Alexei S. Mlodinow

Surgical Duration and Risk of Venous Thromboembolism

IMPORTANCE There is a paucity of data assessing the effect of increased surgical duration on the incidence of venous thromboembolism (VTE). OBJECTIVE To examine the association between surgical duration and the incidence of VTE. DESIGN, SETTINGS, AND PARTICIPANTS Retrospective cohort of 1,432,855 patients undergoing surgery under general anesthesia at 315 US hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program from 2005 to 2011. EXPOSURE Duration of surgery. MAIN OUTCOMES AND MEASURES The rates of deep vein thrombosis (DVT), pulmonary embolism (PE), and VTE within 30 days of the index operation. Surgical duration was standardized across Current Procedural Terminology codes using a z score. Outcomes were compared across quintiles of the z score. Multiple logistic regression models were developed to examine the association while adjusting for patient demographics, clinical characteristics, and comorbidities. RESULTS The overall VTE rate was 0.96% (n = 13,809); the rates of DVT and PE were 0.71% (n = 10,198) and 0.33% (n = 4772), respectively. The association between surgical duration and VTE increased in a stepwise fashion. Compared with a procedure of average duration, patients undergoing the longest procedures experienced a 1.27-fold (95% CI, 1.21-1.34; adjusted risk difference [ARD], 0.23%) increase in the odds of developing a VTE; the shortest procedures demonstrated an odds ratio of 0.86 (95% CI, 0.83-0.88; ARD, -0.12%). The robustness of these results was substantiated with several sensitivity analyses attempting to minimize the effect of outliers, concurrent complications, procedural differences, and unmeasured confounding variables. CONCLUSIONS AND RELEVANCE Among patients undergoing surgery, an increase in surgical duration was directly associated with an increase in the risk for VTE. These findings may help inform preoperative and postoperative decision making related to surgery.

Predictors of readmission after breast reconstruction: a multi-institutional analysis of 5012 patients.

BackgroundRecent health care legislation institutes penalties for surgical readmissions secondary to complications. There is a paucity of evidence describing risk factors for readmission after breast reconstruction procedures. MethodsPatients undergoing breast reconstruction in 2011 were identified in the National Surgical Quality Improvement Program database. Patients were grouped as purely immediate implant/tissue-expander reconstructions or purely autologous reconstruction for analysis. Reconstructions involving multiple types of procedures were excluded due to difficulty with classification. Perioperative variables were analyzed using &khgr;2 and Student t test as appropriate. Multivariate regression modeling was used to identify risk factors for readmission. ResultsOf 5012 patients meeting inclusion criteria, 3960 and 1052 underwent implant/expander and autologous reconstructions, respectively. Implant/expander and autologous cohorts experienced similar readmission rates (4.34% vs 5.32%, respectively; P = 0.18). However, autologous reconstructions experienced a higher rate of overall complications than implant/expander reconstructions (19.96% vs 5.86%, respectively; P < 0.05), as well as higher rates of reoperation (9.7% vs 6.5%, respectively; P < 0.05). Common predictors of readmission for implant/expander and autologous cohorts included operative time, American Society of Anesthesiologist class 3 and 4, and superficial surgical site infection. Smoking, sepsis, deep wound infection, organ space infection, and wound disruption were predictive of readmission for implant/expander reconstruction only, whereas hypertension was predictive of readmission after autologous reconstruction only. ConclusionsThis is the first study of readmission rates after breast reconstruction. Knowledge of specific risk factors for readmission may improve patient outcomes, steer strategies for optimizing reconstructive outcomes, and minimize readmissions.

Comparison of Perioperative Outcomes in Outpatient and Inpatient Laparoscopic Hysterectomy

STUDY OBJECTIVE To compare 30-day postoperative outcomes in outpatient and inpatient laparoscopic hysterectomy procedures. DESIGN Retrospective observational study (Canadian Task Force classification II-2). SETTING More than 250 hospitals that participate in the American College of Surgeons National Surgical Quality Improvement Program. PATIENTS Women undergoing laparoscopic hysterectomy between 2006 and 2010. INTERVENTION Of 8846 patients, 3564 underwent treatment as outpatients, as defined by hospital billing. MEASUREMENTS AND MAIN RESULTS Overall morbidity was low in both cohorts; however, significantly fewer 30-day complications were observed in outpatients (4.5%) than inpatients (7.2%) (p < .001). Individual medical and wound complications were also rare and were less common in outpatients whenever a significant difference existed. After adjusting for demographic and operative variables, multivariate regression models found outpatients to be at significantly lower risk for overall perioperative morbidity (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.53-0.78). Outpatients were less likely to experience wound complications (OR, 0.63; 95% CI, 0.46-0.87) and were at lower risk of medical complications (adjusted OR, 0.61; 95% CI, 0.49-0.77) and deep vein thrombosis (adjusted odds ratio, 0.61; 95% CI, 0.47-0.80). Outpatient designation was not a significant predictor for repeat operation (p = .09). CONCLUSIONS Outpatient laparoscopic hysterectomy procedures are not associated with increased risk of 30-day postoperative complications.

