Timothy K. Liem

Peripherally inserted central catheter usage patterns and associated symptomatic upper extremity venous thrombosis

OBJECTIVES Peripherally inserted central catheters (PICCs) may be complicated by upper extremity (UE) superficial (SVT) or deep venous thrombosis (DVT). The purpose of this study was to determine current PICC insertion patterns and if any PICC or patient characteristics were associated with venous thrombotic complications. METHODS All UE venous duplex scans during a 12-month period were reviewed, selecting patients with isolated SVT or DVT and PICCs placed ≤30 days. All UE PICC procedures during the same period were identified from an electronic medical record query. PICC-associated DVTs, categorized by insertion site, were compared with all first-time UE PICCs to determine the rate of UE DVT and isolated UE SVT. Technical and clinical variables in patients with PICC-associated UE DVT also were compared with 172 patients who received a PICC without developing DVT (univariable and multivariable analysis). RESULTS We identified 219 isolated UE SVTs and 154 UE DVTs, with 2056 first-time UE PICCs placed during the same period. A PICC was associated with 44 of 219 (20%) isolated UE SVTs and 54 of 154 UE DVTs (35%). The rates of PICC-associated symptomatic UE SVT were 1.9% for basilic, 7.2% for cephalic, and 0% for brachial vein PICCs. The rates of PICC-associated symptomatic UE DVT were 3.1% for basilic, 2.2% for brachial, and 0% for cephalic vein PICCs (χ(2)P < .001). Univariate analysis of technical and patient variables demonstrated that larger PICC diameter, noncephalic insertion, smoking, concurrent malignancy, diabetes, and older age were associated with UE DVT (P < .05). Multivariable analysis showed larger catheter diameter and malignancy were the only variables associated with UE DVT (P < .05). CONCLUSIONS The incidence of symptomatic PICC-associated UE DVT is low, but given the number of PICCs placed each year, they account for up to 35% of all diagnosed UE DVTs. Larger-diameter PICCs and malignancy increase the risk for DVT, and further studies are needed to evaluate the optimal vein of first choice for PICC insertion.

Utility of direct angiosome revascularization and runoff scores in predicting outcomes in patients undergoing revascularization for critical limb ischemia

OBJECTIVE Both runoff scores and direct (DR) vs indirect revascularization (IR) according to pedal angiosomes have unclear impact on outcome for patients with critical limb ischemia (CLI). We compared DR vs IR and runoff scores in CLI patients undergoing infrapopliteal bypass for foot wounds. METHODS Patients who had tibial/pedal bypass for a foot/ankle wound from 2005-2011 were identified and operations classified as DR or IR based on wound location and bypass target. A blinded observer reviewed angiograms for an intact pedal arch and calculated standard Society for Vascular Surgery (single tibial) and modified (composite tibial) runoff scores. Comorbidities, wound characteristics, wound healing, major amputation, and overall survival were determined. RESULTS A total of 106 limbs were revascularized in 97 patients; 54 limbs had DR and 52 had IR, although only 36% of wounds corresponded to a single, distinct angiosome. Wound characteristics and comorbidities were similar between groups. Mean standard (7.9 vs 7.2; P = .001) and modified (22.2 vs 20.0; P = .02) runoff scores were worse (higher number indicates worse runoff) in the IR vs DR groups; 33% had a complete pedal arch. Complete wound healing (78% vs 46%; P = .001) and time to complete healing (99 vs 195 days; P = .002) were superior with DR vs IR but were not influenced by runoff score, modified runoff score or presence of complete plantar arch. In multivariate models controlling for runoff score, DR remained a significant predictor for wound healing (odds ratio, 2.9; 95% confidence interval, 1.1-7.4; P = .028) and reduced healing time (hazard ratio, 2.1; 95% confidence interval, 1.2-3.7; P = .012). Mean amputation-free survival (75 vs 71 months for DR vs IR; P = .82) and median survival (36 vs 33 months DR vs IR; P = .22) were not different for DR vs IR. CONCLUSIONS DR according to pedal angiosomes provides more efficient wound healing, but is possible in only one-half of the patients and does not affect amputation-free or overall survival. DR is associated with improved runoff scores, but current runoff scores have little clinical utility in predicting outcomes in CLI patients.

