Body mass index as a correlate of postoperative complications and resource utilization

Postoperative Staphylococcus aureus Infections in Patients With and Without Preoperative Colonization

Importance

Staphylococcus aureus surgical site infections (SSIs) and bloodstream infections (BSIs) are important complications of surgical procedures for which prevention remains suboptimal. Contemporary data on the incidence of and etiologic factors for these infections are needed to support the development of improved preventive strategies.

Objectives

To assess the occurrence of postoperative S aureus SSIs and BSIs and quantify its association with patient-related and contextual factors.

Design, Setting, and Participants

This multicenter cohort study assessed surgical patients at 33 hospitals in 10 European countries who were recruited between December 16, 2016, and September 30, 2019 (follow-up through December 30, 2019). Enrolled patients were actively followed up for up to 90 days after surgery to assess the occurrence of S aureus SSIs and BSIs. Data analysis was performed between November 20, 2020, and April 21, 2022. All patients were 18 years or older and had undergone 11 different types of surgical procedures. They were screened for S aureus colonization in the nose, throat, and perineum within 30 days before surgery (source population). Both S aureus carriers and noncarriers were subsequently enrolled in a 2:1 ratio.

Exposure

Preoperative S aureus colonization.

Main Outcomes and Measures

The main outcome was cumulative incidence of S aureus SSIs and BSIs estimated for the source population, using weighted incidence calculation. The independent association of candidate variables was estimated using multivariable Cox proportional hazards regression models.

Results

In total, 5004 patients (median [IQR] age, 66 [56-72] years; 2510 [50.2%] female) were enrolled in the study cohort; 3369 (67.3%) were S aureus carriers. One hundred patients developed S aureus SSIs or BSIs within 90 days after surgery. The weighted cumulative incidence of S aureus SSIs or BSIs was 2.55% (95% CI, 2.05%-3.12%) for carriers and 0.52% (95% CI, 0.22%-0.91%) for noncarriers. Preoperative S aureus colonization (adjusted hazard ratio [AHR], 4.38; 95% CI, 2.19-8.76), having nonremovable implants (AHR, 2.00; 95% CI, 1.15-3.49), undergoing mastectomy (AHR, 5.13; 95% CI, 1.87-14.08) or neurosurgery (AHR, 2.47; 95% CI, 1.09-5.61) (compared with orthopedic surgery), and body mass index (AHR, 1.05; 95% CI, 1.01-1.08 per unit increase) were independently associated with S aureus SSIs and BSIs.

Conclusions and Relevance

In this cohort study of surgical patients, S aureus carriage was associated with an increased risk of developing S aureus SSIs and BSIs. Both modifiable and nonmodifiable etiologic factors were associated with this risk and should be addressed in those at increased S aureus SSI and BSI risk.

Textbook outcome as a composite measure of quality in hepaticopancreatic surgery

BACKGROUND

Textbook outcome (TO) is a valuable metric to assess postoperative outcomes. The aim of this study was to assess TO in patients undergoing hepatopancreatic surgery.

METHODS

This was a retrospective cohort NSQIP study from 2015 to 2018. TOs are defined as no complication or mortality and length of stay within the 75th percentile.

RESULTS

This study included 44 235 patients. Of those patients, 61% underwent pancreatic surgery (PS) and 39% hepatic surgery (HS). The most common surgical procedure was pancreaticoduodenectomy (16 464), followed by partial hepatectomy (11 817), distal pancreatectomy (8292), hemihepatectomy (4247), hepatic trisegmentectomy (1366) and total pancreatectomy (706). TO was more common for HS than PS, 47% versus 40%, p < .001. TO was more common for younger (0-65, OR: 1.60; CI: 1.30-1.96, p < .001), female (OR: 1.23; CI: 1.17-1.29, p < .001), white (OR: 1.10; CI: 1.01-1.19, p = .022), and lower ASA class (OR: 2.11; CI: 1.54-2.90, p < .001) patients. For patients undergoing HS TO was more common after partial lobectomy than trisegmentectomy and lobectomy (OR: 1.36; CI: 1.18-1.57, p < .001). For those undergoing PS, there was a lower likelihood of TO for those who are obese/morbidly obese compared to normal-weight patients (OR: 0.73; CI: 0.67-0.79, p < .001). Unlike HS, TO for patients undergoing PS was not associated with the type of surgical procedure.

CONCLUSIONS

TO is a composite that can be applied to a national data set to analyze outcome quality. In HS, more complex surgical procedures are associated with a decreased likelihood of TO. In PS, TO are similar regardless of the procedure but less common in obese or morbidly obese patients.

Epidemiology of Obese Patients Undergoing Revision Total Knee Arthroplasty: Understanding Demographics, Comorbidities, and Propensity Weighted Analysis of Inpatient Outcomes

INTRODUCTION

Obesity is a public health epidemic that is projected to grow in coming years. Observational data on the epidemiologic profile and immediate postoperative outcomes of obesity and morbid obesity after revision total knee arthroplasty (rTKA) are limited.

METHODS

Discharge data from the National Inpatient Sample was used to identify patients who underwent rTKA from 2006 to 2015. Patients were stratified into morbidly obese, obese, and not obese control cohorts. An analysis was performed to compare etiology of revision, demographic and medical comorbidity profiles, and immediate in-hospital economic and complication outcomes after rTKA.

RESULTS

An estimated 605,603 rTKAs were included in this analysis. Morbidly obese and obese patients were at significantly higher risk for any complication than not obese patients. Patients with obesity were associated with an increased risk of postoperative anemia but a lower risk of peripheral vascular disease and gastrointestinal, and hematoma/seroma complications compared with not obese patients. Patients with morbid obesity were associated with an increased risk of any, hematoma/seroma, wound dehiscence, postoperative infection, pulmonary embolism, and postoperative anemia complications and a lower risk of gastrointestinal complications when compared with not obese patients. Morbidly obese patients had a significantly longer length of stay than both obese and not obese patients, while no significant difference in length of stay was observed between obese and not obese patients.

DISCUSSION

Morbidly obese patients are at higher odds for worse postoperative medical and economic outcomes compared with those with obesity after rTKA. As the number of patients with obesity and morbid obesity continues to rise, these risk factors should be considered in preoperative discussions and perioperative protocol optimization.

A Prospective Review of Preoperative Nutritional Status and Its Influence on the Outcome of Abdominal Surgery

Aim

To assess the incidence of malnutrition in a surgical gastroenterology unit and analyze its impact on postoperative complication rates.

Method

Data were prospectively accrued from patients admitted for emergency or elective surgery to the gastrointestinal surgery unit at Jaslok Hospital between May 2013 and May 2014. The nutritional status was preoperatively assessed by using anthropometric parameters like body mass index (BMI), midarm circumference (MAC), and tissue skinfold thickness (TSFT). In addition, a subjective global assessment scale (SGA), serum albumin, and absolute lymphocyte count (ALC) were used. Patients with BMI <18.5, MAC <24 cm in males and <22 cm in females, and TSFT <10 mm were considered malnourished. Patients with serum albumin between 3 and 3.5 g/dl were considered mild, 2.4-2.9 g/dl was moderate, and <2.4 g/dl were severely malnourished. Patients with ALC between 1200 and 2000/cm were labelled mild, between 800 and 1199/cm were moderate, and <800/cm were severely malnourished. As per SGA, well-nourished had less than 5% weight loss or if more than 5%, with recent gain and improved appetite, mild/moderately malnourished had 5% to 10% weight loss with no gain, mild subcutaneous fat loss, and those severely malnourished had more than 10% weight loss, severe subcutaneous fat loss, and muscle wasting. Postoperative complications were graded as per the Clavien-Dindo classification. Patients with grades 1 and 2 complications were labelled as minor and the rest as major.

