Daniel A. Anaya

Necrotizing Soft-Tissue Infection: Diagnosis and Management

Necrotizing soft-tissue infections (NSTIs) are highly lethal. They are frequent enough that general and specialty physicians will likely have to be involved with the management of at least 1 patient with NSTI during their practice, but they are infrequent enough that familiarity with the disease will seldom be achieved. Establishing the diagnosis of NSTI can be the main challenge in treating patients with NSTI, and knowledge of all available tools is key for early and accurate diagnosis. The laboratory risk indicator for necrotizing fasciitis score can be helpful for distinguishing between cases of cellulitis, which should respond to medical management alone, and NSTI, which requires operative debridement in addition to antimicrobial therapy. Imaging studies are less helpful. The mainstay of treatment is early and complete surgical debridement, combined with antimicrobial therapy, close monitoring, and physiologic support. Novel therapeutic strategies, including hyperbaric oxygen and intravenous immunoglobulin, have been described, but their effect is controversial. Identification of patients at high risk of mortality is essential for selection of patients that may benefit from future novel treatments and for development and comparison of future trials.

Outcome Prediction in Primary Resected Retroperitoneal Soft Tissue Sarcoma: Histology-Specific Overall Survival and Disease-Free Survival Nomograms Built on Major Sarcoma Center Data Sets

PURPOSE Integration of numerous prognostic variables not included in the conventional staging of retroperitoneal soft tissue sarcomas (RPS) is essential in providing effective treatment. The purpose of this study was to build a specific nomogram for predicting postoperative overall survival (OS) and disease-free survival (DFS) in patients with primary RPS. PATIENTS AND METHODS Data registered in three institutional prospective sarcoma databases were used. We included patients with primary localized RPS resected between 1999 and 2009. Univariate (Kaplan and Meier plots) and multivariate (Cox model) analyses were carried out. The a priori chosen prognostic covariates were age, tumor size, grade, histologic subtype, multifocality, quality of surgery, and radiation therapy. External validation was performed by applying the nomograms to the patients of an external cohort. The models discriminative ability was estimated by means of the bootstrap-corrected Harrell C statistic. RESULTS In all, 523 patients were identified at the three institutions (developing set). At a median follow-up of 45 months (interquartile range, 22 to 72 months), 171 deaths were recorded. Five- and 7-year OS rates were 56.8% (95% CI, 51.4% to 62.6%) and 46.7% (95% CI, 39.9% to 54.6%. Two hundred twenty-one patients had disease recurrence. Five- and 7-year DFS rates were 39.4% (95% CI, 34.5% to 45.0%) and 35.7% (95% CI, 30.3% to 42.1%). The validation set consisted of 135 patients who were identified at the fourth institution for external validation. The bootstrap-corrected Harrell C statistics for OS and DFS were 0.74 and 0.71 in the developing set and 0.68 and 0.69 in the validating set. CONCLUSION These nomograms accurately predict OS and DFS. They should be used for patient counseling in clinical practice and stratification in clinical trials.

Infectious postoperative complications decrease long-term survival in patients undergoing curative surgery for colorectal cancer: a study of 12,075 patients.

OBJECTIVE We sought to characterize the effect of postoperative complications on long-term survival after colorectal cancer (CRC) resection. BACKGROUND The impact of early morbidity on long-term survival after curative-intent CRC surgery remains controversial. METHODS The Veterans Affairs Surgical Quality Improvement Program and Central Cancer Registry databases were linked to acquire perioperative and cancer-specific data for 12,075 patients undergoing resection for nonmetastatic CRC (1999-2009). Patients were categorized by presence of any complication within 30 days and by type of complication (noninfectious vs infectious). Univariate and multivariate survival analyses adjusted for patient, disease, and treatment factors were performed, excluding early deaths (<90 days). Subset analysis was performed to determine the specific impact of severe postoperative infections. RESULTS The overall morbidity and infectious complication rates were 27.8% and 22.5%, respectively. Patients with noninfectious postoperative complications were older, had lower preoperative serum albumin, had worse functional status, and had higher American Society of Anesthesiologists scores than patients with infectious complications and without complications (all P < 0.001). The presence of any complication was independently associated with decreased long-term survival [hazard ratio, 1.24; 95% confidence interval (1.15-1.34)]. Multivariate analysis by complication type demonstrated increased risk only with infectious complications [hazard ratio, 1.31; 95% confidence interval (1.21-1.42)]. Subset analysis demonstrated this effect predominantly in patients with severe infections [hazard ratio, 1.41; 95% confidence interval (1.15-1.73)]. CONCLUSIONS The presence of postoperative complications after CRC resection is associated with decreased long-term survival, independent of patient, disease, and treatment factors. The impact on long-term outcome is primarily driven by infectious complications, particularly severe postoperative infections.

