venous thrombectomy and venous reconstruction following oncologic resection. In addition to open procedures, there is also evidence that robot technology may offer some benefits in purely endovascular ones, such as in inferior vena cava (IVC) filter retrieval and in standard angiograms. Conclusions: This work highlights that robot technology is greatly expanding the field of vascular surgery. In addition to offering a less invasive approach for both major and minor procedures, robot technology has also led to significant increases in team members"™ safety by decreasing radiation exposure. This review will hopefully act as a catalyst to further expand the use of robot technology in vascular procedures, and by effect increase the value that the vascular surgeon brings to the health care system.

STUDY DESIGN/METHODS:Delphi method. OBJECTIVE:To gain consensus on the following questions: (1) When should anticoagulation/antiplatelet (AC/AP) medication be stopped before elective spine surgery?; (2) When should AC/AP medication be restarted after elective spine surgery?; (3) When, how, and in whom should venous thromboembolism (VTE) chemoprophylaxis be started after elective spinal surgery? SUMMARY OF BACKGROUND DATA/BACKGROUND:VTE can lead to significant morbidity after adult spine surgery, yet postoperative VTE prophylaxis practices vary considerably. The management of preoperative AC/AP medication is similarly heterogeneous. MATERIALS AND METHODS/METHODS:Delphi method of consensus development consisting of three rounds (January 26, 2021, to June 21, 2021). RESULTS:Twenty-one spine surgeons were invited, and 20 surgeons completed all rounds of questioning. Consensus (>70% agreement) was achieved in 26/27 items. Group consensus stated that preoperative Direct Oral Anticoagulants should be stopped two days before surgery, warfarin stopped five days before surgery, and all remaining AC/AP medication and aspirin should be stopped seven days before surgery. For restarting AC/AP medication postoperatively, consensus was achieved for low-risk/medium-risk/high-risk patients in 5/5 risk factors (VTE history/cardiac/ambulation status/anterior approach/operation). The low/medium/high thresholds were POD7/POD5/POD2, respectively. For VTE chemoprophylaxis, consensus was achieved for low-risk/medium-risk/high-risk patients in 12/13 risk factors (age/BMI/VTE history/cardiac/cancer/hormone therapy/operation/anterior approach/staged separate days/staged same days/operative time/transfusion). The one area that did not gain consensus was same-day staged surgery. The low-threshold/medium-threshold/high-threshold ranges were postoperative day 5 (POD5) or none/POD3-4/POD1-2, respectively. Additional VTE chemoprophylaxis considerations that gained consensus were POD1 defined as the morning after surgery regardless of operating finishing time, enoxaparin as the medication of choice, and standardized, rather than weight-based, dose given once per day. CONCLUSIONS:In the first known Delphi study to address anticoagulation/antiplatelet recommendations for elective spine surgery (preoperatively and postoperatively); our Delphi consensus recommendations from 20 spine surgeons achieved consensus on 26/27 items. These results will potentially help standardize the management of preoperative AC/AP medication and VTE chemoprophylaxis after adult elective spine surgery.

INTRODUCTION/BACKGROUND:The proportion of open aneurysm repairs requiring at least a suprarenal clamp has increased in the past few decades, partly due to preferred endovascular approaches for most patients with infrarenal aneurysms, suggesting that the management of aortic clamp placement has become even more relevant. This study evaluated the association between proximal clamp site and intraoperative ischemia times with postoperative renal dysfunction and mortality. METHODS:We used the Vascular Quality Initiative to identify all patients undergoing open repairs of elective or symptomatic juxtarenal AAAs from 2004-2018 and compared outcomes by clamp site: above one renal artery, above both renal arteries (supra-renal), or above the celiac trunk (supra-celiac). Outcomes evaluated included acute kidney injury (AKI), new-onset renal failure requiring renal replacement therapy (RRT), 30-day mortality, and one-year mortality. We used multilevel logistic regressions and cox-proportional hazards models, clustered at the hospital level, to adjust for confounding. RESULTS:We identified 3976 patients (median age 71 years, 70% male, 8.2% non-Caucasian), with a median aneurysm diameter of 5.9cm (IQR 5.4-6.8cm). Proximal clamp sites were: above one renal artery (31%), supra-renal (52%), and supra-celiac (17%). Rates of unadjusted outcomes were 20.5% for AKI, 4.1% for new-onset RRT, 4.9% for 30-day mortality, and 8.3% for one-year mortality. On adjusted analyses, independent of ischemia time, supra-renal clamping relative to clamping above a single renal artery had higher odds of postoperative AKI (aOR 1.50 [95%-CI 1.28-1.75]) but similar odds for new-onset RRT (aOR 1.27 [0.79-2.06]) and 30-day mortality (aOR 1.12 [0.79-1.58]) and hazards for one-year mortality (aHR 1.12 [0.86-1.45]). However, every ten minutes of prolonged intraoperative ischemia time was associated with an increase in odds or hazards ratio of postoperative AKI by +7% (IQR 3-11%), new-onset RRT by +11% (IQR 4-17%), 30-day mortality by +11% (IQR 6-17%), and one-year mortality by +7% (IQR 2-13%). Patients with greater than 40 minutes of ischemia time had notably higher rates of all four outcomes. DISCUSSION/CONCLUSIONS:Supra-renal clamping relative to clamping above a single renal artery was associated with AKI but not new-onset RRT or 30-day mortality. However, intraoperative renal ischemia time was independently associated with all four postoperative outcomes. While further studies are warranted, our findings suggest that an expeditious proximal anastomosis creation is more important than trying to maintain clamp position below one renal artery, suggesting that suprarenal clamping may be the best strategy for open AAA repair when needed to efficiently perform the proximal anastomosis.