Result

Men in the age group of 40-60 years comprised the majority of the study population. The most frequent reason for admission was cholelithiasis. The overall incidence of malnutrition was 22.16%. Out of the 96 patients who had complications, 45 had minor and 41 had significant complications. Amongst the well-nourished, the incidence of complications was 26.62% of which the majority were minor complications. Severely malnourished patients had a high complication rate (63.38%); 32% out of the 63.38% developed significant complications. The majority of the patients suffering from severe malnutrition belonged to the sub-group with chronic pancreatitis and carcinoma of the pancreas. According to the chi-square analysis of the data, ALC, serum albumin, and SGA correlate with the postoperative complication rate with a p-value <0.05 as significant. On the contrary, BMI, MAC, and TSFT did not correlate with postoperative complications.

Conclusion

Preoperative malnutrition is common among patients undergoing abdominal surgeries in the urban private health care sector. Although there have been studies that have analyzed the incidence of malnutrition in patients undergoing oncological surgeries, there is limited literature on malnutrition among patients subjected to gastrointestinal surgeries. We conclude that simple bedside nutritional assessment tools like serum albumin, absolute lymphocyte count, and SGA can accurately identify malnourished patients preoperatively and are good predictors of postoperative complications. Hence, it is imperative to assess and attempt to improve the nutritional status of the patients preoperatively.

The Flipped Operating Room: Establishing Best Practices in Surgical Education Using Resident-Initiated, Inquiry-Based Preoperative Briefing: Resident-Initiated Preoperative Briefing

OBJECTIVE

We performed a pilot study of a resident-initiated, inquiry-based preoperative briefing (R-PROB) to determine the feasibility and potential impact on the educational experience.

DESIGN

A prospective, qualitative pilot study was performed in a general surgery residency program. The R-PROB included pre-operative emails to faculty with case summaries, learning goals, and questions. Faculty responded by email, phone, or in-person. Semi-structured interviews were completed before and after R-PROB implementation. Interviews were transcribed, coded, and analyzed through collaboration with a mixed-methods laboratory.

SETTING

An urban, university-based general surgery residency PARTICIPANTS: Ten attendings from three university affiliated hospitals based on frequency of resident interaction, variation in experience and case types were selected. Thirteen residents that worked closely with the selected attendings, ranging from Clinical Year 1-5, were then recruited to participate.

RESULTS

The R-PROB was viewed overall positively and felt to be easily incorporated into the curriculum. The R-PROB significantly improved attending perception of resident preparedness. Junior residents (CY1-3) affirmed that R-PROB very strongly improved case preparation. The preoperative exchange was valued by both participants as improving communication frequency, transparency, and quality. The majority of attendings stated that the R-PROB enabled tailored teaching to each resident's level both preoperatively and in the operating room. Residents affirmed attending teaching to be more targeted towards their goals and objectives after the R-PROB. Challenges included late case assignments and minor time limitations.

CONCLUSIONS

A resident-initiated, inquiry-based preoperative briefing intervention is feasible and overall positively perceived by both participants. The briefings had a positive impact on resident preparedness, bi-directional communication, and permitted focused attending teaching.

Is Obesity Associated with Higher Complication Rates in Total Hip Arthroplasty for High-Riding Dysplastic Hips?

OBJECTIVE

Developmental dysplasia of the hip (DDH) is a disabling pathology leading to hip problems, such as painful arthritic hip, unstable hip, etc. Total hip arthroplasty (THA) is an effective treatment modality for this condition. Obesity has been shown to be associated with increased rates of complications following orthopaedic surgeries (Journal of Arthroplasty 20:46-50). The hypothesis of this study was that patients with a body mass index (BMI) greater than 30 (obese), who undergo total hip arthroplasty for dysplastic hip, are associated with longer operative and anaesthetic times, longer hospital stays and higher re-admission rates within 30 days.

METHODS

All the cases of total hip arthroplasty in patients with high-riding dysplastic hips were reviewed. Evaluation was made of a total of 68 patients comprising 64 females and 4 males, classified into two groups. Patients with BMI < 30 kg/m2 formed the non-obese group and patients with BMI ≥ 30 kg/m2 the obese group.

RESULTS

The mean age was 44.67 ± 6.49 years. BMI was < 30 in 44 (64.7%) patients and > 30 in 24 (35.3%) patients. The data analysis showed that mean surgical time, anaesthesia duration and re-admission rate were significantly higher in the group with BMI ≥ 30(obese) as compared to the group with BMI < 30 (non-obese) (p < 0.01). The complication rate was determined to be higher in the obese group (p < 0.05).

CONCLUSION

Obese patients performed with total hip arthroplasty for high-riding dysplastic hips had more complications and higher rates of re-admission to hospital compared with the non-obese patients.

Successful surgical closure of infected abdominal wounds following preconditioning with negative pressure wound therapy

PURPOSE

Traditionally, previous wound infection was considered a contraindication to secondary skin closure; however, several case reports describe successful secondary wound closure of wounds "preconditioned" with negative pressure wound therapy (NPWT). Although this has been increasingly applied in daily practice, a systematic analysis of its feasibility has not been published thus far. The aim of this study was to evaluate secondary skin closure in previously infected abdominal wounds following treatment with NPWT.

METHODS

Single-center retrospective analysis of patients with infected abdominal wounds treated with NPWT followed by either secondary skin closure referenced to a group receiving open wound therapy. Endpoints were wound closure rate, wound complications (such as recurrent infection or hernia), and perioperative data (such as duration of NPWT or hospitalization parameters).

RESULTS

One hundred ninety-eight patients during 2013-2016 received a secondary skin closure after NPWT and were analyzed and referenced to 67 patients in the same period with open wound treatment after NPWT. No significant difference in BMI, chronic immunosuppressive medication, or tobacco use was found between both groups. The mean duration of hospital stay was 30 days with a comparable duration in both patient groups (29 versus 33 days, p = 0.35). Interestingly, only 7.7% of patients after secondary skin closure developed recurrent surgical site infection and in over 80% of patients were discharged with closed wounds requiring only minimal outpatient wound care.

CONCLUSION

Surgical skin closure following NPWT of infected abdominal wounds is a good and safe alternative to open wound treatment. It prevents lengthy outpatient wound therapy and is expected to result in a higher quality of life for patients and reduce health care costs.

Obesity affects outcomes of pancreatoduodenectomy

BACKGROUND

Obesity is a major global health problem, and it has reached epidemic proportions worldwide. Therefore, surgeons will confront an increasingly larger proportion of obese candidates for pancreatoduodenectomy (PD) in the future. Several small retrospective studies have been conducted to evaluate the role of Body Mass Index (BMI) in postoperative surgical complications after PD, with conflicting results. The aim of this study was to use a large multi-institutional database to clarify the impact of different levels of obesity after PD.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was queried for patients who underwent PD from 2014 to 2016. Patients were categorized in the following six BMI groups: <18.5 (Underweight), 18.5-24.9 (Normal Weight), 25-29.9 (Overweight), 30-34.9 (Class I obesity), 35-39.9 (Class II Obesity) and >40 (Class III Obesity). The primary outcomes of interest were 30-day mortality and morbidity after PD among the six BMI groups.

RESULTS

The final population consists of 10,316 patients. Class III is associated with higher risk of 30-day mortality (OR 2.56, 95% CI 1.25-5.25, p = 0.011), major complications (OR 2.23, 95% CI 1.54-3.22, p < 0.001), clinically relevant postoperative pancreatic fistula (OR 2.48, 95% CI 1.89-3.24, p < 0.001), surgical site infections (OR 2.06, 95% CI 1.61-2.65, p < 0.001) and wound dehiscence (OR 3.47, 95% CI 1.7-7.1, p < 0.001) in multivariable analysis.

CONCLUSIONS

In conclusion, our study shows that obesity is significantly associated with higher risk of postoperative complications in patients undergoing PD and patients with BMI≥40 have increased risk of mortality after PD.

Selected conditions associated with an increased incidence of incisional hernia: A review of molecular biology

BACKGROUND

Incisional hernias (IH) following a laparotomy, on average, occur in 10-20% of patients, however, little is known about its molecular basis. Thus, a better understanding of the molecular mechanisms could lead to the identification of key target(s) to intervene pre-and post-operatively.

