Proximal fixation of endovascular aortic device may not be associated with renal function decline after abdominal aortic aneurysm repair.

OBJECTIVE: Significant debate exists among providers who perform endovascular abdominal aortic aneurysm repair (EVAR) regarding the renal function change between suprarenal (SuF) and infrarenal (InF) fixation devices. The purpose of this study is to review our institution's experience using these devices in terms of renal function. METHODS: This is a retrospective review of all elective EVARs performed within a three-site health system (Florida, Minnesota, and Arizona) during the period of 2000 to 2018. The primary outcome was renal function decline on long-term follow-up depending on the anatomical fixation of the device (SuF vs InF). Secondary outcomes were length of hospitalization (LOH) and progression to hemodialysis. Multivariable regression analysis was performed to test for associations affecting LOH. RESULTS: There were 1130 elective EVARs included in our review. Of those, 670 (59.3%) had SuF and 460 (40.7%) InF. Long-term follow-up was 4.8 ± 3.7 years, and the rate of change in creatinine and estimated glomerular filtration rate (eGFR) were not statistically significant among groups (SuF vs InF). LOH was higher in those individuals with a SuF device (3.4 ± 2.2 vs 2.3 ± 1.0 days; P < .001). Ten patients with chronic kidney disease progressed to hemodialysis at 6.7 ± 3.8 years from EVAR. On Kaplan-Meier analysis, patients with chronic kidney disease with SuF were more likely to progress to hemodialysis (P = .039). On multivariable regression, female sex (Coef, 2.4; 95% confidence interval [CI], 0.17-0.41; P = .02), SuF (Coef, 9.5; 95% CI, 0.11-1.11; P < .0001), and intraoperative blood loss of greater than 150 mL (Coef, 15.4; 95% CI, 0.11-1.76; P < .0001) were predictors of prolonged LOH. CONCLUSIONS: Our three-site, single-institution data indicate that, although the starting eGFR was statistically lower in those individuals undergoing elective EVAR with InF, device fixation type did not affect the creatinine and eGFR on long-term follow-up. However, caution should be exercised at the time of abdominal aortic aneurysm repair in those individuals who already presented with renal dysfunction.

Dose reduction using digital fluoroscopy versus digital subtraction angiography in endovascular aneurysm repair: A prospective randomized trial.

OBJECTIVE: Endovascular aneurysm repair (EVAR) can result in high radiation dose to patients and operators. This prospective randomized study aimed to assess whether patient radiation dose sustained during EVAR could be decreased by predominantly using digital fluoroscopy (DF) vs the standard technique using digital subtraction angiography (DSA). METHODS: Between February 2011 and June 2017, patients with EVAR of infrarenal abdominal aortic aneurysms were prospectively enrolled and randomly assigned to a standard treatment DSA cohort or a DF cohort in which two or fewer DSA acquisitions were allowed for confirmatory imaging. Primary end points included dose-area product (DAP) and cumulative air kerma. Secondary end points included technical success and conversion to DSA standard treatment (if DF was inadequate for visualization). RESULTS: For all 43 patients enrolled (26 in the DF cohort, 17 in the DSA cohort), technical success was 100%. Of the 26 DF patients, 5 (19%) required conversion to the DSA cohort. In an intention-to-treat analysis, mean DAP was significantly lower in the DF cohort than in the DSA cohort (132 vs 174 Gy·cm2; P = .04). When patients were separated by number of DSA acquisitions (two or fewer vs three or more), mean DAP decreased 41% (109 vs 185 Gy·cm2; P = .005) and cumulative air kerma decreased 40% (578 vs 964 mGy; P = .004). CONCLUSIONS: In most patients (81%), DF or limited DSA was adequate for visualization during EVAR. In both intention-to-treat DF and limited-DSA cohorts, mean DAP was significantly decreased. If image quality allows, a DF-only or limited-DSA approach to EVAR decreases radiation dose.

Patient and institutional factors associated with postoperative opioid prescribing after common vascular procedures.

