Sebastian D. Perez

Risk Factors for 30-Day Hospital Readmission among General Surgery Patients

BACKGROUND Hospital readmission within 30 days of an index hospitalization is receiving increased scrutiny as a marker of poor-quality patient care. This study identifies factors associated with 30-day readmission after general surgery procedures. STUDY DESIGN Using standard National Surgical Quality Improvement Project protocol, preoperative, intraoperative, and postoperative outcomes were collected on patients undergoing inpatient general surgery procedures at a single academic center between 2009 and 2011. Data were merged with our institutional clinical data warehouse to identify unplanned 30-day readmissions. Demographics, comorbidities, type of procedure, postoperative complications, and ICD-9 coding data were reviewed for patients who were readmitted. Univariate and multivariate analysis was used to identify risk factors associated with 30-day readmission. RESULTS One thousand four hundred and forty-two general surgery patients were reviewed. One hundred and sixty-three (11.3%) were readmitted within 30 days of discharge. The most common reasons for readmission were gastrointestinal problem/complication (27.6%), surgical infection (22.1%), and failure to thrive/malnutrition (10.4%). Comorbidities associated with risk of readmission included disseminated cancer, dyspnea, and preoperative open wound (p < 0.05 for all variables). Surgical procedures associated with higher rates of readmission included pancreatectomy, colectomy, and liver resection. Postoperative occurrences leading to increased risk of readmission were blood transfusion, postoperative pulmonary complication, wound complication, sepsis/shock, urinary tract infection, and vascular complications. Multivariable analysis demonstrates that the most significant independent risk factor for readmission is the occurrence of any postoperative complication (odds ratio = 4.20; 95% CI, 2.89-6.13). CONCLUSIONS Risk factors for readmission after general surgery procedures are multifactorial, however, postoperative complications appear to drive readmissions in surgical patients. Taking appropriate steps to minimize postoperative complications will decrease postoperative readmissions.

Resident Participation in Index Laparoscopic General Surgical Cases: Impact of the Learning Environment on Surgical Outcomes

BACKGROUND The NSQIP database enables measurement of postoperative outcomes across a spectrum of practice settings. This allows for observations about potential effects of resident participation in surgical care during training. STUDY DESIGN We queried the NSQIP database for 6 index laparoscopic surgical procedures performed during 2005-2008. Selected procedures require varying skill level (eg, appendectomy, cholecystectomy, gastric bypass, fundoplication, colectomy, and inguinal hernia), and 79,720 cases were identified. Preoperative, operative, and postoperative outcomes for each procedure were tabulated. Operative and postoperative outcomes assessed included operative time, hospital length of stay, mortality, morbidity, and return to the operating room. Initial analysis compared cases done with a resident present with cases done without residents. Subset analysis was done to determine possible differences in outcomes based on the level of resident participating, divided into Junior (PGY1-2), Senior (PGY3-5), or Fellow (PGY>5). Groups were scrutinized for both clinical and statistical differences. RESULTS Preoperative characteristics were similar between groups. Operative times were 20% to 47% longer with resident participation, with bigger differences seen in more basic procedures. Mortality and return to the operating room were not clinically different between the groups. Morbidity rates were higher in all procedures with resident participation. More senior residents were associated with longer operative times, without adverse impact on outcomes. CONCLUSIONS Resident participation increases operative times for laparoscopic surgery considerably. Morbidity is statistically higher with resident participation but differences are unlikely to be clinically significant. Resident participation is a surrogate for the learning environment. These findings provide impetus for additional development of training techniques that occur outside the operating room.

Urinary chemokines CXCL9 and CXCL10 are noninvasive markers of renal allograft rejection and BK viral infection.

Renal transplant recipients require periodic surveillance for immune‐based complications such as rejection and infection. Noninvasive monitoring methods are preferred, particularly for children, for whom invasive testing is problematic. We performed a cross‐sectional analysis of adult and pediatric transplant recipients to determine whether a urine‐based chemokine assay could noninvasively identify patients with rejection among other common clinical diagnoses. Urine was collected from 110 adults and 46 children with defined clinical conditions: healthy volunteers, stable renal transplant recipients, and recipients with clinical or subclinical acute rejection (AR) or BK infection (BKI), calcineurin inhibitor (CNI) toxicity or interstitial fibrosis (IFTA). Urine was analyzed using a solid‐phase bead‐array assay for the interferon gamma‐induced chemokines CXCL9 and CXCL10. We found that urine CXCL9 and CXCL10 were markedly elevated in adults and children experiencing either AR or BKI (p = 0.0002), but not in stable allograft recipients or recipients with CNI toxicity or IFTA. The sensitivity and specificity of these chemokine assays exceeded that of serum creatinine. Neither chemokine distinguished between AR and BKI. These data show that urine chemokine monitoring identifies patients with renal allograft inflammation. This assay may be useful for noninvasively distinguishing those allograft recipients requiring more intensive surveillance from those with benign clinical courses.