OBJECTIVE:Transfemoral carotid artery stenting (TFCAS) has higher combined stroke and death rates in elderly patients with carotid artery stenosis compared with carotid endarterectomy (CEA). However, transcarotid artery revascularization (TCAR) may have similar outcomes to CEA. This study compared outcomes after TCARs relative to those after CEAs and TFCAS, focusing on elderly patients. METHODS:We included all patients with carotid artery stenosis, and no prior endarterectomy or stenting, who underwent either a CEA, TFCAS, or TCAR in the Vascular Quality Initiative from September 2016 (TCAR commercially available) to December 2019. We categorized patients into age decades: 60-69 years, 70-79 years, and 80-90 years. Outcomes included 30-day and one-year composite rates of stroke or death. Cox-proportional hazards models evaluated both outcomes after adjusting for patient demographics, clinical factors, symptomatology, hospital CEA volume, and clustering. RESULTS:We identified 33,115 patients who underwent either a CEA, TFCAS, or TCAR for carotid artery stenosis (35% in their 60s, 44% in their 70s, and 21% in their 80s), where half (50%) were symptomatic. The majority of patients had CEAs (80%), followed by TFCAS (11%) and then TCARs (9.1%). The overall rate of 30-day stroke/death was 1.5% and of one-year stroke/death was 4.4%. Octogenarians had the highest 30-day and one-year stroke/death rates relative to their peers (2.3% and 6.3%, respectively). Among all patients, the adjusted hazards of TCARs relative to CEAs was similar for 30-day stroke/death (HR 1.10 [95%-CI 0.75-1.62]) and slightly higher for one-year stroke/death (HR 1.34 [1.02-1.76]). Among octogenarians, however, the adjusted hazards of TCARs relative to CEAs was similar for both 30-day stroke/death (HR 1.12 [0.59-2.13]) and one-year stroke/death (HR 1.28 [0.85-1.94]). TFCAS relative to CEAs had higher hazards of both 30-day stroke/death (HR 1.78 [1.10-2.89]) and one-year stroke/death (HR 1.85 [1.35-2.54]) in octogenarians. CONCLUSIONS:TCARs had similar outcomes relative to CEAs among octogenarians with respect to 30-day and one-year rates of stroke/death. TCAR may serve as a promising less-invasive treatment for carotid disease in older patients who are deemed high anatomic, surgical, or clinical risk for CEAs.