OBJECTIVE: Overprescription of postoperative opioid medication is a major contributor to the opioid abuse epidemic in the United States. Research into prescribing practices has suggested that patients be limited to 7 days or <200 morphine milligram equivalents (MME) after surgical procedures. Our aim was to identify patient or institutional factors associated with increased opioid prescriptions. METHODS: Opioid naive patients from an integrated health system undergoing one of nine surgical and endovascular procedures tracked within the Vascular Quality Initiative from 2015 to 2017 were identified and matched to their discharge and refill opioid prescriptions. Discharge opioid prescriptions were converted to MME. The primary outcome was discharge MME >200, and secondary outcomes were procedure-specific top-quartile opioid prescription and medication refills. Multivariable logistic regression was used to assess patient and perioperative factors associated with each outcome. RESULTS: Among 1546 opioid naive patients, 739 (48%) received a discharge opioid prescription; median MME was 0 (interquartile range, 0-150), and 349 (23%) had >200 MME. Among those with a discharge prescription, median MME was 180 (interquartile range, 150-300). MME varied by procedure (P < .001), with highest MME after suprainguinal bypass (median, 225) and infrainguinal bypass (200) and lowest MME after carotid artery stenting, carotid endarterectomy, and percutaneous peripheral vascular intervention (all medians of 0). On multivariable analysis, factors associated with MME >200 included younger patient age (<65 vs ≥ 80 years; odds ratio [OR], 3.0; 95% confidence interval [CI], 1.9-4.6; P < .001), treating institution B vs A (OR, 3.50; 95% CI, 2.42-5.07; P < .001) and C vs A (OR, 3.90; 95% CI, 2.66-5.74; P < .001), procedure-specific top-quartile length of stay (OR, 1.45; 95% CI, 1.01-2.08; P = .047), and prior tobacco use (OR, 1.60; 95% CI, 1.07-2.37; P = .02). The same variables along with current tobacco use and lack of preoperative aspirin were associated with procedure-specific top-quartile MME at discharge. Chronic beta-blocker use was protective of top-quartile MME. Based on the observed variability, an institutional standard for opioid prescribing has been developed for standardization. CONCLUSIONS: Opioid prescriptions at discharge vary with the invasiveness of vascular surgical procedures. Less than 25% of patients receive >200 MME. Variation by center represents a lack of standardization in prescribing practices and an opportunity for further improvement based on developed guidelines. Patient factors and procedure type can alert clinicians to patients at risk of higher than recommended MME.

Current surgical management of carotid body tumors.

BACKGROUND: Carotid body tumors (CBTs) are rare. Management guidelines may include genetic testing for succinate dehydrogenase (SDH) mutations. We performed an institutional review of the surgical management of CBT. METHODS: A retrospective analysis (1994-2015) of CBT excisions at our institution was performed. Data obtained included demographics, genetic testing (if performed), intraoperative details, postoperative morbidity, and long-term outcomes. Data from the first CBT excision were included in patients with bilateral tumors. Genetic testing was routinely offered in patients with a family history of CBT or multiple paragangliomas. RESULTS: A total of 183 CBTs (124 female [67.7%]) were excised. A neck mass was present in 106 patients (57.9%), 24 patients (12.1%) presented with tenderness or neck pain, and 3 (1.6%) presented with cranial nerve dysfunction. Computed tomography (57.9%) or magnetic resonance imaging (51.3%) were the most commonly used imaging modalities. Preoperative angiography was performed in 73 patients (39.8%), and 62 of them (84.5%) underwent embolization or internal carotid balloon occlusion testing, or both. Mean tumor diameter was 3.2 cm (range, 0.6-7.2 cm). There were 71 (38.8%), 75 (41%), and 37 (20.2%) Shamblin type 1, 2, and 3 tumors, respectively. Average operating time was 224 minutes (range, 52-696 minutes). Average blood loss was 143.9 mL (range, 10-2000 mL). Arterial reconstruction with an interposition graft was required in 10, and patch angioplasty was performed in four. Cranial nerve injury was permanent in 10 (5.5%), and the rate of stroke was 1% (n = 2). A total of 382 lymph nodes were excised, and all were benign. There were no deaths ≤30 days. Only one patient presented with malignant disease 2 years after CBT excision, and this patient did not undergo genetic testing. Thirty-four (18.6%) had a family history of CBT. SDH testing was performed in 18 patients, and 17 tested positive. Positive genetic testing had a correlation with earlier age at operation (P < .0001). Mean age at diagnosis of patients with SDH mutations was 38.0 years, and patients without known SDH mutations presented at a mean age of 50.3 years. In patients with SDH mutations, tumor diameter, operating time, blood loss, and distribution of Shamblin type 1, 2, and 3 lesions were not significantly different compared with the control group. CONCLUSIONS: CBT can be treated with minimal morbidity and mortality; however, the subgroup of patients with positive SDH mutations may represent a variant group of younger patients. Vascular surgeons should be aware of genetic testing to identify patients and family members who should undergo additional preoperative testing and monitoring for other paragangliomas. Concomitant lymph node dissection does not appear to add value in absence of clinic suspicion for malignancy.

