Daniel Nelson

Analysis of Obesity-Related Outcomes and Bariatric Failure Rates With the Duodenal Switch vs Gastric Bypass for Morbid Obesity

OBJECTIVE To compare the outcomes of a large cohort undergoing biliopancreatic diversion/duodenal switch (DS) vs gastric bypass (GB). DESIGN Retrospective review of the Bariatric Outcomes Longitudinal Database from 2007 to 2010. All inpatient and outpatient follow-up data were analyzed. SETTING Multicenter database. PATIENTS Patients undergoing primary DS were compared with a concurrent cohort undergoing GB. MAIN OUTCOME MEASURES The main outcome measures were (1) weight loss; (2) control of comorbidities including diabetes mellitus, hypertension, and sleep apnea; and (3) failure to achieve at least 50% excess body weight loss. RESULTS One thousand five hundred forty-five patients underwent DS and 77 406 underwent GB, with a mean preoperative body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 52 and 48, respectively (P < .01). The DS was associated with longer operative times, greater blood loss, and longer lengths of hospital stay (all P < .05). Early reoperation rates were higher in the DS group (3.3% vs 1.5%). Percentage of change in BMI was significantly greater in the DS group at all follow-up intervals (P < .05). Subgroup analysis of the superobese population (BMI >50) revealed significantly greater percentage of excess body weight loss in the DS group at 2 years (79% vs 67%; P < .01). Comorbidity control of diabetes, hypertension, and sleep apnea were all superior with the DS (all P < .05). The risk of weight loss failure was significantly reduced with DS vs GB for all patients, with a greater reduction in the BMI more than 50 subgroup. CONCLUSIONS The DS is a less commonly used bariatric operation, with higher early risks compared with GB. However, the DS achieved better weight and comorbidity control, with even more pronounced benefits among the superobese.

Tranexamic acid administration to pediatric trauma patients in a combat setting: the pediatric trauma and tranexamic acid study (PED-TRAX).

BACKGROUND Early administration of tranexamic acid (TXA) has been associated with a reduction in mortality and blood product requirements in severely injured adults. It has also shown significantly reduced blood loss and transfusion requirements in major elective pediatric surgery, but no published data have examined the use of TXA in pediatric trauma. METHODS This is a retrospective review of all pediatric trauma admissions to the North Atlantic Treaty Organization Role 3 hospital, Camp Bastion, Afghanistan, from 2008 to 2012. Univariate and logistic regression analyses of all patients and select subgroups were performed to identify factors associated with TXA use and mortality. Standard adult dosing of TXA was used in all patients. RESULTS There were 766 injured patients 18 years or younger (mean [SD] age, 11 [5] years; 88% male; 73% penetrating injury; mean [SD], Injury Severity Score [ISS], 10 [9]; mean [SD] Glasgow Coma Scale [GCS] score, 12 [4]). Of these patients, 35% required transfusion in the first 24 hours, 10% received massive transfusion, and 76% required surgery. Overall mortality was 9%. Of the 766 patients, 66 (9%) received TXA. The only independent predictors of TXA use were severe abdominal or extremity injury (Abbreviated Injury Scale [AIS] score ≥ 3) and a base deficit of greater than 5 (all p < 0.05). Patients who received TXA had greater injury severity, hypotension, acidosis, and coagulopathy versus the patients in the no-TXA group. After correction for demographics, injury type and severity, vitals, and laboratory parameters, TXA use was independently associated with decreased mortality among all patients (odds ratio, 0.3; p = 0.03) and showed similar trends for subgroups of severely injured (ISS > 15) and transfused patients. There was no significant difference in thromboembolic complications or other cardiovascular events. Propensity analysis confirmed the TXA-associated survival advantage and suggested significant improvements in discharge neurologic status as well as decreased ventilator dependence. CONCLUSION TXA was used in approximately 10% of pediatric combat trauma patients, typically in the setting of severe abdominal or extremity trauma and metabolic acidosis. TXA administration was independently associated with decreased mortality. There were no adverse safety- or medication-related complications identified. LEVEL OF EVIDENCE Therapeutic study, level IV.