OBJECTIVE:Previous studies evaluating the association between abdominal aortic aneurysm (AAA) size with postoperative outcomes after open repairs seldom accounted for renal or visceral artery involvement, proximal clamp site, intraoperative renal ischemia time, and hospital volume. This study examined the association between aneurysm size with outcomes after open repairs. METHODS:We identified patients who underwent open repairs of infrarenal versus juxtarenal nonruptured AAAs, defined by proximal clamp site, in the 2004-2019 Vascular Quality Initiative. Outcomes included 30-day mortality, postoperative complications, failure to rescue, and 1-year mortality. Multivariable logistic regressions adjusted for patient characteristics, operative factors, hospital volume, and hospital clustering. RESULTS:We identified 8011 patients (54% infrarenal, 46% juxtarenal). The median aneurysm size did not differ between infrarenal versus juxtarenal aneurysms (5.7 cm vs 5.9 cm; P = .12). For infrarenal aneurysms, every 1-cm increase in size increase the adjusted odds ratio (OR) or hazard ratio (HR) of 30-day mortality by 18% (OR, 1.18; 95% CI, 1.06-1.31), failure to rescue by 20% (OR, 1.20; 95% CI, 1.06-1.34), 1-year mortality by 18% (HR, 1.18; 95% CI, 1.10-1.26), but not complications (OR, 1.03; 95% CI, 0.98-1.07). For juxtarenal aneurysm, larger aneurysm sizes were not associated with any outcome. Proximal clamp site, ischemia time, and volume were associated with outcomes. CONCLUSIONS:The association between AAA size and outcomes matters less with renal and visceral artery aneurysmal involvement, having important implications for surgical decision-making, operative planning, and patient counseling.

Degenerative lumbar pathologies are commonly encountered at the lumbosacral junction. The transition from the mobile lumbar spine to the stiff sacroiliac segment results in high biomechanical stresses and can lead to disc degeneration, ligamentum flavum hypertrophy, neural foraminal stenosis, and other causes of pain or neurologic deficit. Surgical intervention at the lumbosacral junction must be tailored to maximize pain relief and relieve neural compression and reverse neurologic deficit while preserving the spine's natural biomechanical strength and flexibility and preventing the slow march of adjacent segment degeneration cranially into the thoracolumbar spine. It is our practice to offer combined anterior and posterior minimally invasive options when appropriate to maximize neural decompression and pain relief while ensuring proper segmental alignment and maximizing fusion rates through a minimally disruptive approach. In this article we detail a common presentation of lumbosacral pathology and the approach and considerations for a single position, minimally invasive anterior and posterior approach at the L5/S1 segment.

BACKGROUND:In this report, we present our experience with nonresective repair of abdominal aortic aneurysm in selected patients who were unsuited for other surgical approaches and would benefit from repair. METHODS:Seven patients with abdominal aortic aneurysm underwent nonresective repair comprising aneurysm embolization followed by the creation of an axillary-femoral, femoral-femoral bypass with a polytetrafluoroethylene (PTFE) graft. RESULTS:Between April 2006 and March 2009, seven patients (mean age: 85 years) underwent surgery. Of these, four (57%) are currently alive and healthy, with a mean follow-up of 15.7 months, the remaining three died. CONCLUSION/CONCLUSIONS:Nonresection may be used as an alternative surgical treatment in certain high-risk patients.

OBJECTIVE: The standard technique of balloon angioplasty with or without subintimal dissection of infrainguinal arteries requires contrast arteriography and fluoroscopy. We attempted to perform this procedure with duplex guidance to avoid the use of nephrotoxic contrast material and eliminate or minimize radiation exposure. METHODS: From September 2003 to June 2005, 196 patients (57% male) with a mean age of 73 +/- 10 years (range, 42-97 years) had a total of 253 attempted balloon angioplasties of the superficial femoral and/or popliteal artery under duplex guidance in 218 limbs. Critical ischemia was the indication in 38% of cases, and disabling claudication was the indication in 62%. Hypertension, diabetes, chronic renal insufficiency, smoking, and coronary artery disease were present in 78%, 51%, 41%, 39%, and 37% of patients, respectively. The TransAtlantic Inter-Society Consensus (TASC) classification was used for morphologic description of femoral-popliteal lesions. The common femoral artery was cannulated under direct duplex visualization. Still under duplex guidance, a guidewire was directed into the proximal superficial femoral artery, across the diseased segment(s), and parked at the tibioperoneal trunk. The diseased segment(s) were then balloon-dilated. Balloon diameter and length were chosen according to arterial measurements obtained by duplex scan. Hemodynamically significant defects causing diameter reductions greater than 30% and peak systolic velocity ratios greater than 2 were stented with a variety of self-expandable stents under duplex guidance. Completion duplex examinations and ankle-brachial indices were obtained routinely before hospital discharge. RESULTS: There were 11 (4%) TASC class A lesions, 31 (12%) TASC class B lesions, 177 (70%) TASC class C lesions, and 34 (14%) TASC class D lesions in this series. The overall technical success was 93% (236/253 cases). Eight of the 17 failed subintimal dissections belonged to TASC class C and the remaining 9 to TASC class D. End-stage renal disease was the only significant predictor of subintimal dissection failure in patients with femoral-popliteal occlusions (5/17 cases; P < .04). Intraluminal stents were placed in 153 (65%) of 236 successful cases. Overall pre-procedure and post-procedure ankle-brachial indices changed from a mean of 0.69 +/- 0.16 (range, 0.2-1.1) to 0.95 +/- 0.14 (range, 0.55-1.3), respectively (P < .0001). The mean duration of follow-up was 10 +/- 7 months (range, 1-29 months). The overall 30-day survival rate was 100%. Overall limb salvage rates were 94% and 90% at 6 and 12 months, respectively. Six-month patency rates for TASC class A, B, C, and D lesions were 89%, 73%, 72%, and 63%, respectively. Twelve-month patency rates for TASC class A, B, C, and D lesions were 89%, 58%, 51%, and 45%, respectively. CONCLUSIONS: Duplex-guided balloon angioplasty and stent placement seems to be a safe and effective technique for the treatment of infrainguinal arterial occlusive disease. Technical advantages include direct visualization of the puncture site, accurate selection of the proper size balloon and stent, and confirmation of the adequacy of the technique by hemodynamic and imaging parameters. Additional benefits are avoidance of radiation exposure and contrast material.

