Andrew Barleben

Incidence and Risk Factors of Venous Thromboembolism in Colorectal Surgery Does Laparoscopy Impart an Advantage

OBJECTIVES Laparoscopy is increasingly used in colon and rectal procedures. However, little is known regarding the incidence of venous thromboembolism (VTE) in laparoscopic colorectal (LC) compared with that in open colorectal (OC) procedures. We aimed to compare the incidences and to highlight the risk factors of developing VTE after LC and OC surgery. DESIGN Analysis of the Nationwide Inpatient Sample data from 2002 through 2006. SETTING National database. PATIENTS Patients who underwent elective LC and OC surgery from 2002 through 2006. MAIN OUTCOMES MEASURE Incidence of VTE during initial hospitalization after LC and OC surgery; VTE classified by surgical site, pathology type, and at-risk patient population. RESULTS Over a 60-month period, 149,304 patients underwent LC or OC resection. Overall, the incidence of VTE was significantly higher in OC cases (2036 of 141,456 [1.44%]) compared with the incidence in LC cases (65 of 7848 [0.83%]) (P < .001). When stratified according to pathologic condition and surgical site, the overall rate of VTE was highest in patients with inflammatory bowel disease and in those undergoing rectal resections. Patients who underwent OC surgery were almost twice as likely to develop VTE compared with patients who underwent LC surgery. We also identified malignancy, obesity, and congestive heart failure as statistically significant (P < .05) risk factors for VTE in OC and LC surgery. CONCLUSIONS On the basis of data from a large clinical data set, the incidence of perioperative VTE is lower after LC than after OC surgery. These findings may help colorectal surgeons use appropriate VTE prophylaxis for patients undergoing colorectal procedures.

Anorectal Anatomy and Physiology

The rectum and anal canal form the last portion of the gastrointestinal tract. The rectum serves as a reservoir for fecal contents, and the anal canal regulates continence and defecation via synchronization of events regulated by complex interactions between sympathetic and parasympathetic nerves, striated and smooth muscle, and environmental factors. Normal function can be compromised by various pathologies. Investigation into these pathologies includes a detailed history and thorough physical exam and can be augmented by a number of different studies, including manometry, electromyelography, defecography, nerve stimulation, and compliance. Some of these techniques have incorporated the use of ultrasound and magnetic resonance imaging.

Population-based evaluation of adenosquamous carcinoma of the colon and rectum.

BACKGROUND: Information about adenosquamous carcinoma of the colon and rectum is scarce because of its extremely low incidence. OBJECTIVE: The aim of this study was to examine the prognostic significance of a histological diagnosis of adenosquamous carcinoma in comparison with adenocarcinoma of the colon and rectum. DESIGN: This study was retrospective in design. SETTING: California Cancer Registry data from 1994 through 2004 with follow–up through 2008 were analyzed. PATIENTS: Patients were included whose cancer of the colon and rectum, excluding the anus with a tumor histology of adenocarcinoma and adenosquamous carcinoma, was surgically treated. MAIN OUTCOME MEASURES: The primary outcomes measured were histology–specific survival analyses (with the use of the Kaplan–Meier method), and overall and colorectal–specific mortality (with the use of multivariable Cox proportional hazards regression analyses). RESULTS: A total of 111,263 adenocarcinoma and adenosquamous carcinoma of colon and rectal cancer cases were identified (adenocarcinoma, 99.91%; adenosquamous carcinoma, 0.09%). There was no significant difference in sex, age, race, and socioeconomic status between the 2 groups. The most common location of adenocarcinoma and adenosquamous carcinoma was the right and transverse colon. The adenosquamous carcinoma group was significantly associated with a higher rate of metastasis at the time of operation (adenosquamous carcinoma, 36.56% vs adenocarcinoma, 13.92%) and with poorly differentiated tumor grade (adenosquamous carcinoma, 65.96% vs adenocarcinoma, 19.74%) in comparison with the adenocarcinoma group. The median overall survival time was significantly greater in the adenocarcinoma group (82.4 months) in comparison with the adenosquamous carcinoma group (35.3 months). With the use of multivariable hazard regression analyses, adenosquamous carcinoma histology was independently associated with increased overall mortality (hazard ratio, 1.67) and colorectal–specific mortality (hazard ratio, 1.69) in comparison with adenocarcinoma. CONCLUSIONS: This is one of the largest studies of adenosquamous carcinoma of the colon and rectum to date. This uncommon colorectal cancer subtype was associated with higher overall and colorectal–specific mortality in comparison with adenocarcinoma. Among colorectal cancer cases, adenosquamous carcinoma histology should be considered a poor prognostic feature.