Current Approaches and Challenges for Monitoring Treatment Response in Colon and Rectal Cancer

Introduction: With the advent of multidisciplinary and multimodality approaches to the management of colorectal cancer patients, there is an increasing need to define how we monitor response to novel therapies in these patients. Several factors ranging from the type of therapy used to the intrinsic biology of the tumor play a role in tumor response. All of these can aid in determining the ideal course of treatment, and may fluctuate over time, pending down-staging or progression of disease. Therefore, monitoring how disease responds to therapy requires standardization in order to ultimately optimize patient outcomes. Unfortunately, how best to do this remains a topic of debate among oncologists, pathologists, and colorectal surgeons. There may not be one single best approach. The goal of the present article is to shed some light on current approaches and challenges to monitoring treatment response for colorectal cancer. Methods: A literature search was conducted utilizing PubMed and the OVID library. Key-word combinations included colorectal cancer metastases, neoadjuvant therapy, rectal cancer, imaging modalities, CEA, down-staging, tumor response, and biomarkers. Directed searches of the embedded references from the primary articles were also performed in selected circumstances. Results: Pathologic examination of the post-treatment surgical specimen is the gold standard for monitoring response to therapy. Endoscopy is useful for evaluating local recurrence, but not in assessing tumor response outside of the limited information gained by direct examination of intra-lumenal lesions. Imaging is used to monitor tumors throughout the body for response, with CT, PET, and MRI employed in different circumstances. Overall, each has been validated in the monitoring of patients with colorectal cancer and residual tumors. Conclusion: Although there is no imaging or serum test to precisely correlate with a tumors response to chemo- or radiation therapy, these modalities, when used in combination, can aid in allowing clinicians to adjust medical therapy, pursue operative intervention, or (in select cases) identify complete responders. Improvements are needed, however, as advances across multiple modalities could allow appropriate selection of patients for a close surveillance regimen in the absence of operative intervention.

Thromboembolic Complications and Prophylaxis Patterns in Colorectal Surgery.

IMPORTANCE Venous thromboembolism (VTE) is an important complication of colorectal surgery, but its incidence is unclear in the era of VTE prophylaxis. OBJECTIVE To describe the incidence of and risk factors associated with thromboembolic complications and contemporary VTE prophylaxis patterns following colorectal surgery. DESIGN, SETTING, AND PARTICIPANTS Prospective data from the Washington State Surgical Care and Outcomes Assessment Program (SCOAP) linked to a statewide hospital discharge database. At 52 Washington State SCOAP hospitals, participants included consecutive patients undergoing colorectal surgery between January 1, 2006, and December 31, 2011. MAIN OUTCOMES AND MEASURES Venous thromboembolism complications in-hospital and up to 90 days after surgery. RESULTS Among 16,120 patients (mean age, 61.4 years; 54.5% female), the use of perioperative and in-hospital VTE chemoprophylaxis increased significantly from 31.6% to 86.4% and from 59.6% to 91.4%, respectively, by 2011 (P < .001 for trend for both). Overall, 10.6% (1399 of 13,230) were discharged on a chemoprophylaxis regimen. The incidence of VTE was 2.2% (360 of 16,120). Patients undergoing abdominal operations had higher rates of 90-day VTE compared with patients having pelvic operations (2.5% [246 of 9702] vs 1.8% [114 of 6413], P = .001). Those having an operation for cancer had a similar incidence of 90-day VTE compared with those having an operation for nonmalignant processes (2.1% [128 of 6213] vs 2.3% [232 of 9902], P = .24). On adjusted analysis, older age, nonelective surgery, history of VTE, and operations for inflammatory disease were associated with increased risk of 90-day VTE (P < .05 for all). There was no significant decrease in VTE over time. CONCLUSIONS AND RELEVANCE Venous thromboembolism rates are low and largely unchanged despite increases in perioperative and postoperative prophylaxis. These data should be considered in developing future guidelines.

The effects of tranexamic acid and prothrombin complex concentrate on the coagulopathy of trauma: An in vitro analysis of the impact of severe acidosis

BACKGROUND Bleeding is the most frequent cause of preventable death after severe injury. Our purposes were to study the efficacy of tranexamic acid (TXA) and prothrombin complex concentrate (PCC) on a traumatic coagulopathy with a severe native metabolic acidosis and compare the efficacy of PCC versus fresh frozen plasma (FFP) to reverse a dilutional coagulopathy. METHODS In vitro effects of TXA and PCC were assessed with standard laboratory analysis (prothrombin time [PT]/international normalized ratio [INR]) and rotational thromboelastometry in a porcine hemorrhage with ischemia-reperfusion (H/I) model. FFP was used in comparison with PCC. In vitro doses were calculated to be the equivalent of 1-g TXA, 100-mg tissue plasminogen activator, 45-IU/kg PCC, and 4-U FFP. Agents were tested at baseline and then with severe metabolic acidosis after 6 hours of resuscitation. RESULTS Thirty-one swine were studied. Baseline hematocrit was 24%, pH was 7.56, INR was 1.0, and lactate level was 1.47. Six hours after H/I, the hematocrit was 15.9%, pH was 7.1, INR was 1.7, and lactate level was 10.26. Rotational thromboelastometry revealed that maximum clot firmness at baseline was 71.71 mm and decreased to 0.29 mm with tissue plasminogen activator, representing severe fibrinolysis. Following TXA dosing, the maximum clot firmness was immediately corrected to 69.06 mm. There was no difference (p = 0.48) between TXA function at baseline pH (mean, 7.56) or acidotic pH (mean, 7.11). The mean baseline PT was 13 ± 0.49 seconds (INR, 1). After H/I and resuscitation, the mean PT was 23.03 seconds (INR, 2.1). PCC reduced the PT to 20 (INR, 1.75; p = 0.001) and FFP to 17.44 (INR, 1.47; p = 0.001). CONCLUSION Both TXA and PCC seem to function well in reversing a traumatic coagulopathy in vitro, and TXA seems to have no loss of function in a severe metabolic acidosis. Further investigations are warranted.