Surgical and medical management of extracranial carotid artery aneurysms.

OBJECTIVE: Extracranial carotid artery aneurysms (ECCAs) are extremely rare with limited information about management options. Our purpose was to review our institution's experience with ECCAs during 15 years and to discuss the presentation and treatment of these aneurysms. METHODS: A retrospective review of patients diagnosed with ECCAs from 1998 to 2012 was performed. Symptoms, risk factors, etiology, diagnostic methods, treatments, and outcomes were reviewed. RESULTS: During the study period, 141 aneurysms were diagnosed in 132 patients (mean age, 61 years; 69 men). There were 116 (82%) pseudoaneurysms and 25 (18%) true aneurysms; 69 (49%) aneurysms were asymptomatic, whereas 72 (52%) had symptoms (28 painless masses; 10 transient ischemic attacks; 10 vision symptoms; 9 ruptures; 8 strokes; 4 painful mass; 1 dysphagia; 1 tongue weakness; 1 bruit). Causes of true aneurysms included fibromuscular dysplasia in 15 patients, Ehlers-Danlos syndrome in three, Marfan syndrome in one, and uncharacterized connective tissue diseases in two. Of 25 true aneurysms, 11 (44%) were symptomatic; 15 (60%) true aneurysms underwent open surgical treatment, whereas 10 (40%) were managed nonoperatively. Postoperative complications included one stroke during a mean follow-up of 31 months (range, 0-166 months). No aneurysms managed nonoperatively required intervention during a mean follow-up of 77 months (range, 1-115 months). Of 116 pseudoaneurysms, 60 (52%) were symptomatic; 33 (29%) pseudoaneurysms underwent open surgery, 18 (15%) underwent endovascular intervention, and 65 (56%) were managed medically. Pseudoaneurysm after endarterectomy (28 patients; 24%) presented at a mean of 82 months from the surgical procedure. Mean follow-up for all aneurysms was 33.9 months. One (0.7%) aneurysm-related death occurred (rupture treated palliatively). No patient undergoing nonoperative management suffered death or major morbidity related to the aneurysm. Nonoperative management was more common in asymptomatic patients (71%) than in symptomatic patients (31%). CONCLUSIONS: ECCAs are uncommon and may be manifested with varying symptoms. All segments of the carotid artery are susceptible, although the internal is most commonly affected. Open surgical intervention was more common in patients with symptoms and with true aneurysms. Patients with pseudoaneurysms were more likely to undergo endovascular intervention. Nonoperative treatment is safe in selected patients.

Distance bias and surgical outcomes.