METHODS

We examined the current literature describing the molecular mechanisms of IH and overlap these factors with smoking, abdominal aortic aneurysm, obesity, diabetes mellitus, and diverticulitis.

RESULTS

The expression levels of collagen I and III, matrix metalloproteinases, and tissue inhibitors of metalloproteases are abnormal in the extracellular matrix (ECM) of IH patients and ECM disorganization has an overlap with these comorbid conditions.

CONCLUSION

Understanding the pathophysiology of IH development and associated risk factors will allow physicians to identify patients that may be at increased risk for IH and to possibly act preemptively to decrease the incidence of IH.

Association of Genetic Risk of Obesity with Postoperative Complications Using Mendelian Randomization

BACKGROUND

The extent to which obesity and genetics determine postoperative complications is incompletely understood.

METHODS

We performed a retrospective study using two population cohorts with electronic health record (EHR) data. The first included 736,726 adults with body mass index (BMI) recorded between 1990 and 2017 at Vanderbilt University Medical Center. The second cohort consisted of 65,174 individuals from 12 institutions contributing EHR and genome-wide genotyping data to the Electronic Medical Records and Genomics (eMERGE) Network. Pairwise logistic regression analyses were used to measure the association of BMI categories with postoperative complications derived from International Classification of Disease-9 codes, including postoperative infection, incisional hernia, and intestinal obstruction. A genetic risk score was constructed from 97 obesity-risk single-nucleotide polymorphisms for a Mendelian randomization study to determine the association of genetic risk of obesity on postoperative complications. Logistic regression analyses were adjusted for sex, age, site, and race/principal components.

RESULTS

Individuals with overweight or obese BMI (≥25 kg/m2) had increased risk of incisional hernia (odds ratio [OR] 1.7-5.5, p < 3.1 × 10-20), and people with obesity (BMI ≥ 30 kg/m2) had increased risk of postoperative infection (OR 1.2-2.3, p < 2.5 × 10-5). In the eMERGE cohort, genetically predicted BMI was associated with incisional hernia (OR 2.1 [95% CI 1.8-2.5], p = 1.4 × 10-6) and postoperative infection (OR 1.6 [95% CI 1.4-1.9], p = 3.1 × 10-6). Association findings were similar after limitation of the cohorts to those who underwent abdominal procedures.

CONCLUSIONS

Clinical and Mendelian randomization studies suggest that obesity, as measured by BMI, is associated with the development of postoperative incisional hernia and infection.

Outpatient Surgical Management for Acquired Buried Penis

OBJECTIVE

To demonstrate the safety and feasibility of outpatient surgical management for patients with acquired buried penis (ABP).

METHODS

We conducted an Institutional Review Board approved review of patients who underwent surgical repair of ABP at a single institution from September 2014 to August 2017. Patient characteristics, operative details, and 30- and 90-day complications were assessed.

RESULTS

Sixteen patients underwent surgical repair of ABP at the University of Kentucky during the study period. Mean age was 54 years (range 44-62). Median body mass index (BMI) was 47.7 (range 25.5-53.3). Patients largely underwent penile liberation, escutcheonectomy, and split thickness skin grafting. Concurrent scrotoplasty and urethroplasty were performed in select cases. The majority of patients 10/16 (62.5%) were discharged on the same day of surgery, while the remaining 6/16 (37.5%) were outpatient extended stay-and were discharged on postoperative day 1. The 30- and 90-day complications were 19% and 25% respectively, all were Clavien II. Split thickness skin graft take was 100%, and technical success was achieved in all patients. Patients with complications had higher BMIs, higher rates of diabetes, and higher rates of tobacco use, though only BMI reached statistical significance (P = .0150, P = .5846, and P = .0632) respectively.

CONCLUSION

Multi component repair of adult ABP can be safely done on an outpatient basis without need for routine inpatient admission and complex algorithms. The most common complication is surgical site infection, which arose in the first 30 days postoperatively. Higher BMI was a significant risk factor for complications.

Can Patient Selection Explain the Obesity Paradox in Orthopaedic Hip Surgery? An Analysis of the ACS-NSQIP Registry

BACKGROUND

The "obesity paradox" is a phenomenon described in prior research in which patients who are obese have been shown to have lower postoperative mortality and morbidity compared with normal-weight individuals. The paradox is that clinical experience suggests that obesity is a risk factor for difficult wound healing and adverse cardiovascular outcomes. We suspect that the obesity paradox may reflect selection bias in which only the healthiest patients who are obese are offered surgery, whereas nonobese surgical patients are comprised of both healthy and unhealthy individuals. We questioned whether the obesity paradox (decreased mortality for patients who are obese) would be present in nonurgent hip surgery in which patients can be carefully selected for surgery but absent in urgent hip surgery where patient selection is minimized.

QUESTIONS/PURPOSES

(1) What is the association between obesity and postoperative mortality in urgent and nonurgent hip surgery? (2) How is obesity associated with individual postoperative complications in urgent and nonurgent hip surgery? (3) How is underweight status associated with postoperative mortality and complications in urgent and nonurgent hip surgery?

METHODS

We used 2011 to 2014 data from the American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) to identify all adults who underwent nonurgent hip surgery (n = 63,148) and urgent hip surgery (n = 29,047). We used logistic regression models, controlling for covariants including age, sex, anesthesia risk, and comorbidities, to examine the relationship between body mass _index (BMI) category (classified as underweight < 18.5 kg/m, normal 18.5-24.9 kg/m, overweight 25-29.9 kg/m, obese 30-39.9 kg/m, and morbidly obese > 40 kg/m) and adverse outcomes including 30-day mortality and surgical complications including wound complications and cardiovascular events.

RESULTS

For patients undergoing nonurgent hip surgery, regression models demonstrate that patients who are morbidly obese were less likely to die within 30 days after surgery (odds ratio [OR], 0.12; 95% confidence interval [CI], 0.01-0.57; p = 0.038) compared with patients with normal BMI, consistent with the obesity paradox. For patients undergoing urgent hip surgery, patients who are morbidly obese had similar odds of death within 30 days compared with patients with normal BMI (OR, 1.18; 95% CI, 0.76-1.76; p = 0.54). Patients who are morbidly obese had higher odds of wound complications in both nonurgent (OR, 4.93; 95% CI, 3.68-6.65; p < 0.001) and urgent cohorts (OR, 4.85; 95% CI, 3.27-7.01; p < 0.001) compared with normal-weight patients. Underweight patients were more likely to die within 30 days in both nonurgent (OR, 3.79; 95% CI, 1.10-9.97; p = 0.015) and urgent cohorts (OR, 1.47; 95% CI, 1.23-1.75; p < 0.001) compared with normal-weight patients.

CONCLUSIONS

Patients who are morbidly obese appear to have a reduced risk of death in 30 days after nonurgent hip surgery, but not for urgent hip surgery. Our results suggest that the obesity paradox may be an artifact of selection bias introduced by careful selection of the healthiest patients who are obese for elective hip surgery. Surgeons should continue to consider obesity a risk factor for postoperative mortality and complications such as wound infections for both urgent and nonurgent surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Association of body mass index with mortality and postoperative survival in renal cell cancer patients, a meta-analysis

Obesity is one of the major risk factors of cancer. However, how body mass index (BMI) influences the prognosis of renal cell cancer (RCC) patient is unclear. In this work, we have performed a meta-analysis to elucidate the role of abnormal weight in RCC mortality and postoperative survival. Articles related to BMI and RCC mortality as well as postoperative survival has been identified by searching PUBMED and ENBASE. Totally, 19 articles have been selected for this meta-analysis, 5 articles for RCC mortality and 14 for postoperative survival. Compared to normal weight, the estimated relative risks of RCC mortality are 0.71 (95% CI: 0.34–1.49), 1.19 (95% CI: 1.05–1.35) and 1.71 (95% CI: 1.27–2.00) respectively for the underweight, overweight and obesity patients. The risk of RCC mortality increase 5% for each 1 kg/m² increment of BMI. However, the estimated hazard ratios of cancer specific postoperative survival are 2.62 (95% CI: 1.67–4.11), 0.72 (95% CI: 0.63–0.83) and 0.66 (95% CI: 0.49–0.89) respectively for underweight, overweight and obesity RCC patients. The risk of hazard ratio decrease 5% for each 1 kg/m² increment of BMI. In addition, the hazard ratios of postoperative overall survival show a similar tendency. These results indicate an opposite association of BMI with mortality and postoperative survival in renal cell cancer patients.