Examining the accuracy and clinical usefulness of intraoperative frozen section analysis in the management of pancreatic lesions

BACKGROUND Intraoperative frozen section analysis is often performed in the surgical management of pancreatic lesions. This test is used to obtain histologic diagnosis, to assess resectability because of unanticipated locoregional spread, and to ensure negative margins after resection. We sought to define the accuracy and clinical usefulness of intraoperative frozen section analysis in patients with pancreatic lesions and to determine the impact on long-term outcomes. METHODS A retrospective database review was performed for all patients who underwent pancreatic resection at our institution from 2002 to 2011. Patient demographics, indications for frozen section analysis, final pathology, and long-term outcomes were analyzed. Five-year survival was compared using the Kaplan-Meier method. RESULTS Sixty-eight patients were identified (mean age 65 ± 14 years, 52% female). Malignancy was identified on final pathology in 38 (56%) patients. Intraoperative frozen section analysis was performed in 59 (87%) patients. Frozen section analysis was performed for histologic diagnosis in 6 (10%) cases, to determine resectability in 15 (25%) cases, and to evaluate margin status in 58 (98%) cases. Frozen section analysis for histologic diagnosis was associated with a sensitivity of 80%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 50% with an overall accuracy of 83%. Frozen section analysis for the determination of resectability was associated with a sensitivity of 38%, specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 58% with an overall accuracy of 66%. Intraoperative frozen section analysis for the determination of the final margin status was associated with a sensitivity of 33%, specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 97% with an overall accuracy of 97%. There were no false-positive results on frozen section analysis. Errors on frozen section analysis interpretation did not negatively impact survival outcomes (mean survival = 2.2 years in those with concordant frozen section analysis vs 1.7 years in those with discordant frozen section analysis, P = .69). CONCLUSIONS Although intraoperative frozen section analysis is helpful for ensuring negative final margins, its usefulness for obtaining histologic diagnosis and determining resectability is limited by low negative predictive potential. These results highlight the importance of preoperative staging and intraoperative surgical judgment for questionable resectable disease.

Examining the relevance of the physician's clinical assessment and the reliance on computed tomography in diagnosing acute appendicitis

BACKGROUND The aim of this study was to examine the relevance of clinical assessment in diagnosing appendicitis in the current medical environment, in which routine use of computed tomography (CT) has become the norm. METHODS A retrospective review was conducted, analyzing patient demographics, Alvarado clinical assessment scoring, and radiologic and pathologic results. RESULTS A total of 664 patients were identified. Higher Alvarado scores were significantly associated with pathologically confirmed appendicitis (low, 87%; moderate, 92%; high, 96%; P = .05). As clinical assessment scores increased, use of CT decreased significantly (low, 97%; moderate, 85%; high, 79%; P = .01). The negative appendectomy rate for patients with clinical assessments consistent with appendicitis was 4%, compared with 3% associated with CT. Regardless of assessment scores, 82% of the cohort underwent CT. From a random sample of 100 charts, 87% of initial emergency department plans stratified disposition on the basis of the results of CT. CONCLUSIONS Although physical examination remains crucial, CT has become the primary modality dictating care of patients with presumed appendicitis.

Evaluation of the risk of noncontiguous fractures of the spine in blunt trauma.