Implementation of a cost-saving algorithm for pelvic radiographs in blunt trauma patients

BACKGROUND In a previous retrospective study, we demonstrated that pelvic radiographs (PXRs) in the evaluation of blunt trauma patients undergoing abdominal computed tomographic (CT) scanning have limited utility in the absence of hemodynamic instability and significant physical findings. The purpose of this study was to prospectively validate an algorithm defining indications for PXR in blunt trauma patients in the emergency department. METHODS We performed a prospective observational study of consecutive blunt trauma patients over 6 months at a single Level 1 trauma center. The trauma faculty agreed to implement an algorithm of obtaining PXRs in patients undergoing abdominal CT scanning only if a specific set of criteria were met: systolic blood pressure <90 mm Hg, hemoglobin <8 mg/dL, a drop in Hgb of more than 3 mg/dL while in the trauma bay, or significant physical examination findings. The algorithm could be overridden at the discretion of the attending physician. RESULTS Nine hundred ninety-five consecutive blunt trauma patients whose evaluation was to include an abdominal CT scan were included in the study. Only 54 patients (6%) received a PXR. Fifty-six indications for PXR were provided: 35 (63%) severe pelvic pain, 14 (25%) proximal fractures, 3 (5%) hip dislocations, and only 4 (7%) had unexplained hypotension. No adverse events or delays in care occurred such as hypotension in the CT scanner or a delay in contacting interventional radiology, blood transfusion, or application of a pelvic binder. The algorithm selected PXR for patients who were more likely to have a pelvic fracture (33% vs. 4.5%, p < 0.001), hip dislocation (7.4% vs. 0.1%, p < 0.001), femur fracture (22.2% vs. 2.7%, p < 0.001), and to require blood transfusion (11.1% vs. 1.9%, p < 0.001). Implementation of this algorithm resulted in a decrease in charges of >

Comparative safety of endovascular aortic aneurysm repair over open repair using patient safety indicators during adoption.

226,000 in 6 months. CONCLUSION When objective evaluation of the abdomen is to be obtained via CT scanning, PXR in the emergency department is obsolete in the absence of hemodynamic instability and significant physical examination findings. Implementation of a selective algorithm in this patient population can result in significant cost savings without adverse patient outcomes.

Intraprocedural and postprocedural perigraft arterial sac embolization (PASE) for endoleak treatment

IMPORTANCE In 2003, the Agency for Healthcare Research and Quality established Patient Safety Indicators (PSIs) to monitor preventable adverse events during hospitalizations. OBJECTIVE To evaluate the comparative safety of endovascular aneurysm repair (EVAR) vs open aneurysm repair (OAR) of abdominal aortic aneurysm by measuring PSIs associated with each procedure over time. DESIGN, SETTING, AND PARTICIPANTS Cases of abdominal aortic aneurysm repair were extracted from the Nationwide Inpatient Sample (2003-2010). Patient Safety Indicators were calculated using Agency for Healthcare Research and Quality software (Win QI, version 4.4). Unadjusted analysis included year, age, sex, race/ethnicity, comorbidities, rupture status, hospital teaching status, and emergency status. Multivariable analysis was stratified by year for any PSI in EVAR vs OAR. Postoperative mortality was analyzed to control for the overall safety. MAIN OUTCOMES AND MEASURES Patient Safety Indicators and mortality. RESULTS In total, 43,385 EVARs and 27,561 OARs were documented, with 1289 (3.0%) and 3094 (11.2%) associated PSIs, respectively. Compared with those receiving OAR, patients receiving EVAR were more likely to be male, older, and of white race/ethnicity; have a lower Charlson Comorbidity Index; and seek care at teaching hospitals (P < .001 for all). Patients were less likely to have a PSI after EVAR than after OAR. Overall, multivariable analysis showed that EVAR was associated with a 42.1% decrease in the risk-adjusted odds of any PSI compared with OAR (odds ratio, 0.58; 95% CI, 0.51-0.65). Stratified by year, the risk-adjusted odds of any PSI after EVAR were comparatively less likely than after OAR every year except for 2007, and the odds of death were comparatively less every year. The annual percentage of PSIs among all aortic repairs decreased from 7.4% in 2003 to 4.4% in 2010, while the proportion of total repairs that were EVARs increased from 41.1% in 2003 to 75.3% in 2010. CONCLUSIONS AND RELEVANCE Patient Safety Indicators can be used to monitor the comparative safety of emerging surgical technologies. Herein, EVAR was safer than OAR. The adoption of minimally invasive technology can improve safety among surgical admissions.

Congenital Agenesis of Inferior Vena Cava: A Rare Cause of Unprovoked Deep Venous Thrombosis

Intervention may be necessary in up to one-third of patients with endoleaks after endovascular aortic aneurysm repair (EVAR). Perigraft arterial sac embolization (PASE) to induce aneurysm thrombosis was performed by intrasac injection of thrombin and gelfoam slurry. Thirteen patients were treated with PASE since 2006. Eight patients underwent immediate PASE, and five patients were treated during surveillance following EVAR. The median follow-up is 23.9 months (range, 2.6-66.1 months) for the entire cohort; 24.4 and 23.1 months for the immediate and delayed group, respectively. No patients had further aneurysm growth. One (8%) patient maintained stable aneurysm size with a persistent type II endoleak, and 11 (85%) patients had aneurysm shrinkage. PASE to induce sac thrombosis after EVAR is an alternative for the treatment of endoleaks. Further study is required to define optimal patient selection, safety, long-term efficacy and potential cost-savings of this technique.