The impact of renal function on outcomes of bariatric surgery

The effect of CKD on the risks of bariatric surgery is not well understood. Using the American College of Surgeons National Surgical Quality Improvement Program Participant Use File, we analyzed 27,736 patients who underwent bariatric surgery from 2006 through 2008. Before surgery, 34 (0.12%) patients were undergoing long-term dialysis. Among those not undergoing dialysis, 20,806 patients (75.0%) had a normal estimated GFR or stage 1 CKD, 5011 (18.07%) had stage 2 CKD, 1734 (6.25%) had stage 3 CKD, 94 (0.34%) had stage 4 CKD, and 91 (0.33%) had stage 5 CKD. In an unadjusted analysis, CKD stage was directly associated with complication rate, ranging from 4.6% for those with stage 1 CKD or normal estimated GFR to 9.9% for those with stage 5 CKD (test for trend, P<0.001). Multivariable logistic regression demonstrated that CKD stage predicts higher complication rates (odds ratio for each higher CKD stage, 1.30) after adjustment for diabetes and hypertension. Although patients with higher CKD stage had higher complication rates, the absolute incidence of complications remained <10%. In conclusion, these data demonstrate higher risks of bariatric surgery among patients with worse renal function, but whether the potential benefits outweigh the risks in this population requires further study.

Endovascular Repair With Fenestrated-Branched Stent Grafts Improves 30-Day Outcomes for Complex Aortic Aneurysms Compared With Open Repair

BACKGROUND Endovascular repair is associated with better 30-day outcomes than open surgical repair for patients with infrarenal aortic aneurysms. In patients with complex aortic aneurysms (CAAs) requiring suprarenal or supravisceral aortic cross-clamping during open repair, few data exist directly comparing the real-world outcomes of open repair versus endovascular repair with fenestrated-branched stent grafts (FEVAR). METHODS Outcomes for patients who underwent elective CAA repair using open repair and FEVAR between 2005 and 2010 were analyzed using the American College of Surgeons National Surgical Quality Improvement Program database. CAA was defined as aneurysm of the aorta involving the visceral and/or renal arteries. RESULTS This study compared 1091 patients who underwent open repair (group A: male, 71.5%; age, 71 ± 9 years) with 264 patients treated with FEVAR (group B: male, 82.2%; age, 74 ± 9 years). The 2 groups did not significantly differ with respect to American Society of Anesthesiologists (ASA) classification (ASA III/IV: A, 93%; B, 95%, P = 0.6), severe chronic obstructive pulmonary disease (A: 21%; B: 22%; P = 0.7), prior cardiac surgery (A: 24%; B: 20%; P = 0.19), or preoperative renal function (glomerular filtration rate: A: 69 ± 2; B: 70 ± 27; P = 0.535). Group A had significantly higher risk of any complication (A: 42%; B: 19%; P < 0.001), nonsurgical complications (A: 30%; B: 8%; P < 0.001), pulmonary complications (A: 21%; B: 2%; P < 0.001), renal complications (A: 10%; B: 1.5%; P = 0.001), and any cardiovascular complication (A: 8%; B: 2%; P < 0.001). The composite end point of surgical site infections/graft failure/bleeding transfusions were also higher in group A (A: 22%; B: 15%; P = 0.014). Thirty-day mortality was significantly lower for FEVAR (A: 5.4%; B: 0.8%; P = 0.001), as was total length of hospital stay (A: 11 ± 10 days; B: 4 ± 5 days; P < 0.001). CONCLUSIONS This nationwide real-world database suggests that in similar patient populations, repair of CAAs with FEVAR is associated with reduced 30-day morbidity and mortality compared with open repair. Although long-term comparative studies are needed, FEVAR may represent a preferred treatment alternative to open repair for patients with CAAs.

Endovascular vs Open Repair of Renal Artery Aneurysms: Outcomes of Repair and Long-Term Renal Function