BACKGROUND There is significant debate over the risk of additional noncontiguous (NC) fractures among blunt trauma patients with an identified spinal column injury, often prompting routine full-spine imaging. We sought to determine the incidence of NC spinal fractures and the relationship between injury pattern and mechanism. METHODS A review of all adult blunt trauma patients from the 2010 National Trauma Data Bank with a spine fracture. Patient demographics, mechanism of injury, and frequencies of all combinations of spinal fractures were analyzed. RESULTS Among 654,052 blunt trauma patients, 83,338 (13%) had a diagnosed spine fracture. The mean (SD) Injury Severity Score (ISS) was 15 (11). Of these, 7% (5,496) sustained spinal cord injury, and 17% (14,413) underwent spinal surgery during their index hospitalization. Among those with spinal column fractures, the overall incidence of NC fractures was 19% and was associated with severe truncal injuries, primarily involving the chest. The relative incidences of cervical, thoracic, and lumbar fractures were 41% (34,480), 37% (30,383), and 43% (35,778), respectively. Rates of NC fractures of the spine included 9% cervicothoracic (7,406), 4% cervicolumbar (3,415), and 10% thoracolumbar (7,929). The slight majority (57%) of patients with spinal fractures sustained high-velocity trauma compared with 43% associated with low-velocity trauma. However, NC fractures of the spine were strongly associated with high-velocity trauma. CONCLUSION Spine fractures are relatively common with blunt trauma, and approximately 20% of patients with a spinal column fracture will have an NC fracture. NC fractures were associated with other severe injuries and should be mainly suspected and investigated in high-velocity mechanisms. LEVEL OF EVIDENCE Prognostic study, level III; therapeutic study, level IV.

Early results after introduction of biliopancreatic diversion/duodenal switch at a military bariatric center

BACKGROUND Biliopancreatic diversion with duodenal switch (BPD/DS) is one of the most effective procedures in terms of weight loss and durability. It is also one of the most complex and highest risk bariatric procedures. The authors report their initial experience with BPD/DS. METHODS A retrospective review of all patients undergoing BPD/DS was performed, including a descriptive analysis of demographics, operative data, complications, and outcomes. Results were also compared with those among a group of 100 patients undergoing laparoscopic gastric bypass (LGB). RESULTS Forty-three patients were identified. Mean preoperative body mass index was 52 kg/m(2), and 56% of patients had body mass indexes > 50 kg/m(2). Twenty (47%) were attempted laparoscopically, with 5 (25%) requiring conversion to open approach. Overall mean operative time was 269 minutes, with no significant difference between laparoscopic (256 minutes) and open (280 minutes). No major intraoperative complications occurred. Major postoperative complications included 4 gastric sleeve leaks, 2 small bowel obstructions, 1 intra-abdominal hemorrhage, and 1 duodenal stump leak. There was 1 death. Mean percentage excess body weight loss was 85% at 1 year. No patients developed severe malabsorptive symptoms or evidence of protein malnutrition. BPD/DS was associated with longer operative times and higher complication rates (P < .05 for both) compared with LGB but had significantly greater weight loss at 1 year (P < .05). CONCLUSION BPD/DS is a complex procedure associated with increased operative times, increased risk for conversion from laparoscopic to open approach, and higher postoperative complication rates. However, it results in significantly greater weight loss than LGB without major adverse nutritional impact.

The impact of Model for End-Stage Liver Disease-Na in predicting morbidity and mortality following elective colon cancer surgery irrespective of underlying liver disease.

BACKGROUND The Model for End-Stage Liver Disease Sodium Model (MELD-Na) is a validated scoring system that uses bilirubin, international normalized ratio, serum creatinine, and sodium to predict mortality in cirrhotic patients awaiting liver transplantation. The aim of this study was to identify the utility of MELD-Na to predict patient outcomes, with and without liver disease, after elective colon cancer surgery. METHODS A review of the American College of Surgeons National Surgical Quality Improvement Program database (2005 to 2010) was conducted to calculate risk-adjusted 30-day outcomes using regression modeling. RESULTS A total of 10,842 patients (mean age, 68 years; 51% women) were included. MELD-Na scores were higher in men (10.2 vs 9.1, P < .001) and in open procedures (9.9 vs 9.1, P < .001). The overall complication and mortality rates were 26.3% and 3.3%, respectively. Incremental increases in MELD-Na score correlated with a 1.2% increase in mortality and a 1.1% increase in complications. On multivariate analysis, complications increased with MELD-Na score (odds ratio [OR], 1.05 per 1 point increase; 95% confidence interval [CI], 1.038 to 1.066). MELD-Na score was also associated with increased mortality (OR, 1.13; 95% CI, 1.1 to 1.16), along with ascites (OR, 5.7; 95% CI, 3.7 to 8.8) and corticosteroids (OR, 2.1; 95% CI, 1.3 to 3.3). CONCLUSIONS Elevated preoperative MELD-Na score is significantly associated with worse outcomes after elective resection for colon cancer.