BACKGROUND: A body of research has found that patients who travel a significant distance to obtain medical treatment experience better outcomes, a phenomenon termed "distance bias." This study uses risk-adjusted surgical outcomes data to analyze distance bias in a population of patients treated surgically at a tertiary care institution. METHODS: We used risk-adjusted surgical outcomes data from the National Surgical Quality Improvement Project at the Mayo Clinic to calculate observed and expected risk of a severe complication. Operations were stratified into quintiles based on the distance traveled by the patient. RESULTS: The average age of patients in our cohort was 56.7 years, and 59.2% were female; patients traveled an average of 226 miles for treatment. Patients living closest to the Mayo Clinic (quintile 1) had lower observed and expected risks of a severe complication relative to patients in quintiles 2-5. Patients from quintile 1 had outcomes which were better than predicted [observed:expected risk ratio of 0.82 (range, 0.63-0.99)]. Patients traveling intermediate distances (quintile 2) had outcomes which were worse than predicted [observed:expected risk ratio of 1.18 (range, 1.00-1.42)]. Operations performed on patients from greater distances (quintiles 3-5) had an observed risk of severe complications which was similar to expected. DISCUSSION: The phenomenon of distance bias which has previously been documented in medical and oncologic treatment is not demonstrated in this study. An opposite phenomenon may be more pertinent, where patients who are treated locally are less likely to have a severe complication and have outcomes which are better than predicted.

Elimination of pneumothorax and hemothorax during placement of implantable venous access ports using ultrasound and fluoroscopic guidance.

Implantable venous access ports are essential for patients requiring chronic venous access. Ultrasound guided catheter placement has been recognized as a valuable adjunct for reducing complications during placement of access ports in the radiology and critical care medicine literature. We reviewed the medical records of patients undergoing insertion of implantable venous access ports from June 2006 through June 2009. All procedures were performed using ultrasound guidance with the internal jugular vein as the access site. There were 500 implantable venous access ports placed and included for review. There were no post-procedure pneumothoraces or hemothoraces. Carotid puncture was documented in 4 (0.8%)cases. Routine use of ultrasound guidance during placement of implantable venous access ports has eliminated the complications of pneumothorax and hemothorax during placement of internal jugular venous access ports on our vascular surgery service. Elimination of these complications and decreased use of chest x-rays should also provide increased cost savings for this procedure.

Treatment of Ruptured Wide-Necked Aneurysms using a Microcatheter Injectable Biomaterial.

Ruptured wide-neck aneurysms (WNAs), especially in a setting of coagulopathy, are associated with significant morbidity and mortality. It is shown that by trapping a sub-millimeter clinical catheter inside the aneurysm sac using a flow diverter stent (FDS), instant hemostasis can be achieved by filling the aneurysm sac using a novel biomaterial, rescuing catastrophic bleeding in large-animal models. Multiple formulations of a biomaterial comprising gelatin, nanoclay (NC), and iohexol are developed, optimized, and extensively tested in vitro to select the lead candidate for further testing in vivo in murine, porcine, and canine models of WNAs, including in a subset with aneurysm rupture. The catheter-injectable and X-ray visible versions of the gel embolic agent (GEA) with the optimized mechanical properties outperform control groups, including a subset that receive a clinically used liquid embolic (Onyx, Medtronic), with and without aneurysm rupture. A combinatorial approach to ruptured WNAs with GEA and FDS may change the standard of medical practice and save lives.

Treatment of Ruptured and Nonruptured Aneurysms Using a Semisolid Iodinated Embolic Agent.

Saccular aneurysms (SAs) are focal outpouchings from the lateral wall of an artery. Depending on their morphology and location, minimally invasive treatment options include coil embolization, flow diverter stents, stent-assisted coiling, and liquid embolics. Many drawbacks are associated with these treatment options including recanalization, delayed healing, rebleeding, malpositioning of the embolic or stent, stent stenosis, and even rupture of the SA. To overcome these drawbacks, a nanoclay-based shear-thinning hydrogel (STH) is developed for the endovascular treatment of SAs. Extensive in vitro testing is performed to optimize STH performance, visualization, injectability, and endothelialization in cell culture. Femoral artery saccular aneurysm models in rats and in pigs are created to test stability, efficacy, immune response, endothelialization, and biocompatibility of STH in both ruptured and unruptured SA. Fluoroscopy and computed tomography imaging consistently confirmed SA occlusion without recanalization, migration, or nontarget embolization; STH is also shown to outperform coil embolization of porcine aneurysms. In pigs with catastrophic bleeding due to SA rupture, STH is able to achieve instant hemostasis rescuing the pigs in long-term survival experiments. STH is a promising semisolid iodinated embolic agent that can change the standard of medical practice and potentially save lives.

Surgical management of tumors invading the aorta and major arterial structures.