Association of Body Mass Index With Infectious Complications in Free Tissue Transfer for Head and Neck Reconstructive Surgery

Importance

Elevated body mass index (BMI) has been proposed as a risk factor for morbidity and mortality among patients undergoing surgery. Conversely, an elevated BMI may confer a protective effect on perioperative morbidity.

Objective

To examine whether an elevated BMI is an independent risk factor for perioperative and postoperative infectious complications after free tissue transfer in head and neck reconstructive surgery.

Design, Setting, and Participants

This cohort study included patients undergoing major head and neck surgery requiring free tissue transfer at a tertiary care center. Data were collected for 415 patients treated from January 1, 2007, through December 31, 2014.

Main Outcomes and Measures

The outcome of interest was postoperative infection and complications after head and neck surgery using free flaps. Covariates considered for adjustment in the statistical model included alcohol consumption (defined as >5 drinks per day [eg, 360 mL of beer, 150 mL of wine, or 45 mL of 80-proof spirits]), type 2 diabetes, prior radiotherapy, anesthesia time, hypothyroidism, smoking, American Society of Anesthesiologists classification, antibiotic regimen received (defined as a standard regimen of a first- or second-generation cephalosporin with or without metronidazole hydrochloride vs an alternative antibiotic regimen for patients allergic to penicillin), and primary surgeon. A multiple logistic regression model was developed for the incidence of the infection end point as a function of elevated BMI (>30.0).

Results

Among the 415 patients included in this study (277 men [66.7%] and 138 women [33.2%]; mean [SD] age, 61.5 [13.9] years), type 2 diabetes and use of an alternative antibiotic regimen were found to be independently associated with increased infectious complications after free flap surgery of the head and neck, with estimated odds ratios of 2.78 (95% CI, 1.27-6.09) and 2.67 (95% CI, 1.14-6.25), respectively, in the multiple logistic regression model. However, a high BMI was not found to be statistically significant as an independent risk factor for postoperative infectious complication (estimated odds ratio, 1.19; 95% CI, 0.48-2.92).

Conclusions and Relevance

Elevated BMI does not seem to play a role as an independent risk factor in postoperative complications in free tissue transfer in head and neck surgery.

Economies of scale: body mass index and costs of cardiac surgery in Ontario, Canada

An obesity paradox has been described, whereby obese patients have better health outcomes than normal weight patients in certain clinical situations, including cardiac surgery. However, the relationship between body mass index (BMI) and resource utilization and costs in patients undergoing coronary artery bypass graft (CABG) surgery is largely unknown. We examined resource utilization and cost data for 53,224 patients undergoing CABG in Ontario, Canada over a 10-year period between 2002 and 2011. Data for costs during hospital admission and for a 1-year follow-up period were derived from the Institute for Clinical Evaluative Sciences, and analyzed according to pre-defined BMI categories using analysis of variance and multivariate models. BMI independently influenced healthcare costs. Underweight patients had the highest per patient costs ($50,124 ± $36,495), with the next highest costs incurred by morbidly obese ($43,770 ± $31,747) and normal weight patients ($42,564 ± $30,630). Obese and overweight patients had the lowest per patient costs ($40,760 ± $30,664 and $39,960 ± $25,422, respectively). Conversely, at the population level, overweight and obese patients were responsible for the highest total yearly population costs to the healthcare system ($92 million and $50 million, respectively, compared to $4.2 million for underweight patients). This is most likely due to the high proportion of CABG patients falling into the overweight and obese BMI groups. In the future, preoperative risk stratification and preparation based on BMI may assist in reducing surgical costs, and may inform health policy measures aimed at the management of weight extremes in the population.

Risk Factors for Surgical Site Infections Following Neurosurgical Spinal Fusion Operations: A Case Control Study

OBJECTIVE To determine risk factors for the development of surgical site infections (SSIs) in neurosurgery patients undergoing spinal fusion. DESIGN Retrospective case-control study. SETTING Large, academic, quaternary care center. PATIENTS The study population included all neurosurgery patients who underwent spinal fusion between August 1, 2009, and August 31, 2013. Cases were defined as patients in the study cohort who developed an SSI. Controls were patients in the study cohort who did not develop an SSI. METHODS To achieve 80% power with an ability to detect an odds ratio (OR) of 2, we performed an unmatched case-control study with equal numbers of cases and controls. RESULTS During the study period, 5,473 spinal fusion procedures were performed by neurosurgeons in our hospital. With 161 SSIs recorded during the study period, the incidence of SSIs associated with these procedures was 2.94%. While anterior surgical approach was found to be a protective factor (OR, 0.20; 95% confidence interval [CI], 0.08-0.52), duration of procedure (OR, 1.58; 95% CI, 1.29-1.93), American Society of Anesthesiologists score of 3 or 4 (OR, 1.79; 95% CI, 1.00-3.18), and hospitalization within the prior 30 days (OR, 5.8; 95% CI, 1.37-24.57) were found in multivariate analysis to be independent predictors of SSI following spinal fusion. Prior methicillin-resistant Staphylococcus aureus (MRSA) nares colonization was highly associated with odds 20 times higher of SSI following spinal fusion (OR, 20.30; 95% CI, 4.64-8.78). CONCLUSIONS In additional to nonmodifiable risk factors, prior colonization with MRSA is a modifiable risk factor very strongly associated with development of SSI following spinal fusion. Infect Control Hosp Epidemiol 2017;38:348-352.

Risk stratification for the development of respiratory adverse events following vascular surgery using the Society of Vascular Surgery's Vascular Quality Initiative

OBJECTIVE

Postoperative respiratory adverse events (RAEs) are associated with high rates of morbidity and mortality in general surgery, however, little is known about these complications in the vascular surgery population, a frail subset with multiple comorbidities. The objective of this study was to describe the contemporary incidence of RAEs in vascular surgery patients, the risk factors for this complication, and the overall impact of RAEs on patient outcomes.

METHODS

The Vascular Quality Initiative was queried (2003-2014) for patients who underwent endovascular abdominal aortic repair, open abdominal aortic aneurysm repair, thoracic endovascular aortic repair, suprainguinal bypass, or infrainguinal bypass. A mixed-effects logistic regression model determined the independent risk factors for RAEs. Using a random 85% of the cohort, a risk prediction score for RAEs was created, and the score was validated using the remaining 15% of the cohort, comparing the predicted to the actual incidence of RAE and determining the area under the receiver operating characteristic curve. The independent risk of in-hospital mortality and discharge to a nursing facility associated with RAEs was determined using a mixed-effects logistic regression to control for baseline patient characteristics, operative variables, and other postoperative adverse events.

RESULTS

The cohort consisted of 52,562 patients, with a 5.4% incidence of RAEs. The highest rates of RAEs were seen in current smokers (6.1%), recent acute myocardial infarction (10.1%), symptomatic congestive heart failure (9.9%), chronic obstructive pulmonary disease requiring oxygen therapy (11.0%), urgent and emergent procedures (6.4% and 25.9%, respectively), open abdominal aortic aneurysm repairs (17.6%), in situ suprainguinal bypasses (9.68%), and thoracic endovascular aortic repairs (9.6%). The variables included in the risk prediction score were age, body mass index, smoking status, congestive heart failure severity, chronic obstructive pulmonary disease severity, degree of renal insufficiency, ambulatory status, transfer status, urgency, and operative type. The predicted compared with the actual RAE incidence were highly correlated, with a correlation coefficient of 0.943 (P < .0001) and a c-statistic = 0.818. RAEs had a significantly higher rates of in-hospital mortality (25.4% vs 1.2%; P < .0001; adjusted odds ratio, 5.85; P < .0001), and discharge to a nursing facility (57.8% vs 19.0%; P < .0001; adjusted odds ratio, 3.14; P < .0001).