Characterizing resolution of catheter-associated upper extremity deep venous thrombosis

OBJECTIVE Catheter-associated upper extremity deep venous thrombosis (CAUEDVT) is well known; however, resolution rates and factors affecting resolution of CAUEDVT are not well characterized. This study determined resolution rates and factors associated with resolution of CAUEDVT. METHODS From January 1, 2002, to June 30, 2006, 1761 upper extremity venous duplex ultrasound (DU) studies were performed, and a new UEDVT was found in 253 (14.4%). Of these, 150 patients had routine follow-up and 101 had CAUEDVT. Demographics, follow-up DU results, and risk factors for venous thrombosis were recorded in the patients with follow-up studies and CAUEDVT. Univariate analysis and multivariate logistic regression analysis was performed to determine independent risk factors for complete thrombus resolution. RESULTS There were 49 men (49%) and 52 women (51%) with CAUEDVT and follow-up studies. Mean age was 49 years (range, 5 months-80 years). Patients with CAUEDVT had risk factors for venous thrombosis that included malignancy in 34%, recent surgery/trauma in 34%, known hypercoagulable state in 11%, concomitant lower extremity DVT in 21%, and pulmonary embolism in 5%. Complete resolution of DVT on follow-up was documented in 46%. Thrombosis resolved in only 25% (6 of 24) when the catheter was not removed (P <or= .05). Anticoagulation did not improve the rate of thrombus resolution (P <or= 1.0) compared with catheter removal alone. Of the patients who had thrombus resolution, 75% resolved by 100 days (range, 1-914 days) after catheter removal <or=48 hours of diagnosis. In multivariate analysis, only catheter removal predicted the likelihood of thrombus resolution (odds ratio, 3.25; 95% confidence interval, 1.16-9.09; P = .025). New-site UEDVT developed in 86% of patients with CAUEDVT who underwent catheter removal and immediate catheter placement in a new site. Pulmonary embolism developed in five patients with CAUEDVT. Of these, three had documented lower extremity DVT as well. No pulmonary emboli were fatal. CONCLUSIONS More than half of CAUEDVT resolve <or=113 days when the catheter is removed <or=48 hours of diagnosis. New-site catheter placement has a high rate of new associated UEDVT. Anticoagulation does not appear to augment resolution of UEDVT.

Duplex criteria for native superior mesenteric artery stenosis overestimate stenosis in stented superior mesenteric arteries

OBJECTIVES Superior mesenteric artery (SMA) duplex scanning is utilized to screen for high-grade (>or=70%) SMA stenosis (peak systolic velocity [PSV] >or=275 cm/second) and for follow-up of SMA bypass grafts and stents. Expected duplex scan findings in SMA bypass grafts have been recently reported. There is, however, little information correlating duplex scans from stented SMAs to procedural angiograms in patients treated for high-grade (>or=70%) SMA stenosis. We report validation of duplex scan criteria for high-grade native artery SMA stenosis, and also duplex scan examined results after SMA stent placement correlated with angiograms and angiographic measured pressure gradients pre- and post-SMA stent placement. METHODS AND RESULTS Thirty-five patients with symptoms consistent with mesenteric ischemia were treated with SMA stents. Pre-intervention angiography demonstrated >70% SMA stenosis or SMA occlusion in all but 3 patients. Pre-intervention pressure gradients were obtained in 20 stenotic but patent SMAs and averaged 57 +/- 38 mm Hg; range, 15 to 187 mm Hg. Eighteen of the patients had SMA duplex scan prior to angiography, and 17 demonstrated an SMA PSV >or=275 cm/second or no flow, (mean 450 +/- 152 cm/second in patent arteries; range, 256 to 770 cm/second). Post-stent placement angiography demonstrated <30% SMA stenosis in all 35 patients. Post-stent pressure gradients were obtained in 22 patients and averaged 11 +/- 13 mm Hg; range, 0 to 45 mm Hg, (P < .001 compared to pre-stent pressure gradients in a paired test) and were elevated in patients with >or=60% celiac artery stenosis compared with those with <60% celiac artery stenosis (P < .006). Mean early post-stent duplex PSV scans obtained in 13 patients, were 336 +/- 45 cm/second; range, 279 to 416 cm/second (P = .011 compared to pre-stent PSVs). CONCLUSION SMA stenting provides good anatomic results and significantly reduces measured pressure gradients. Duplex scans measured SMA PSVs are reduced post-stent placement but despite good angiographic results remain above criteria predicting high-grade native artery SMA stenosis. Duplex scan criteria developed to identify high-grade native artery SMA stenosis accurately predict high-grade native artery SMA stenosis but overestimate stenosis in stented SMAs. New duplex scan criteria are required to predict high-grade stenosis in stented SMAs.