BACKGROUND: This study investigates surgical management of tumors arising from or involving the aorta and major arterial structures. METHODS: A retrospective single institutional review was conducted of patients undergoing arterial resection for tumors involving the aorta or major arterial structures between January 1992 and May 2009 at a tertiary care center. Patients with tumors abutting arteries without necessitating resection and those involving only venous structures were excluded. Patients were analyzed in groups by vessel involvement: aorta, carotid, external/common iliac, internal iliac, superficial femoral, and miscellaneous. RESULTS: Sixty patients were identified and included for review. The iliac arteries were most often resected, and sarcomatous pathology was most common (37 patients, 62%). Twelve patients underwent aortic resection, with eight (67%) of these undergoing graft reconstruction, one (8%) graft patch, and two (17%) primary repair. None of the 17 patients undergoing internal iliac resection underwent reconstruction, whereas the majority of patients in all other groups underwent reconstruction. Thirty-day mortality (TDM) was 0% in all groups, except the aortic (2/12, 17% TDM), and internal iliac arteries (1/17, 6% TDM). Estimated blood loss varied widely and was not significantly different between vessel groups (p = 0.280). Overall, 44 of 60 (73%) patients had negative margins. Fourteen patients (23%) returned to the operating room, most for wound infection or dehiscence. Mean follow-up was 20.25 months (range: 0.5-122.0 months, SD: 23 months). Forty patients were followed up for more than 1 year. Thus, with an overall median follow-up of 12.25 months, overall survival was 60% with disease-free survival of 40%. CONCLUSIONS: Resection of tumors involving the aorta and major arterial structures provides a reasonable option for treatment, but with significant perioperative morbidity. In selected patients, this aggressive intervention should be considered.

Contemporary management of aberrant right subclavian arteries.

BACKGROUND: Aberrant origin of right subclavian arteries represents the most common of the aortic arch anomalies. This variant has few published series to guide management. Our goal was to review treatment options and results for these potentially complex reconstructions. METHODS: A retrospective review was performed on all patients with a diagnosis of aberrant right subclavian artery at our institution between January 2003 and July 2009. RESULTS: A total of 24 patients, which comprises one of the largest series reported, including 10 males and 14 females (mean age: 46.6 years, range: 7-77), were diagnosed with an aberrant right subclavian artery. Sixteen (66%) were diagnosed incidentally, but eight (33%) had symptoms of either dysphagia, upper extremity ischemia, or both. Computed tomography was most commonly used to establish the diagnosis (19 patients, 79%). Magnetic resonance imaging established the diagnosis in three patients (12%), upper gastrointestinal barium study in one (4%), and standard angiography in one (4%). A Kommerell's diverticulum (KD) was the most common associated anomaly (seven patients, 29%). All seven patients (100%) with a KD required intervention for either symptoms or aneurysmal degeneration. Intervention was performed in 10 patients (42%), including carotid subclavian bypass in five (50%), carotid subclavian transposition in three (30%), and ascending aorta to subclavian bypass in two (20%). Four patients (40%) had additional intervention for management of aneurysmal disease of the aorta or KD, with open aortic replacement in two (20%) and aortic endografting in two (20%). There was one perioperative death (10%) in a patient undergoing aortic arch debranching with placement of an aortic endograft. In all, 18 patients survived without symptoms after a mean follow-up of 38 months. CONCLUSIONS: Aberrant right subclavian arteries are most commonly found incidentally with computed tomography. The presence of a KD seemed to correlate with the need for intervention. Patients with no symptoms with the absence of a KD can safely be followed.

Urinary bladder injuries during vascular surgery.

Urologic complications related to vascular surgery involving the ureter have been well recognized. These include ureteral compression from aneurysms, congenital anomalies such as retrocaval ureter, obstruction from retroperitoneal fibrosis, iatrogenic injury, and ureteric fistulas. Complications involving the bladder are more infrequent. Most of these bladder-related complications involve the use of tunneling devices for synthetic bypass grafts. We report an unusual case of a transvesically placed femoral-femoral bypass graft with delayed presentation. We also reviewed the English literature for experience with diagnosis and treatment of bladder injuries during vascular surgical procedures.