BACKGROUND Endovascular treatment (ER) of renal artery aneurysms (RAA) has been widely used recently due to its assumed lower morbidity and mortality compared with open surgery (OS). The purpose of this study was to investigate the outcomes of OS and ER, and compare long-term renal function. STUDY DESIGN Data from 2000 to 2012 were retrospectively collected to identify patients who were treated for RAA in a single institution. Morbidity, mortality, freedom from reinterventions, and renal function were compared between OS and ER for RAA. RESULTS Forty-four RAA repairs were identified in 40 patients (28 women, mean age ± SD 54 ± 13 years). Twenty RAA were repaired with OS (45%) and 24 RAA (55%) with ER. Mean aneurysm sizes were 2.5 ± 1.5 cm (OS) and 2.2 ± 2.2 cm (ER; p = 0.66). Endovascular repair included coil embolization with or without stent placement in 19 patients (79%) and stent grafts in 4 (17%). Open surgery included excision or aneurysmorrhaphy of the aneurysm in 11 kidneys (55%), graft interposition or bypass in 4 (20%), and 4 nephrectomies (20%). There was 1 technical failure in each group. Comorbidities were similar between the 2 groups (American Society of Anesthesiologists III-IV: OS, 40%; ER, 58%; p = 0.44). Endovascular repair and OR had equivalent perioperative morbidity (any complication OS, 15%, ER, 17%, p = 1.0) and no mortality (OS, 0%, ER, 0%). Endovascular repair was associated with shorter hospitalization (OS, 6.3 ± 2.5; ER, 2 ± 3.4 days, p < 0.001). Mean follow-ups were 21 ± 32 months (OS) and 27 ± 36 months (ER). A 30% reduction in glomerular filtration rate occurred in 12.5% of OS patients and 9.1% of ER patients (p = 1.00). Freedom from reintervention at 12 and 24 months were OS, 82%/82% and ER, 82%/74%, respectively (log-rank-test = 0.23). CONCLUSIONS Endovascular repair of RAA is as safe and effective as open repair in selected patients with appropriate anatomy. There was no difference in decline in renal function between OS and ER.

The allo- and viral-specific immunosuppressive effect of belatacept, but not tacrolimus, attenuates with progressive T cell maturation

Tacrolimus impairs allo‐ and viral‐specific T cell responses. Belatacept, a costimulation‐based alternative to tacrolimus, has emerged with a paradoxical picture of less complete control of alloimmunity with concomitant impaired viral immunity limited to viral‐naïve patients. To reconcile these signatures, bulk population and purified memory and naïve lymphocytes from cytomegalovirus (CMV)‐seropositive (n = 10) and CMV‐seronegative (n = 10) volunteers were studied using flow cytometry, interrogating proliferation (carboxyfluorescein succinimidyl ester dilution) and function (intracellular cytokine staining) in response to alloantigens or CMV‐pp‐65 peptides. As anticipated, T cells from CMV‐experienced, but not naïve, individuals responded to pp‐65 with a small percentage of their repertoire (<2.5%) consisting predominantly of mature, polyfunctional (expressing interferon gamma, tumor necrosis factor alpha and IL‐2) T effector memory cells. Both CMV naïve and experienced individuals responded similarly to alloantigen with a substantially larger percentage of the repertoire (up to 48.2%) containing proportionately fewer polyfunctional cells. Tacrolimus completely inhibited responses of CMV‐ and allo‐specific T cells regardless of their maturation. However, belatacepts effects were decreasingly evident in increasingly matured cells, with minimal effect on viral‐specific triple cytokine producers and CD28‐negative allo‐specific cells. These data indicate that belatacepts immunosuppressive effect, unlike tacrolimuss, wanes on progressively developed effector responses, and may explain the observed clinical effects of belatacept.

Laparoscopic Versus Open Appendectomy: An Analysis of Outcomes in 17,199 Patients Using ACS/NSQIP

BackgroundThe current study was undertaken to evaluate the outcomes for open and laparoscopic appendectomy using the 2008 American College of Surgeons: National Surgical Quality Improvement Program (ACS/NSQIP) Participant Use File (PUF). We hypothesized that laparoscopic appendectomy would have fewer infectious complications, superior perioperative outcomes, and decreased morbidity and mortality when compared to open appendectomy.Study DesignUsing the Current Procedural Technology (CPT) codes for open (44950) and laparoscopic (44970) appendectomy, 17, 199 patients were identified from the ACS/NSQIP PUF file that underwent appendectomy in 2008. Univariate analysis with chi-squared tests for categorical data and t tests or ANOVA tests for continuous data was used. Binary logistic regression models were used to evaluate outcomes for independent association by multivariable analysis.ResultsOf the patients, 3,025 underwent open appendectomy and 14,174 underwent laparoscopic appendectomy. Patients undergoing laparoscopic appendectomy had significantly shorter operative times and hospital length of stay. They also had a significantly lower incidence of superficial and deep surgical site infections, wound disruptions, fewer complications, and lower perioperative mortality when compared to patients undergoing open appendectomy.ConclusionsUsing the ACS/NSQIP PUF file, we demonstrate that laparoscopic appendectomy has better outcomes than open appendectomy for the treatment of appendicitis. While the operative treatment of appendicitis is surgeon specific, this study lends support to the laparoscopic approach for patients requiring appendectomy.