Improving the quality of the surgical morbidity and mortality conference: a prospective intervention study.

Purpose Surgical morbidity and mortality conferences (M&MCs) provide surgeons with an opportunity to confront medical errors, discuss adverse events, and learn from their mistakes. Yet, no standardized format for these conferences exists. The authors hypothesized that introducing a standardized presentation format using a validated framework would improve presentation quality and educational outcomes for all attendees. Method Following a review of the literature and the solicitation of experts’ opinions, the authors adapted a validated communication tool—the SBAR (Situation, Background, Assessment, Recommendations) framework. In 2010, they then introduced this novel standardized presentation format into the surgical M&MCs at the Oregon Health & Science University. The authors assessed three outcome measures—user satisfaction, presentation quality, and education outcomes—before and after implementation of their standardized presentation format. Results Over the six-month study period, residents delivered 66 presentations to 197 faculty, resident, and medical student attendees. Attendees’ performance on the multiple-choice questionnaires improved after the intervention, indicating an improvement in their knowledge. Presentation quality also improved significantly after the intervention, according to evaluations by trained faculty assessors. They noted specific improvements in the quality of the Background, Assessment, and Recommendation sections. Conclusions The M&MC plays a pivotal role in educating residents and improving patient safety. Standardizing the M&MC presentation format using an adapted SBAR framework improved the quality of residents’ presentations and attendees’ educational outcomes. The authors recommend using such a standardized presentation format to enhance the educational value of M&MCs, with the goal of improving surgeons’ knowledge, skills, and patient care practices.

Open abdominal aortic aneurysm repair in the endovascular era: Effect of clamp site on outcomes

OBJECTIVE To describe a contemporary series of open abdominal aortic aneurysm (AAA) repairs in patients not anatomically suitable for endovascular AAA repair. METHODS A prospectively maintained database including consecutive nonruptured open aneurysm repairs from March 1, 2000, through July 31, 2007, was reviewed. Patient demographic characteristics and perioperative outcomes were evaluated and stratified based on proximal aortic cross-clamp placement. RESULTS A total of 185 patients with AAA underwent 103 infrarenal and 82 suprarenal cross-clamp repairs. Overall, the complication rate was 37.0% with infrarenal and 61.0% with suprarenal cross-clamps (P = .001). The 30-day mortality was 2.9% with infrarenal and 6.1% with suprarenal cross-clamps (P = .18). Postoperative renal insufficiency (29.3% vs 7.8%; P < .001) and pulmonary complications (25.6% vs 12.6%; P = .03) were more frequent with suprarenal cross-clamps. Suprarenal cross-clamps were associated with greater intraoperative blood loss (2586 mL vs 1638 mL; P = .006), operative duration (391 min vs 355 min; P = .005), use of adjunctive renal and/or visceral grafts (43.9% vs 1.9%; P < .001), duration of intensive care unit stay (4.5 days vs 3.0 days; P = .006), and hospital length of stay (9 days vs 7 days; P = .04). Of patients who received a suprarenal cross-clamp, 25.6% required temporary nursing home placement vs 17.5% with an infrarenal cross-clamp (P = .14). CONCLUSIONS Until fenestrated and branched endografts are available, open AAA repairs will become increasingly complex. Suprarenal cross-clamping is associated with increased rates of complications but similar mortality rates and need for nursing home placement. With the disappearance of straightforward open aneurysm repair, trainees in vascular surgery will have to learn AAA repair almost exclusively by operating on patients with complex AAAs. Fewer surgeons will perform these repairs, and fewer fellows will be able to complete the operation independently immediately after training.