We have noted a significant incidence of pulmonary embolism (PE) and mortality associated with upper extremity deep venous thrombosis (UEDVT). Since there is an association between site of lower extremity DVT (LEDVT) and PE, we hypothesized that there might also be a correlation between site of UEDVT and PE with associated mortality. To further elucidate this hypotheses, we analyzed the mortality and incidence of PE diagnosed with subclavian/axillary/internal jugular vein thrombosis during an 11-year period at our institution and compared the data to those of patients diagnosed with brachial DVT. We studied 598 patients diagnosed with acute internal jugular, subclavian, axillary, or brachial DVT by duplex scanning. The patients were divided into three groups based on the most proximal location of the thrombus: group I, UEDVT involving the subclavian or axillary veins (n = 467); group II, isolated internal jugular DVT (n = 80); group III, brachial DVT alone (n = 52). Mortality rates at 2 months were 29%, 25%, and 21% for each group, respectively. The number of patients diagnosed with PE by ventilation/perfusion scans in groups I, II, and III, respectively, were 5%, 6.25% and 11.5% (p = 0.13). Furthermore, stratification by risk factors failed to demonstrate factors associated with increased 2-month mortality. Contrary to the initial hypothesis of a relationship between the site of thrombosis and the incidence of PE and mortality, these data demonstrated no statistical differences in mortality or incidence of PE among the groups studied. Additionally, these data suggest that brachial vein thrombosis is a disease process related to comparable associated mortality and morbidity similar to other forms of UEDVT. Based on these data, we suggest that UEDVT may be thought of as a marker for the severity of systemic illness of the patient rather than just as a cause of venous thromboembolism.

The clinical importance of upper extremity deep venous thrombosis (UEDVT) has been increasingly demonstrated in recent literature. Not only has the risk of pulmonary embolism from isolated upper extremity DVT been demonstrated, but a significant associated mortality has been encountered. Examination of this group of patients has demonstrated the existence of combined upper and lower extremity deep venous thrombosis (DVT) in some patients who exhibit an even higher associated mortality. As a result of this information, it has become the standard practice at this institution to search for lower extremity DVTs in patients found to have acute thrombosis of upper extremity veins. Since January 1999, there have been a total of 227 patients diagnosed with acute UEDVT. Within this group, 211 (93%) patients had lower extremity studies; 45 of these 211 (21%) had acute lower extremity DVTs by duplex examination in addition to the upper extremity DVTs. Overall, there were 145 women, 66 men, and the average age was 70 +/-1.2 (SEM); 22 of these patients had bilateral lower extremity thrombosis (LEDVT), and 8 patients were found to have chronic thrombosis of lower extremity veins. Of the patients with bilateral upper extremity DVTs, there were 3 with bilateral LE acute DVTs. Finally, 8 of the remaining 166 patients (5%) with originally negative lower extremity studies were found to develop a thrombosis at a later date. These data serve to confirm previous studies, on a larger scale, that there should be a high index of suspicion in patients with UEDVT of a coexistent LEDVT.