CONCLUSIONS

RAEs are frequent and one of the strongest risk factors for in-hospital mortality and inability to be discharged home. Our risk prediction score accurately stratifies patients based on key demographics, comorbidities, presentation, and operative type that can be used to guide patient counseling, preoperative optimization, and postoperative management. Furthermore, it may be useful in developing quality benchmarks for RAE following major vascular surgery.

Pharmacokinetic and Pharmacodynamic Evaluation of a Weight-Based Dosing Regimen of Cefoxitin for Perioperative Surgical Prophylaxis in Obese and Morbidly Obese Patients

The objective of this study was to determine the pharmacokinetics and pharmacodynamics (PK/PD) of a weight-based cefoxitin dosing regimen for surgical prophylaxis in obese patients. Patients received a single dose of cefoxitin at 40 mg/kg based on total body weight. Cefoxitin samples were obtained over 3 h from serum and adipose tissue, and concentrations were determined by validated high-performance liquid chromatography. Noncompartmental pharmacokinetic analysis was performed, followed by Monte Carlo simulations to estimate probability of target attainment (PTA) for Staphylococcus aureus, Escherichia coli, and Bacteroides fragilis over 4-h periods postdose. Thirty patients undergoing bariatric procedures were enrolled. The body mass index (mean ± standard deviation [SD])was 45.9 ± 8.0 kg/m(2) (range, 35.0 to 76.7 kg/m(2)); the median cefoxitin dose was 5 g (range, 4.0 to 7.5 g). The mean maximum concentrations were 216.15 ± 41.80 μg/ml in serum and 12.62 ± 5.89 in tissue; the mean tissue/serum ratio was 8% ± 3%. In serum, weight-based regimens achieved ≥90% PTA (goal time during which free [unbound] drug concentrations exceed pathogen MICs [fT>MIC] of 100%) for E. coli and S. aureus over 2 h and for B. fragilis over 1 h; in tissue this regimen failed to achieve goal PTA at any time point. The 40-mg/kg regimens achieved higher PTAs over longer periods in both serum and tissue than did the standard 2-g doses. However, although weight-based cefoxitin regimens were better than fixed doses, achievement of desired pharmacodynamic targets was suboptimal in both serum and tissue. Alternative dosing regimens and agents should be explored in order to achieve more favorable antibiotic performance during surgical prophylaxis in obese patients.

Academic leadership and Lean Six Sigma

Purpose

– The purpose of this paper is to demonstrate the ability to researchers of using design of experiments (DoE) as a structured and systematic approach to performing systematic literature reviews. The authors demonstrate a simple case study illustrating the application of DoE in executing a systematic literature review on two popular topics in higher education: academic leadership and Lean Six Sigma.

Design/methodology/approach

– The methodology involves the systematic literature review of linking academic leadership with terms such as Lean, Six Sigma, Total Quality Management, Maturity Model and Continuous Improvement. The main tool used to structure the systematic literature review is a Taguchi Orthogonal Array design, specifically an L16 grid and the method is verified by conducting another review, replacing the term academic leadership with simply leadership.

Findings

– The approach identified at first no research papers linking the terms; however, when academic leadership was replaced with university, 19 research papers where discovered. The verification exercise, linking just leadership with the other search string generated over 1,000 results – demonstrating that the tool can find large volumes of articles if they exist, the search was completed for a ten year time frame – 2004 to 2014.

Research limitations/implications

– The case study focussed on a field which is known to have little current research and the verification exercise deliberately targeted a known large body of research. The authors will continue to use the approach and refine the technique over time.

Practical implications

– This approach would help any researcher despite of their discipline to identify opportunities and gaps in the current literature.

Originality/value

– The paper shows how DoE can be used in an academic research-based process. No other literature review approach currently exists which uses Taguchi approach to DoE to filter the search criteria.

The Effect of Body Mass Index on Surgical Outcomes in Patients Undergoing Pancreatic Resection: A Systematic Review and Meta-Analysis

OBJECTIVES

Previous studies that investigated the association between body mass index (BMI) and pancreatectomy outcomes have produced conflicting conclusions. We conducted this meta-analysis to assess the association between them.

METHODS

We searched PubMed, EMBASE, and Cochrane Library databases up to December 28, 2014. Patients were divided into high-BMI group (BMI ≥ 25 kg/m) and normal-BMI group (BMI < 25 kg/m). Postoperative and intraoperative outcomes were evaluated. Meta-regression and subgroup analysis were performed to evaluate any factors accountable for the heterogeneity. Meta-analysis was performed using a random-effect model.

RESULTS

We included 22 studies involving 8994 patients. Patients in the high-BMI group had significantly increased postoperative pancreatic fistula rate (odds ratio [OR],1.96; 95% confidence interval [CI], 1.43-2.67), delayed gastric emptying rate (OR, 1.62; 95% CI, 1.15-2.29), wound infection rate (OR, 1.43; 95% CI, 1.07-1.93), operation time (mean difference [MD],15; 95% CI, 13.40-16.60), blood loss (MD, 270.71; 95% CI, 248.93-292.49), and length of hospital stay (MD, 2.87; 95% CI, 1.51-4.24). For modest heterogeneity in postoperative pancreatic fistula, regional distribution tended to be the contributor.

CONCLUSIONS

High BMI not only increased the surgical difficulty but also decreased the surgical safety for pancreatectomy.

Predictive Value of Nutritional Markers for Wound Healing Complications in Bariatric Patients Undergoing Panniculectomy

BACKGROUND

Hypoproteinemia and nutritional deficiencies are common after bariatric surgery, and although massive weight loss (MWL) patients experience increased wound complication rates, the association has not been causatively determined.

OBJECTIVES

This study investigated preoperative nutritional parameters and wound complications in MWL patients (postbariatric and diet-controlled) undergoing panniculectomy at 2 academic institutions.

METHODS

One hundred sixty-one consecutive patients undergoing elective panniculectomy after bariatric surgery or diet-controlled weight loss were identified. Patient demographics and nutritional indices (serum protein, albumin, and micronutrient levels) were analyzed. Complications including wound separation, infection, and operative debridements were compared. Post hoc comparisons tested for correlation between complications and nutritional markers.

RESULTS

Postbariatric patients lost an average of 151 lb and presented at an average of 32 months after gastric bypass. Diet-controlled weight loss patients lost an average of 124 lb. Despite MWL, albumin levels were higher in the bariatric group (3.8 vs 3.4 g/dL, P < 0.05). Conversely, bariatric patients experienced increased wound complications (27% vs 14%; P < 0.05). Factors which were found to correlate to increased risk of wound dehiscence and infection were elevated body mass index at time of panniculectomy and amount of tissue removed. Multivariate analysis did not show serum albumin or percent weight loss to independently predict complications.

CONCLUSIONS

Bariatric patients presenting for elective operations are at risk for protein and micronutrient deficiency. Despite aggressive replacement and normalization of nutritional markers, bariatric patients experience increased wound complications when compared to nonbariatric patients and traditional measures of nutritional evaluation for surgery may be insufficient in bariatric patients.

Impact of Obesity on Robot-Assisted Distal Pancreatectomy

BACKGROUND

Obesity has been steadily increasing in the United States. The effect of body mass index (BMI) on surgical outcomes in pancreatic surgery is still controversial. Currently, there is no report related to obesity and robotic pancreatic surgery. The purpose of this study was to evaluate the impact of BMI on the surgical outcomes of both nonobese and obese patients undergoing robot-assisted distal pancreatectomy (RADP).

METHODS

A prospectively collected database for RADP was retrieved for analysis. Patients were categorized as obese (BMI ≥30 kg/m(2)) and nonobese (BMI <30 kg/m(2)). Demographics, perioperative data, American Society of Anesthesiologists score, diagnosis, conversion rate, morbidity, surgical mortality, pancreatic fistula rate, and length of stay were compared.