Predictors of 30-day readmission after outpatient thyroidectomy: an analysis of the 2011 NSQIP data set.

PURPOSE With enhancements in patient safety and improvements in anesthesia administration, outpatient thyroidectomy is now frequently undertaken as an outpatient procedure, with several peer-reviewed reports of safe implementation totaling over 4500 procedures since 2006. However, robust statistical analyses of predictors for readmission are lacking. METHODS The 2011 NSQIP data set was queried to identify all patients undergoing thyroidectomy on an outpatient basis. Outcomes of interest included surgical and medical complications, reoperation, mortality, and readmission. Univariate and multivariate analyses were utilized to identify the predictors of these events. RESULTS In total 5121 patients were identified to have undergone an outpatient thyroidectomy in 2011. Overall 30-day morbidity was rare with only 47 patients (0.92%) experiencing any perioperative morbidity. One hundred eleven (2.17%) patients were readmitted within 30 days of the operation. A history of COPD was the only preoperative comorbid medical condition that significantly increased a patients risk for readmission (OR 3.73 95% CI 1.57-8.85, p=0.003). Patients with a surgical complication were more than 7 times as likely to be readmitted (OR 2.08-25.28, p=0.002), and those with a medical complication were over 19 times as likely to be readmitted (OR 7.32-50.78, p<0.001). CONCLUSIONS Readmission after outpatient thyroidectomy is infrequent, and compares well with other outpatient procedures. The main identified risks include preoperative COPD and any of the generic postoperative complications tracked in NSQIP. As procedures continue to transition into outpatient settings and financial penalties associated with readmission become a reality, these findings will serve to optimize outpatient surgery utilization.

Intraoperative transfusion of packed red blood cells in microvascular free tissue transfer patients: assessment of 30-day morbidity using the NSQIP dataset.

Although often a life-saving therapeutic maneuver, there is minimal data available that details the effects of intraoperative packed red blood cell transfusion (IOT) after microvascular free tissue transfer. The National Surgical Quality Improvement Program database was queried to identify all patients who underwent microvascular free tissue transfer between 2006 and 2010. Multivariate logistic regression models were used to determine the association between intraoperative transfusion and outcomes. Upon bivariate and multivariate analyses, IOT was significantly associated with higher rates of overall complications (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.12-3.63), medical complications (OR, 3.35; 95% CI, 1.75-6.42), postoperative transfusion (OR, 6.02; 95% CI, 2.02-17.97), and reoperation (OR, 2.24; 95% CI, 1.24-4.04). IOT was not associated with either surgical complications or free flap loss. IOT significantly increases risk for adverse overall and medical complications. However, IOT was not associated with surgical complications or free flap loss. Transfusion practices in the operating room should be reevaluated to improve overall outcomes.

Anemia is not a predictor of free flap failure: A review of NSQIP data

Thrombosis is a common cause of flap failure in microvascular tissue transfer, which questions the effects of anemia on this outcome. This article seeks to contribute a large, multi‐institutional data analysis to this debate.

Risk factors for mastectomy flap necrosis following immediate tissue expander breast reconstruction

Abstract Tissue expander placement is a mainstay of reconstructive surgery in the post-mastectomy patient. Necrosis of the native breast tissue is one of the most significant concerns in their post-operative care. The goal of this study is to elucidate factors that confer risk of this outcome. Chart review was conducted for a consecutive series of immediate tissue expander reconstructions by the two senior authors. Data was collected for several preoperative and intraoperative variables, as well as the outcome of mastectomy flap necrosis. Of the 1566 breasts that were examined, 135 (8.6%) experienced flap necrosis. The cohorts with and without flap necrosis were well matched. Those with the outcome of interest had significantly higher rates of switching to an autologous method of reconstruction (31.9% vs 6.2%, p < 0.001). Regression analysis revealed smoking status, increased age, tumescent mastectomy technique, and high (>66.67%) intraoperative tissue expander fill to confer increased risk of mastectomy flap necrosis. While smoking and older age are well-supported by the literature, tumescent technique and tissue expander fill are more novel points of discussion, which may serve as proxies for other issues. Awareness of these risk factors and their interplay will aid in clinical judgement and postoperative care of these patients.