Regrown first rib in patients with recurrent thoracic outlet syndrome.

Congenital anomalies of the inferior vena cava (IVC), although rare, are a risk factor for lower limb deep venous thrombosis (DVT). A 19-year-old male presented with a left flank and groin pain caused by iliofemoral venous thrombosis. Vascular imaging by computed tomography (CT) scanning and venography demonstrated agenesis of the IVC. Catheter-directed thrombolysis via a popliteal vein was attempted but did not alter the patency of the common femoral vein outflow collaterals into the retroperitoneal azygous venous system. The patient was anticoagulated using systemic heparin infusion and clinical symptoms resolved within 5 days. He was transitioned to oral Coumadin anticoagulation, and follow-up venous duplex testing demonstrated no infrainguinal DVT and phasic venous flow with respiration in the femoral vein indicating patent collateral veins. Anomalies of the IVC are present in 0.3-0.5% of otherwise healthy individuals. Agenesis of the IVC has an incidence of 0.0005-1% in the general population but is found in almost 5% of patients <30 years of age with unprovoked lower limb DVT. In adults, IVC agenesis anomaly can cause diagnostic problems in the paravertebral area because of the tumor-like appearance of the azygous venous collaterals on noncontrast CT imaging. In young adults presenting with unprovoked lower limb DVT, the presence of an IVC anomaly should be considered and evaluated for by venous duplex testing and if necessary CT venography.

Interpretation of peripheral venous duplex testing

BACKGROUND Recurrent symptoms of thoracic outlet syndrome (TOS) after first rib resection have varying etiologies. Regrowth of a first rib is a rare event. Recurrent symptoms in the presence of a regrown rib strongly suggest a causal relationship. We report our experience with recurrent symptoms of TOS and regrown first ribs. METHODS We identified patients with recurrent TOS symptoms and regrown first ribs presented between 1995 and 2012. Details regarding their presentation, evaluation, and treatment were gathered. RESULTS Eight patients (6 women and 2 men) presenting with recurrent TOS symptoms and regrown first ribs underwent 10 decompression surgeries. Prior surgeries included supraclavicular first rib resection (5), transaxillary first rib resection (5), scalenectomy (5), cervical rib resection (1). The average period between initial surgery and reoperation was 4.7 years. Average age at current presentation was 40.8 years (range 29-52). All patients (8) represented with neurogenic symptoms and 1 patient with concomitant venous TOS symptoms. Presenting symptoms included pain (8), numbness and tingling (7), weakness (6), headache (2), and venous congestion (3). Initial treatment included physical therapy in all. Preoperative assessment included chest X-rays (8), magnetic resonance imaging (7), electrodiagnostic studies (8), venography (2), and anterior scalene muscle block (2). Surgical approach included transaxillary resection of the regrown first rib (10), neurolysis of brachial plexus (10), scalenectomy (5), and lysis of subclavian vein (1). After an average follow-up of 10.8 months, resolution of symptoms included 4 complete and 4 partial. CONCLUSIONS Regrowth of the first rib is a rare event. There is a concordance between a regrown rib and TOS symptoms. Patients presenting with recurrent TOS symptoms and a regrown first rib have a high probability of improvement with resection of the regrown rib.

Staged Hybrid Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm with Aortocaval Fistula

Venous duplex ultrasound and plethysmography are used to evaluate patients for suspected deep venous thrombosis (DVT) or venous insufficiency symptoms. Testing can provide clinicians with detailed information on location, extent, and severity of venous conditions before and after treatment. Duplex ultrasound can image the venous system from the vena cava to the peripheral veins, including veins of the calf musculature, and is the recommended technique to diagnose DVT. Accurate interpretation of venous testing requires an understanding of venous hemodynamics, including normal flow phasicity with cardiac and respiratory motion and the changes produced by acute DVT. Duplex scanning provides a roadmap of vein anatomy similar to contrast venography and essential hemodynamic information about the presence of proximal obstruction, vein valve function, and perforator vein reflux. Indications for testing include the diagnosis of acute/chronic DVT and evaluation of patients with venous insufficiency manifested as edema, varicose veins, or ambulatory venous hypertension. Venous plethysmography, an indirect physiologic test, can be used to estimate severity of obstructive or reflux venous pathophysiology and document improvement in venous hemodynamics after intervention. Using criteria based on ultrasound imaging and physiologic testing, venous conditions producing a swollen or painful limb can be accurately determined and aid in appropriate treatment selection.