Safety of carotid endarterectomy in patients concurrently on clopidogrel.

BACKGROUND: Clopidogrel (Plavix) usage is increasing, primarily for the management of patients with cerebrovascular symptoms and for those receiving drug-eluting coronary artery stents. A significant percentage of these patients will require carotid endarterectomy (CEA) while they are receiving clopidogrel. Recent data have demonstrated an increased incidence of coronary stent thrombosis when clopidogrel is discontinued. The objective of this study was to determine if CEA could be performed safely while patients are continued on clopidogrel therapy. METHODS: A retrospective cohort design was employed to review consecutive patients who underwent CEA over a 24-month period ending March 2007. Patients were divided into two groups based on the perioperative use of clopidogrel. Preoperative demographics and postoperative results were compared between the two groups and statistically analyzed. RESULTS: Of the 100 patients who underwent CEA, 19 were taking clopidogrel within 5 days of surgery. This comprised the study group. The control group consisted of the 81 patients who did not receive clopidogrel. Heparin anticoagulation was routinely utilized prior to clamping in both groups. Demographics were similar between the groups. There were no statistical differences in morbidity or mortality between the control group and the clopidogrel group. Combined stroke/death rates were equivalent between the two groups (1.2% control vs. 0% clopidogrel). One hematoma developed in the control group, which did not require operative intervention. CONCLUSION: In this series, our results suggest that patients concurrently on clopidogrel can safely undergo CEA without increased risk of hematoma or neurological complications. In view of recent data demonstrating adverse outcomes in patients discontinuing clopidogrel, this study is useful in optimally managing this group of patients.

Successful repair of a popliteal aneurysm with saphenous vein graft in a patient with Marfan syndrome.

Marfan syndrome is an autosomal dominant disorder caused by mutations in the fibrillin 1 gene (FBN1). This leads to defective elasticity of connective tissue in the arterial wall. Aortic aneurysms and dissections are the most common vascular anomalies; the incidence of peripheral artery aneurysms is not well understood. Treatment options for infrainguinal disease are limited as endovascular interventions are generally contraindicated. The best conduit for arterial reconstruction is also unknown because there is concern that saphenous vein may become aneurysmal. Currently, there are few case reports regarding outcomes of infrainguinal arterial reconstructions, and follow-up has been very short term. We report a rare case of successful repair of a popliteal aneurysm using a saphenous vein graft in a patient with Marfan syndrome.

Type 3 phosphodiesterase inhibitors may be protective against cerebrovascular events in patients with claudication.

OBJECTIVE: The risk of cerebrovascular events in patients with mild to moderate peripheral vascular disease is significant. Cilostazol is a phosphodiesterase type 3 (PDE3) inhibitor that is effective in the treatment of symptoms of peripheral arterial occlusive disease. The method of action includes antithrombotic, vasodilatory, and antiproliferative effects. METHODS: The Cilostazol: A Study in Long-Term Effects (CASTLE) trial was a prospective randomized double-blinded trial to establish the safety of this PDE3 inhibitor use in 1435 patients with mild to moderate peripheral arterial occlusive disease. A post hoc analysis of the CASTLE trial was undertaken to evaluate cilostazol use on cerebrovascular events. Blinded adjudication of all cerebrovascular events (stroke, transient ischemic attack, and carotid revascularization) in this trial was performed. Kaplan-Meier analysis was used for statistical evaluation. RESULTS: The overall rate of cerebrovascular events was 4.6% (67 of 1435 patients) with a mean follow-up of 515 days. Ischemic vascular events were more common (2.5%) than hemorrhagic events (0.3%; P < .05). The placebo group demonstrated a greater risk for events (6.1%; 43 of 718 patients) versus the cilostazol treated group (3.2%; 24 of 717 patients; P < .05). Cerebrovascular risk factors were similar in both groups. CONCLUSION: The risk of cerebrovascular events in patients with mild to moderate peripheral arterial occlusive disease is 4.6% with a mean follow-up of 515 days. Treatment with PDE3 inhibitors may reduce this risk. Further evaluation of the use of PDE3 inhibitors for prevention of cerebrovascular events should be considered.