Age-Stratified Results from 20,095 Aortoiliac Aneurysm Repairs: Should We Approach Octogenarians and Nonagenarians Differently?

BACKGROUND In the endovascular era, elderly patients are offered repair of their aortoiliac aneurysms (AAA) more frequently than in the past. Our objective is to compare age groups and draw inferences for AAA repair outcomes. STUDY DESIGN We identified 20,095 patients who underwent AAA repair between 2005 and 2010 using the American College of Surgeons NSQIP national database. Preoperative characteristics and outcomes were compared among age groups (group A: 0 to 64 years; B: 65 to 79 years; C: 80 to 89 years; and D: 90 years and older). RESULTS The age distribution of the cohort was A: 17.1%, B: 57.2%, C: 24%, and D: 1.7%. Nonagenarians presented significantly more often as emergencies in comparison with groups A to C (A: 13.8%, B: 10.8%, C: 12.9%, D: 22.1%; p < 0.001). Endovascular aneurysm repair was performed more frequently in older patients (A: 55.2%, B: 63.7%, C: 74.6%, D: 77.9%; p < 0.001). Risk of any complication was significantly different among groups, becoming more prevalent with advanced age (A: 22.8%, B: 23.4%, C: 24.7%, D: 27.8%; p = 0.041). Nonsurgical complications (A: 14.7%, B: 16.4%, C: 18%, D: 19.8%; p < 0.001) and cardiovascular complications (A: 3.9%, B: 4.5%, C: 5.5%, D: 5.2%; p = 0.003) were also higher with advanced age. Overall mortality was 3.1%, 4.9%,7.2%, and 13.2% for groups A to D, respectively (p < 0.001). Mortality after elective AAA repair was significantly higher for open surgery compared with endovascular aneurysm repair in all age groups (open surgery vs endovascular aneurysm repair, A:1.9% vs 0.5%; p = 0.001; B: 3.9% vs 1.2%; p < 0.001; C: 7.4% vs 2%; p < 0.001; D: 18.8% vs 3.8%; p = 0.004). After adjusting for confounders in the entire cohort, advanced age persisted as an independent factor for postoperative mortality with a higher risk of death of 1.8 (95% CI, 1.3-2.5), 2.7 (95% CI, 1.9-3.8), and 3.3 (95% CI, 1.8-6.1) times for groups B, C, and D, respectively (group A reference). CONCLUSIONS Advanced age is independently associated with higher risk of death after AAA repair and indication for surgery should be adjusted for different age groups accordingly. Endovascular aneurysm repair should be preferred for octogenarians and nonagenarians with indication to undergo repair of their AAA.

Iliac Conduits for Endovascular Repair of Aortic Pathologies

OBJECTIVES Challenging iliac access during thoracic endovascular aortic repair (TEVAR) is associated with a higher risk of access site complications such as injury or rupture of the iliac vessels. As a result, the use of iliac conduits is frequently used to facilitate access during TEVAR. This report evaluates the effect of iliac conduits on TEVAR outcomes. METHODS The 2005-2010 American College of Surgeons Surgical Quality Improvement Program database was queried to identify vascular patients undergoing elective TEVAR. Patients without conduit (Group A) were compared to patients who underwent TEVAR with conduit (Group B). RESULTS We identified 1037 patients (90%) in Group A (69 ± 12.7 years, 42% female) and 117 patients (10%) in Group B (70 ± 12.6 years, 68% female). Women received conduits more often than men (Male:5.8%, Female:15.7%, p < 0.001). There was no significant difference in the rate of non-surgical (A:19%,B:25%,p = 0.121), pulmonary (A:11%,B:16%, p = 0.115), renal (A:3.1%, B:1.7%, p = 0.4) and cardiovascular complications (A:8%, B:12%, p = 0.143) between groups. However, any complication (A:24%, B:33%. p = 0.025), surgical complications (A:10%, B:16%, p = 0.035) and mortality (A:4.5%, B:12%. p = 0.001) were significantly higher in Group B. In multivariate analysis, use of conduit was associated with a 3.8 times higher risk of death compared with no conduit after controlling for confounders. Length of in-hospital stay was similar for both groups (A:6.6 ± 8.8, B:7.6 ± 8 days, p = 0.247). The use of conduits had a declining rate over time from 17.9% in 2006 down to 6.5% in 2010. CONCLUSIONS Female patients more frequently require iliac conduits during TEVAR compared to men. Conduits were associated with a higher rate of surgical complications and mortality. The incidence of conduit use has decreased threefold in the last five years. Safer access for TEVAR by use of a conduit should not be abandoned based on these results, but there should be a heightened awareness for the higher rate of mortality in these patients.