Individualized Risk of Surgical Complications: An Application of the Breast Reconstruction Risk Assessment Score

Background: Risk discussion is a central tenet of the dialogue between surgeon and patient. Risk calculators have recently offered a new way to integrate evidence-based practice into the discussion of individualized patient risk and expectation management. Focusing on the comprehensive Tracking Operations and Outcomes for Plastic Surgeons (TOPS) database, we endeavored to add plastic surgical outcomes to the previously developed Breast Reconstruction Risk Assessment (BRA) score. Methods: The TOPS database from 2008 to 2011 was queried for patients undergoing breast reconstruction. Regression models were constructed for the following complications: seroma, dehiscence, surgical site infection (SSI), explantation, flap failure, reoperation, and overall complications. Results: Of 11,992 cases, 4439 met inclusion criteria. Overall complication rate was 15.9%, with rates of 3.4% for seroma, 4.0% for SSI, 6.1% for dehiscence, 3.7% for explantation, 7.0% for flap loss, and 6.4% for reoperation. Individualized risk models were developed with acceptable goodness of fit, accuracy, and internal validity. Distribution of overall complication risk was broad and asymmetric, meaning that the average risk was often a poor estimate of the risk for any given patient. These models were added to the previously developed open-access version of the risk calculator, available at http://www.BRAscore.org. Conclusions: Population-based measures of risk may not accurately reflect risk for many individual patients. In this era of increasing emphasis on evidence-based medicine, we have developed a breast reconstruction risk assessment calculator from the robust TOPS database. The BRA Score tool can aid in individualizing—and quantifying—risk to better inform surgical decision making and better manage patient expectations.

Increased anaesthesia duration increases venous thromboembolism risk in plastic surgery: A 6-year analysis of over 19,000 cases using the NSQIP dataset

Abstract Background: Venous thromboembolism (VTE) is a significant cause of morbidity and mortality, particularly in the postoperative setting. Various risk stratification schema exist in the plastic surgery literature, but do not take into account variations in procedure length. The putative risk of VTE conferred by increased length of time under anaesthesia has never been rigorously explored. Aim: The goal of this study is to assess this relationship and to benchmark VTE rates in plastic surgery. Methods: A large, multi-institutional quality-improvement database was queried for plastic and reconstructive surgery procedures performed under general anaesthesia between 2005–2011. In total, 19,276 cases were abstracted from the database. Z-scores were calculated based on procedure-specific mean surgical durations, to assess each case’s length in comparison to the mean for that procedure. A total of 70 patients (0.36%) experienced a post-operative VTE. Patients with and without post-operative VTE were compared with respect to a variety of demographics, comorbidities, and intraoperative characteristics. Potential confounders for VTE were included in a regression model, along with the Z-scores. Results: VTE occurred in both cosmetic and reconstructive procedures. Longer surgery time, relative to procedural means, was associated with increased VTE rates. Further, regression analysis showed increase in Z-score to be an independent risk factor for post-operative VTE (Odds Ratio of 1.772 per unit, p-value < 0.001). Subgroup analyses corroborated these findings. Conclusions: This study validates the long-held view that increased surgical duration confers risk of VTE, as well as benchmarks VTE rates in plastic surgery procedures. While this in itself does not suggest an intervention, surgical time under general anaesthesia would be a useful addition to existing risk models in plastic surgery.

The use of patient registries in breast surgery: a comparison of the tracking operations and outcomes for plastic surgeons and national surgical quality improvement program data sets.

BackgroundThe National Surgical Quality Improvement Program (NSQIP) and the Tracking Operations and Outcomes for Plastic Surgeons (TOPS) registries gather outcomes for plastic surgery procedures. The NSQIP collects hospital data using trained nurses, and the TOPS relies on self-reported data. We endeavored to compare the TOPS and NSQIP data sets with respect to cohort characteristics and outcomes to better understand the strengths and weakness of each registry as afforded by their distinct data collection methods. Study DesignThe 2008 to 2011 TOPS and NSQIP databases were queried for breast reductions and breast reconstructions. Propensity score matching identified similar cohorts from the TOPS and NSQIP databases. Shared 30-day surgical and medical complications rates were compared across matched cohorts. ResultsThe TOPS captured a significantly greater number of wound dehiscence occurrences (4.77%–5.47% vs 0.69%–1.17%, all P < 0.001), as well as more reconstructive failures after prosthetic reconstruction (2.82% vs 0.26%, P < 0.001). Medical complications were greater in NSQIP (P < 0.05). Other complication rates did not differ across any procedure (all P > 0.05). ConclusionsThe TOPS and NSQIP capture significantly different patient populations, with TOPS’ self-reported data allowing for the inclusion of private practices. This self-reporting limits TOPS’ ability to identify medical complications; surgical complications and readmissions, however, were not underreported. Many surgical complications are captured by TOPS at a higher rate due to its broader definitions, and others are not captured by NSQIP at all. The TOPS and NSQIP provide complementary information with different strengths and weakness that together can guide evidence-based decision making in plastic surgery.