RESULTS

A total for 85 RADP were included, with 57 (67%) in the nonobese group and 28 (33%) in the obese group. No differences were found between nonobese and obese patients regarding demographic, preoperative risk, and perioperative parameters and mortality. There was a trend in the obese group associated with a higher rate of postoperative complications, but it was statistically insignificant. Clinically significant pancreatic fistula (grade B) occurred in 28.5% of obese patients and in 7% of nonobese patients, but without statistical significance (P = .064).

CONCLUSIONS

Obesity does not have a significant impact on the perioperative outcomes and surgical risks for patients undergoing RADP, but high BMI may be a predictor for pancreatic fistula after RADP.

Bronchospasm in obese patients undergoing elective laparoscopic surgery under general anesthesia

Background

Existing data suggest that obesity correlates with airway hyper-reactivity. However, the incidence of bronchospasm during bariatric surgery in obese patients has not been well studied.

Methods

This was a prospective observational study comparing 50 obese versus 50 non obese patients undergoing elective laparoscopic surgery over a 2 year period. Bronchospasm was detected clinically by auscultation and was confirmed by measuring peak airway pressure during mechanical ventilation. Blood gases were measured at predetermined time intervals intraoperatively. Categorical variables were analyzed using Fisher’s exact test, while numerical variables within and between groups were compared using repeated measures general linear model.

Results

The incidence of bronchospasm was significantly higher in obese compared to non obese patients (P = 0.027). Peak airway pressures and blood gases differed significantly when comparing non obese patients versus obese patients without bronchospasm versus obese patients with bronchospasm. Hypoventilation resulting in gradual increase of arterial PaCO₂ was noted in all groups during surgery.

Conclusion

The incidence of bronchospasm is higher in obese patients compared to non obese patients undergoing elective laparoscopic surgery. Airway pressures and blood gas values in obese patients are somewhere between values in non obese patients and values in patients with bronchospasm, thereby implying that obesity is associated with a state where bronchial smooth muscles are not fully relaxed. Consideration of increased airway reactivity in obese patients undergoing laparoscopic surgery is important for improved patient care and uneventful anesthetic course.

Matched Case-Control Analysis Comparing Laparoscopic and Open Pylorus-preserving Pancreaticoduodenectomy in Patients With Periampullary Tumors

OBJECTIVES

To evaluate the safety, feasibility, and oncologic outcomes of laparoscopic pylorus-preserving pancreaticoduodenectomy (L-PPPD) to treat periampullary tumors. The clinical outcomes of L-PPPD were compared with open pylorus-preserving pancreaticoduodenectomy (O-PPPD).

BACKGROUND

Despite recent advances in laparoscopic pancreatic surgery, few studies have compared L-PPPD with O-PPPD. The safety, short-term clinical benefits, and oncologic outcomes of L-PPPD remain controversial.

METHODS

Between January 2007 and December 2012, a total of 2192 patients diagnosed with periampullary tumors were treated with curative resection at our institution. Of these patients, 137 underwent a laparoscopic approach and 2055 an open technique. A retrospective study was performed to evaluate the safety, feasibility, and oncologic outcomes of L-PPPD compared with O-PPPD.

RESULTS

The mean operation time for the L-PPPD group was longer than for the O-PPPD group (P < 0.001). Estimated blood loss was similar, as was the incidence of complications, such as pancreatic fistula and delayed gastric empting (P > 0.05). The mean number of analgesic injections administered was lower in the L-PPPD group than in the O-PPPD group (P < 0.001), and the mean duration of the postoperative hospital stays was shorter (P < 0.001). The surgical resection margins and the number of lymph nodes in the resected specimens did not differ between the 2 groups, and there was no significant difference in overall survival curves.

CONCLUSIONS

L-PPPD had the typical advantages of minimally invasive abdominal procedures, such as less pain, shorter hospital stay, and quicker recovery. It is technically safe and feasible, and has favorable oncologic outcomes in comparison with O-PPPD in patients with periampullary tumors.

Increased Risk of Infection in Obese Adolescents After Pedicle Screw Instrumentation for Idiopathic Scoliosis

STUDY DESIGN

Original research.

OBJECTIVE

To evaluate perioperative risk factors associated with obesity in children undergoing posterior spinal fusion for adolescent idiopathic scoliosis. The authors hypothesized that patients with a high body mass index (BMI) percentile would be associated with increased morbidity as measured by various intraoperative parameters.

SUMMARY OF BACKGROUND DATA

Few studies have evaluated the effects of increased BMI in children undergoing surgery. Adolescent idiopathic scoliosis represents 80% of idiopathic scoliosis cases and is the most common indication for surgery.

METHODS

Patients were divided into 3 groups: normal weight (n = 144) (5% < BMI < 85%), overweight (n = 25) (BMI > 85% to 95%), and obese (n = 38) (BMI > 95%). Patients with BMI less than 5% were excluded from this study because they were underweight. Perioperative data were collected and analyzed based on differences between groups.

RESULTS

A total of 207 patients were included in this study. There was a significant difference in the length of anesthesia (p = .032). The rate of infection was 11% in the obese group, 12% in the overweight group, and 3% in the normal weight group (p = .03).

CONCLUSIONS

Even with pedicle screw instrumentation, the researchers saw an increase in infection in overweight and obese patients. Patients should be counseled before surgery for weight loss to limit surgical complications such as possible risk of postoperative wound infection.

Obesity and surgical wound healing: a current review

Objective. The correlation between obesity and deficient wound healing has long been established. This review examines the current literature on the mechanisms involved in obesity-related perioperative morbidity. Methods. A literature search was performed using Medline, PubMed, Cochrane Library, and Internet searches. Keywords used include obesity, wound healing, adipose healing, and bariatric and surgical complications. Results. Substantial evidence exists demonstrating that obesity is associated with a number of postoperative complications. Specifically in relation to wound healing, explanations include inherent anatomic features of adipose tissue, vascular insufficiencies, cellular and composition modifications, oxidative stress, alterations in immune mediators, and nutritional deficiencies. Most recently, advances made in the field of gene array have allowed researchers to determine a few plausible alterations and deficiencies in obese individuals that contribute to their increased risk of morbidity and mortality, especially wound complications. Conclusion. While the literature discusses how obesity may negatively affect health on various of medical fronts, there is yet to be a comprehensive study detailing all the mechanisms involved in obesity-related morbidities in their entirety. Improved knowledge and understanding of obesity-induced physiological, cellular, molecular, and chemical changes will facilitate better assessments of surgical risks and outcomes and create efficient treatment protocols for improved patient care of the obese patient population.

Risk factors of surgical site infections after supratentorial elective surgery: a focus on the efficacy of the wound-drain-tip culture

BACKGROUND

Surgical site infection (SSI) is one of the most dangerous complications after neurological surgery and is related to additional postoperative hospital days and an increased risk of death. One method for the early detection of SSI, the wound-drain-tip culture (WDC), has been widely used. However, no investigations on the relation between SSIs and wound drains after neurological surgery have been conducted. We performed this study to identify the risk factors for SSIs and to assess the relationship between SSIs and the results of WDC after elective supratentorial craniotomy.

METHODS

A total of 535 patients underwent elective primary supratentorial craniotomy, and the results of their WDC were analyzed. The mean follow-up period was 14.1 ± 12.2 months. In 347 (64.9 %) patients, the wound drain was removed within 2 days after operation.

RESULTS

Until follow-up, 14 (2.62 %) patients suffered from SSIs. Among the 21 patients with positive WDCs, 8 (38.1 %) patients experienced SSIs. The organisms cultured from the SSIs were matched with the WDC results in 7 (87.5 %) patients. In the multivariate analysis, underweight group (OR = 15.41, p = 0.002), maintenance wound drain over 3 days (OR = 4.202, p = 0.043), and positive WDC (OR = 36.67, p < 0.001) were significantly associated with postoperative SSIs. In 6 (85.7 %) of 7 patients with a positive WDC for Serratia marcescens, SSIs ultimately developed.