Predictors of healing and functional outcome following transmetatarsal amputations.

OBJECTIVES To evaluate factors that predict healing and to assess functional outcome and survival following transmetatarsal amputations (TMAs) for forefoot gangrene. DESIGN Retrospective case-control study. SETTING University hospital. PATIENTS All patients undergoing TMA from January 1, 2004, through December 31, 2010. INTERVENTION Transmetatarsal amputations performed in all patients. MAIN OUTCOME MEASURES Transmetatarsal amputation healing, ambulation, living status, and survival. Demographic characteristics, preoperative vascular status, and perioperative variables were analyzed as predictor variables. Univariate and multivariate analyses were performed to determine predictors of healing and survival. RESULTS Sixty-two TMAs were performed in 57 patients. Healing occurred in 33 TMAs (53%), with 22 TMAs (35%) in patients who proceeded to below-knee amputation and 7 TMAs (11%) in patients who died without healing. No demographic or perioperative variables significantly predicted healing. Independent ambulation was achieved in 24 patients with healed TMAs (73%) but in only 4 patients with nonhealed TMAs (14%) (P < .001). Mean survival was 16.5 months (range, 0-94 months), with no difference between patients with healed and those with nonhealed TMA. Significant predictors of mortality were dialysis-dependent renal failure (odds ratio, 4.85; 95% confidence interval, 1.01-23.30) (P = .047), nonindependent living (17.80; 3.03-104.80) (P = .001), and need for preoperative revascularization (4.80; 1.24-18.50) (P = .02). CONCLUSIONS Transmetatarsal amputations have low healing rates, and patient demographic characteristics and preoperative assessment do not help predict healing. Transmetatarsal amputation healing, however, significantly predicts subsequent ambulatory status and should be pursued in patients with good rehabilitation potential.

Techniques and results of portal vein/superior mesenteric vein reconstruction using femoral and saphenous vein during pancreaticoduodenectomy

BACKGROUND Patients with pancreatic tumors may have portal vein (PV) and/or superior mesenteric vein (SMV) invasion. In such cases, lower extremity veins can provide an autogenous conduit for PV/SMV reconstruction. Little data exist, however, describing the technique of PV/SMV reconstruction, patency of such reconstructions, and the morbidity of using lower extremity veins for PV/SMV reconstruction during pancreaticoduodenectomy. METHODS Thirty-four patients underwent PV/SMV reconstruction during pancreaticoduodenectomy using lower extremity vein. The saphenous vein was preferred for patching and femoral vein for replacement. We analyzed preoperative imaging, reconstruction patency, vein harvest morbidity, and late mortality. RESULTS The mean age was 62.6 years. All 34 patients had preoperative computed tomography (CT) imaging and/or endoscopic ultrasound (EUS) scan. Fourteen of the 34 patients had evidence of PV/SMV invasion on CT or EUS scans, 14 did not, and six studies were indeterminate. Twenty-five patients had follow-up imaging, and 22 (88%) had patent reconstructions. Fifteen patients had PV/SMV replacement using femoral vein. Seven of these 15 had minor postoperative lower extremity edema that resolved over time, five had wound complications from the femoral vein harvest site, three of which required minor operative procedures for treatment. Fifteen patients had PV/SMV patching with the great saphenous vein, none had postoperative wound problems, and one had minimal postoperative lower extremity edema. Four patients had PV/SMV patching using femoral vein, none had postoperative wound problems, and one had minimal postoperative lower extremity edema. Compared with patients undergoing pancreaticoduodenectomy without PV/SMV reconstruction, by Kaplan-Meier analysis, there was no difference in late mortality. CONCLUSION Preoperative imaging may fail to detect PV/SMV involvement in patients undergoing pancreaticoduodenectomy. The PV/SMV reconstruction with leg vein provides good patency with minimal postoperative lower extremity complications and no increase in late mortality. The lower extremities should be routinely included in the operative field of patients undergoing pancreaticoduodenectomy.