Robotic inferior vena cava surgery.

OBJECTIVE: Inferior vena cava (IVC) surgery is uncommon and has traditionally been performed through open surgical approaches. Renal cell carcinoma with IVC extension generally requires vena cavotomy and reconstruction. Open removal of malpositioned IVC filters (IVCF) is occasionally required after endovascular retrieval attempts have failed. As our experience with robotic surgery has advanced, we have applied this technology to surgery of the IVC. We reviewed our institution's experience with robotic surgical procedures involving the IVC to determine its safety and efficacy. METHODS: All patients undergoing robotic surgery that included cavotomy and repair from 2011 to 2014 were retrospectively reviewed. Data were obtained detailing preoperative demographics, operative details, and postoperative morbidity and mortality. RESULTS: Ten patients (6 men) underwent robotic vena caval procedures at our institution. Seven patients underwent robotic nephrectomy with removal of IVC tumor thrombus and retroperitoneal lymph node dissection. Three patients underwent robotic explantation of an IVCF after multiple endovascular attempts at removal had failed. The patients with renal cell carcinoma were a mean age of was 65.4 years (range, 55-74 years). Six patients had right-sided malignancy. All patients had T3b lesions at time of diagnosis. Mean tumor length extension into the IVC was 5 cm (range, 1-8 cm). All patients underwent robotic radical nephrectomy, with caval tumor thrombus removal and retroperitoneal lymph node dissection. The average operative time for patients undergoing surgery for renal cell carcinoma was 273 minutes (range, 137-382 minutes). Average intraoperative blood loss was 428 mL (range, 150-1200 mL). The patients with IVCF removal were a mean age of 33 years (range, 24-41 years). Average time from IVCF placement until robotic removal was 35.5 months (range, 4.3-57.3 months). Before robotic IVCF removal, a minimum of two endovascular retrievals were attempted. Average operative time for patients undergoing IVCF removal was 163 minutes (range, 131-202 minutes). Intraoperative blood loss averaged 250 mL (range, 150-350 mL). All procedures were completed robotically. The mean length of stay for all patients was 3.5 days (range, 1-8 days). All patients resumed ambulation on postoperative day 1. Nine patients resumed a regular diet on postoperative day 2. One patient with a renal tumor sustained a colon injury during initial adhesiolysis, before robotic radical nephrectomy, which was recognized at the initial operation and repaired robotically. Robotic radical nephrectomy and caval tumor removal were then completed. No blood transfusions were required intraoperatively, but three patients required blood transfusions postoperatively. CONCLUSIONS: Although robotic IVC surgery is uncommon, our initial limited experience demonstrates it is safe and efficacious.

Transducible recombinant small heat shock-related protein, HSP20, inhibits vasospasm and platelet aggregation.

BACKGROUND: Human saphenous vein (HSV) is the autologous conduit of choice for peripheral vascular reconstruction. Injury during harvest leads to vasospasm and a thrombogenic endoluminal surface. A proteomic transduction approach was developed to prevent vein graft vasospasm and thrombosis. METHODS: Recombinant HSP20 protein linked to the TAT protein transduction domain was generated in a bacterial expression system (TAT-HSP20). The effect of this protein on the inhibition of smooth muscle contraction was determined using rings of rabbit aorta and HSV in a muscle bath. In addition, the effects of TAT-HSP20 on platelet aggregation were determined in vitro using human citrated whole blood. RESULTS: Recombinant TAT-HSP20 inhibited norepinephrine-induced contraction of rabbit aortic and HSV segments. Similarly, TAT-HSP20 induced smooth muscle relaxation in HSV segments precontracted with norepinephrine. In human-citrated whole blood, platelet aggregation was significantly inhibited by TAT-HSP20 in a dose-dependent manner. CONCLUSIONS: The results of this study demonstrate that recombinant TAT-HSP20 inhibits vascular smooth muscle contraction and platelet aggregation. This suggests that HSP20 may be an ideal effector molecule to target as a proteomic approach to enhance early vein graft patency rates by preventing acute vasospasm and thrombosis.