CONCLUSIONS

The prognostic value of the positive WDC still falls short of our expectations in the field of neurological surgery. And, the positive WDC results should be cautiously interpreted, considering the virulence of the cultured micro-organisms.

Morbidities of lung cancer surgery in obese patients

BACKGROUND

Obesity is a risk factor for increased perioperative morbidity and mortality in surgical patients. There have been limited studies to correlate the morbidity of lung cancer resection with obesity.

METHODS

We performed a retrospective study of patients who underwent surgical resection for lung cancer at the Medical College of Wisconsin, Milwaukee, from 2006 to 2010. Data on patient demographics, weight, pathological findings, and hospital course were abstracted after appropriate institutional review board approval. Perioperative morbidity was defined as atrial fibrillation, heart failure, respiratory failure, pulmonary embolism, or any medical complications arising within 30 days after surgery. The Fisher exact test was used to test the association between body mass index (BMI) and perioperative morbidities.

RESULTS

Between 2006 and 2010, 320 lung resections were performed for lung cancer. The median age was 67 (interquartile range, 59-75) years, and 185 (57.8%) were females. A total of 121 (37.8%) of patients had a BMI lower than 25, and 199 (62.18%) patients had a BMI of 25 or higher. The 30-day mortality rate was 1.8% (n = 6) in the whole group; only 2 of these patients had a BMI of 25 or higher. Perioperative morbidity occurred in 28 (23.14%) of patients with a normal BMI and in 47 (23.61%) of patients with a BMI of 25 or higher (P = .54). Specific morbidities encountered by patients with normal versus BMI of 25 or higher were as follows: atrial fibrillation, 11 (9.09%) versus 24 (12.06%) (P = .46); pulmonary embolism, 1 (0.83%) versus 3 (1.51%) (P = 1.0); congestive heart failure, 2 (1.65%) versus 2 (1.01%) (P = .63); renal failure, 4 (3.3%) versus 2 (1.0%) (P = .29); respiratory failure, 12 (9.92%) versus 17 (8.54%) (P = .69); and acute respiratory distress syndrome, 2 (1.65%) versus 1 (0.50%) (P = .55). The median hospital stay was 5 days in the lower BMI group and 4 days in the BMI of 25 or higher group (P = .52).

CONCLUSIONS

Overweight and normal weight patients do not differ significantly in rates of perioperative morbidities, 30-day mortality, and length of stay. Our study indicates that potential curative surgical resections can be offered to even significantly overweight patients.

Obesity increases operating room time for lobectomy in the society of thoracic surgeons database

BACKGROUND

Obesity has become a major epidemic in the United States. Although research suggests obesity does not increase major morbidity or mortality after thoracic operations, it likely results in greater use of health care resources.

METHODS

We examined all patients in The Society of Thoracic Surgeons General Thoracic Surgery database with primary lung cancer who underwent lobectomy from 2006 to 2010. We investigated the impact of body mass index (BMI) on total operating room time using a linear mixed-effects regression model and multiple imputations to account for missing data. Secondary outcomes included postoperative length of stay and 30-day mortality. Covariates included age, sex, race, forced expiratory volume, smoking status, Zubrod score, prior chemotherapy or radiation, steroid use, number of comorbidities, surgical approach, hospital lobectomy volume, hospital percent obesity, and the addition of mediastinoscopy or wedge resection.

RESULTS

A total of 19,337 patients were included. The mean BMI was 27.3 kg/m2, with 4,898 patients (25.3%) having a BMI of 30 kg/m2 or greater. The mean total operating room time, length of stay, and 30-day mortality were 240 minutes, 6.7 days, and 1.8%, respectively. For every 10-unit increase in BMI, mean operating room time increased by 7.2 minutes (range, 4.8 to 8.4 minutes; p<0.0001). Higher hospital lobectomy volume and hospital percentage of obese patients did not affect the association between BMI and operative time. Body mass index was not associated with 30-day mortality or increased length of stay.

CONCLUSIONS

Increased BMI is associated with increased total operating room time, regardless of institutional experience with obese patients.

Pay for obesity? Pay-for-performance metrics neglect increased complication rates and cost for obese patients

BACKGROUND

Rates of surgical complications are increasingly being used for pay-for-performance reimbursement structures. We hypothesize that morbid obesity has a significant effect on complication rates and costs following commonly performed general surgical procedures.

METHODS

We studied 30,502 patients who underwent cholecystectomy for cholecystitis and 6,390 patients who underwent appendectomy for acute appendicitis using administrative claims data from seven Blue Cross and Blue Shield Plans over a 7-year period (2002-2008). We compared 30-day complications as well as total 30-day direct medical costs for obese and non-obese patients. Multivariate regressions were performed to determine the relationship of morbid obesity to complications and cost.

RESULTS

Obese patients were more likely to have a complication within 30 days after surgery than non-obese patients (19.2% vs. 15.7% for cholecystectomy, p < 0.0001; 20.2% vs. 15.2%, p < 0.0001, for appendectomy). The mean total 30-day postoperative cost for obese patients were $1,109 higher following a cholecystectomy (p < 0.0001) and $666 higher following an appendectomy (p = 0.09).

CONCLUSION

Morbid obesity is associated with a higher rate of complications for two commonly performed general surgical procedures and is associated with higher costs for cholecystectomy. Pay-for-performance metrics should account for the increased risk of complications and higher cost in this population.

Determinants of outcomes in pancreatic surgery and use of hospital resources

BACKGROUND AND OBJECTIVES

Outcomes for patients undergoing major pancreatic surgery have improved, but a subset of patients that significantly utilize more resources exists. Variables that can lead to an increase in resource utilization in patients undergoing pancreatic surgery were identified.

METHODS

Patients undergoing pancreatic surgery for neoplasms were identified from the NSQIP database (2006-2008). Indices associated with increased resource utilization that we included were operative time (OT), length of stay (LOS), intraoperative RBC transfusion, return to operating room, and occurrence of postoperative complications. Analysis of covariance and multivariable logistic regression were performed.

RESULTS

The 4,306 included patients had a median age of 66 years and 50.3% were males. The 30-day morbidity and mortality were 29.3% and 3.2%, respectively. Median OT was 362  min and median LOS was 10 days. Malignancy, neoadjuvant radiation, and medical co-morbidities were associated with increased OT (P < 0.0001 for all). Declining preoperative functional status was the most important predictor of LOS (P < 0.0001). Age, male gender, hypertension, severe COPD, and higher BMI were significantly associated with postoperative complications (P < 0.050 for all).

CONCLUSIONS

Morbidity after pancreatic surgery remains high. Age, obesity, performance status, medical co-morbidities, and neoadjuvant radiation affect outcomes and may lead to increased use of hospital resources.

Prognostic value of body mass index on short-term and long-term outcome after resection of esophageal cancer

INTRODUCTION

Cachexia and obesity have been suggested to be risk factors for postoperative complications. However, high body mass index (BMI) might result in a higher R0-resection rate because of the presence of more fatty tissue surrounding the tumor. The purpose of this study was to investigate whether BMI is of prognostic value with regard to short-term and long-term outcome in patients who undergo esophagectomy for cancer.

METHODS

In 556 patients who underwent esophagectomy (1991-2007), clinical and pathological outcome were compared between different BMI classes (underweight, normal weight, overweight, obesity).

RESULTS

Overall morbidity, mortality, and reoperation rate did not differ in underweight and obese patients. However, severe complications seemed to occur more often in obese patients (p = 0.06), and the risk for anastomotic leakage increased with higher BMI (12.5% in underweight patients compared with 27.6% in obese patients, p = 0.04). Histopathological assessment showed comparable pTNM stages, although an advanced pT stage was seen more often in patients with low/normal BMI (p = 0.02). A linear association between BMI and R0-resection rate was detected (p = 0.02): 60% in underweight patients compared with 81% in obese patients. However, unlike pT-stage (p < 0.001), BMI was not an independent predictor for R0 resection (p = 0.12). There was no significant difference in overall or disease-free 5-year survival between the BMI classes (p = 0.25 and p = 0.6, respectively).