Compliance With Long-Term Surveillance Recommendations Following Endovascular Aneurysm Repair or Type B Aortic Dissection

OBJECTIVE Lifelong surveillance is recommended for both endovascular aneurysm repair and acute, uncomplicated type B thoracic aortic dissection, though compliance remains a significant challenge. We sought to determine factors associated with failure to obtain recommended surveillance. METHODS Patients surviving to discharge who had endovascular repair of thoracic (thoracic endovascular aortic aneurysm repair [TEVAR]) or abdominal aortic aneurysms (endovascular aortic aneurysm repair [EVAR]) or medical management for type B dissections from 2004-2011 were reviewed. Primary end points were compliance with follow-up and need for reintervention. Comorbidities examined included coronary artery disease, congestive heart failure, hypertension, chronic obstructive pulmonary disease, diabetes, and chronic kidney disease. Socioeconomic factors examined were age, sex, distance from hospital, discharge destination (ie, home or skilled nursing facility), and insurance type. Endoleak and sac expansion were recorded, as were complications, including endograft migration, infection or thrombosis, and aneurysm degeneration. RESULTS Two hundred four patients, median age 71.9 years, were identified; 171 had EVAR and 33 had type B dissection. EVAR patients included 45 thoracic, 100 abdominal, and 12 thoracoabdominal endografts, as well as 7 iliac artery aneurysm repairs and 7 proximal/distal graft extensions. Median follow-up was 28 ± 10.5 months. Overall, 56% were lost to follow-up, whereas 11% never returned for surveillance after initial hospitalization. Follow-up was compared for each of the comorbidities and socioeconomic factors; none were found to significantly affect follow-up. The known complication rate was 9.3% (n = 19), with reintervention performed in 14% of EVAR/TEVAR patients. Thirty-eight percent of medically managed patients with type B dissections eventually required surgical intervention. All-cause 5-year mortality was 27% as determined by the Social Security Death Index. CONCLUSIONS Despite a significant rate of reintervention following EVAR, TEVAR, and type B dissection, long-term compliance with surveillance is limited. In addition, predicting who is at risk of being lost to follow-up remains difficult. If current recommendations for lifelong surveillance are to be followed, coordinated protocols are required to capture EVAR, TEVAR, and type B dissection patients to ensure optimal follow-up for these patients. However, the lack of survival benefit in those with complete follow-up suggests that further study is needed with regard to ideal duration of long-term follow-up.

SBAR M&M: a feasible, reliable, and valid tool to assess the quality of, surgical morbidity and mortality conference presentations.

BACKGROUND The Surgical Morbidity and Mortality (M&M) conference is considered the golden hour of surgical education. However, evaluation methods for ensuring that quality M&M presentations efficiently contribute to resident education have not been clearly defined. To provide surgical trainees with the skills required to present a quality M&M presentation it is essential to have a robust tool to measure presentation skill and guide formative feedback. METHODS A prospective observational study was conducted to develop an assessment tool for M&M conference. Literature review and expert consensus provided content for tool development. The tool, created using the situation, background, assessment, and recommendation format, was refined successively based on assessor feedback and assessed for reliability (internal consistency, interassessor reliability) and construct validity. RESULTS Three successive iterations of the tool were developed. Internal consistency and interassessor reliability improved from the first to third versions. A trend also was shown for increasing construct validity with the third iteration of the tool. CONCLUSIONS A psychometrically robust assessment tool based on the situation, background, assessment, and recommendation format was developed and validated to identify and improve the overall quality and educational value of the surgical M&M conference.