CONCLUSIONS

BMI is not of prognostic value with regard to short-term and long-term outcome in patients who undergo esophagectomy for cancer and is not an independent predictor for radical R0 resection. Patients oncologically eligible for esophagectomy should not be denied surgery on the basis of their BMI class.

A comparison of desflurane versus propofol: the effects on early postoperative lung function in overweight patients

BACKGROUND

In this study, we evaluated the influence of propofol versus desflurane anesthesia in overweight patients on postoperative lung function and pulse oximetry values.

METHODS

We prospectively studied 134 patients with body mass indices of 25 to 35 kg/m(2) undergoing minor peripheral surgery lasting 40 to 120 minutes. Patients were randomly assigned to receive propofol (total IV anesthesia) or desflurane anesthesia via a tracheal tube targeting bispectral index values of 40 to 60. Premedication, adjuvant drug usage, and ventilation were standardized. We measured oxyhemoglobin saturation and lung function preoperatively (baseline), and at 10 minutes, 0.5 hour, 2 hours, and 24 hours after tracheal extubation. All values were measured with the patient supine, in a 30° head-up position. Changes from preoperative baseline values were first analyzed for the impact of body mass index and type of anesthesia using univariate methods, followed by linear regression and multivariate analysis of variance.

RESULTS

Within the first 2 hours after surgery, the propofol group displayed lower oxyhemoglobin saturation (at 2 hours, mean ± SD, 93.8% ± 2.0% vs 94.6% ± 2.1%; P < 0.007) and lung function (forced vital capacity, forced expiratory volume exhaled in 1 second [FEV(1)], peak expiratory flow, midexpiratory flow [MEF], forced inspiratory vital capacity, and peak inspiratory flow; between 11% and 20% larger reduction from baseline in the propofol group, all P < 0.001) compared with the desflurane group. Even 24 hours after surgery, FEV(1), peak expiratory flow, MEF, forced inspiratory vital capacity, and peak inspiratory flow were reduced more in the propofol group (all P < 0.01). At 2 hours after extubation, increasing obesity was associated with decreasing FEV(1) and MEF in patients anesthetized with propofol but not desflurane (P < 0.01).

CONCLUSION

We conclude that, for superficial surgical procedures of up to 120 minutes, maintenance of anesthesia with propofol impairs early postoperative lung function and pulse oximetry values more than with desflurane. Furthermore, increasing obesity decreases pulmonary function at 2 hours after propofol anesthesia but not after desflurane anesthesia.

Restorative proctectomy with ileal pouch-anal anastomosis in obese patients

PURPOSE

The aim of this study was to assess outcomes of ileal pouch-anal anastomosis in obese patients compared with a matched cohort of nonobese patients.

METHODS

A review of all obese patients who underwent ileal pouch-anal anastomosis from 1998 to 2008 was performed. Obesity was defined as body mass index >or=30 kg/m. A matched control group of patients with body mass index within 18.5 to 25 kg/m was created. Primary end points included operative time, length of hospital stay, operative blood loss, and early (<or=6 wk) and long-term (>6 wk) postoperative complications.

RESULTS

Sixty-five obese patients (mean body mass index, 34.3 +/- 0.51 kg/m) underwent proctectomy with ileal pouch-anal anastomosis or proctocolectomy with ileal pouch-anal anastomosis. Mean body mass index of the control group was 22.45 +/- 0.2 kg/m (P < .0001). The most common diagnosis was mucosal ulcerative colitis (84.6%), followed by familial adenomatous polyposis (13.9%) and Crohn's disease (1.5%). The obese population had a higher incidence of cardiorespiratory comorbidities (P = .044), and a trend for steroid and immunosuppressive therapy (P = .06) preoperatively. Obese patients required longer operative time (P = .001) and longer hospital stay (P = .009). Early postoperative complications were comparable (P > .05). Long-term outcomes were also similar, except for a higher incidence of incisional hernia in the obese group (P = .01).

CONCLUSIONS

The overall postoperative complication rate in obese patients undergoing ileal pouch-anal anastomosis was similar to a matched nonobese cohort of patients. However, longer operative time, longer length of stay, and a higher rate of incisional hernia were noted in the obese population. Obese patients should be appropriately consulted about these issues before undergoing ileal pouch-anal anastomosis.

Developing a risk stratification model for surgical site infection after abdominal hysterectomy

OBJECTIVE

The incidence of surgical site infection (SSI) after hysterectomy ranges widely from 2% to 21%. A specific risk stratification index could help to predict more accurately the risk of incisional SSI following abdominal hysterectomy and would help determine the reasons for the wide range of reported SSI rates in individual studies. To increase our understanding of the risk factors needed to build a specific risk stratification index, we performed a retrospective multihospital analysis of risk factors for SSI after abdominal hysterectomy.

METHODS

Retrospective case-control study of 545 abdominal and 275 vaginal hysterectomies from July 1, 2003, to June 30, 2005, at 4 institutions. SSIs were defined by using Centers for Disease Control and Prevention/National Nosocomial Infections Surveillance criteria. Independent risk factors for abdominal hysterectomy were identified by using logistic regression.

RESULTS

There were 13 deep incisional, 53 superficial incisional, and 18 organ-space SSIs after abdominal hysterectomy and 14 organ-space SSIs after vaginal hysterectomy. Because risk factors for organ-space SSI were different according to univariate analysis, we focused further analyses on incisional SSI after abdominal hysterectomy. The maximum serum glucose level within 5 days after operation was highest in patients with deep incisional SSI, lower in patients with superficial incisional SSI, and lowest in uninfected patients (median, 189, 156, and 141 mg/dL, respectively; P = .005). Independent risk factors for incisional SSI included blood transfusion (odds ratio [OR], 2.4) and morbid obesity (body mass index [BMI], >35; OR, 5.7). Duration of operation greater than the 75th percentile (OR, 1.7), obesity (BMI, 30-35; OR, 3.0), and lack of private health insurance (OR, 1.7) were marginally associated with increased odds of SSI.

CONCLUSIONS

Incisional SSI after abdominal hysterectomy was associated with increased BMI and blood transfusion. Longer duration of operation and lack of private health insurance were marginally associated with SSI.

The obesity paradox: body mass index and outcomes in patients undergoing nonbariatric general surgery

OBJECTIVE

We sought to examine the effect of body mass index (BMI) on 30-day morbidity and mortality in a large cohort of patients undergoing nonbariatric general surgery.

SUMMARY BACKGROUND DATA

Obesity has long been considered a risk factor for poor outcomes from a variety of surgical procedures, yet recent studies of critically and chronically ill patients suggest that overweight and obese patients may paradoxically have better outcomes than "normal" weight patients.

METHODS

A prospective, multi-institutional, risk-adjusted cohort study of 118,707 patients undergoing nonbariatric general surgery who were included in the National Surgical Quality Improvement Program Participant Use database in 2005 and 2006 was performed. Outcomes and risk variables were compared across NIH-defined BMI class using analysis of variance, Bonferroni multiple comparisons of means tests, and multivariable logistic regression.

RESULTS

After adjusting for all significant perioperative risk factors, the risk of death according to BMI exhibited a reverse J-shaped relationship, with the highest rates in the underweight and morbidly obese extremes and the lowest rates in the overweight and moderately obese. Overweight (odds ratio, 0.85; 95% CI, 0.75-0.99) and moderately obese (odds ratio, 0.73; 95% CI, 0.57-0.94) patients had a significantly lower risk of death than normal weight patients. There was a progressive increase in the likelihood of a complication with increasing BMI class, almost entirely due to increasing rates of wound infection.

CONCLUSIONS

Overweight and moderately obese patients undergoing nonbariatric general surgery have paradoxically "lower" crude and adjusted risks of mortality compared with patients at a "normal" weight. This finding is in contrast to observations from the general population, confirming the existence of an "obesity paradox" in this patient population.