Hartmann's colectomy and reversal in diverticulitis: a population-level assessment.

PURPOSEThis study was designed to assess the costs and outcomes of colostomy and colostomy reversal in patients with diverticulitis and examine the impact of such procedures on the health care system.METHODSWe employed a retrospective design and used a Washington State administrative database to identify patients undergoing operations with colostomy (1987–2002) who were followed over time. Descriptive and comparative analysis was performed, focusing on patients with diverticulitis.RESULTSThere were 16,556 patients who underwent colostomy and 5,420 (32.7 percent) were for diverticulitis and its related complications (mean age, 64.8 ± 15.1 years; 53.2 percent female). In patients with diverticulitis, the rate of colostomy reversal was 56.3 percent (80 percent in patients less than 50 years, and 30 percent in patients over 77 years). The in-hospital mortality rate after colostomy reversal was 0.36 percent, and was 2.6 percent in those over 77 years of age. After colostomy reversal a second stoma was used in 3.4 percent, reoperation was required for bleeding complications in 0.6 percent, and infectious complications were noted in 2 percent. The length of time from colostomy to its reversal was approximately five months (138.1 ± 164 days; interquartile range, 72–156). The relationship between the length of time from colostomy to reversal was evaluated and the adjusted odds of a second stoma being used at the time of colostomy reversal were 45 percent higher (odds ratio, 1.45; 95 percent confidence interval, 1.22, 1.73) for each increase in time interval (<3, 6–9, 9–12, >12 months).CONCLUSIONSOne-third of all colostomies were related to diverticulitis and only 56 percent were reversed. We identified a higher than expected mortality rate among older patients undergoing colostomy reversal. The impact of colostomy and reversal operations on both patients and the health care system is significant.

Infectious and immunologic consequences of blood transfusion.

Blood transfusions remain common practice in the critical care and surgical settings. Transfusions carry significant risks, including risks for transmission of infectious agents and immune suppression. Transmission of bacterial infections, although rare, is the most common adverse event with transfusion. The risk for transmission of viral infections has decreased over time, clearly because tests are becoming more sensitive in detecting certain viral infections such as hepatitis B, hepatitis C, and HIV. Several immunomodulatory effects are thought to be related to transfusions, and these can result in cancer recurrence, mortality, and postoperative infections. Numerous studies have been performed to examine the role of leukoreduction in decreasing these transfusion-related complications but results remain contradictory. We review the infectious risks associated with blood transfusion and the most recent data on its immunologic effects, specifically on cancer recurrence, mortality, and postoperative infections in surgical patients. We also review the use of leukoreduction in blood transfusion and its role in preventing transfusion-transmitted infections and immunomodulatory complications.

Risk Factors for Severe Sepsis in Secondary Peritonitis

BACKGROUND The incidence and risk factors for severe sepsis (SS, organ failure associated with infection) in the context of peritonitis are not well established; thus, it is not clear which patients require more aggressive operative or pharmacologic intervention. We set out to determine risk factors for severe sepsis in a large cohort of patients with intra-abdominal infection. METHODS Patients admitted for peritonitis over a four-year interval were identified using a Washington State administrative hospital discharge database. This cohort was identified by ICD-9 CM diagnoses and diagnosis-related group (DRG) assignment. Patients with organ failure were identified by ICD-9 CM diagnoses codes using a previously validated classification scheme. Independent risk factors for SS were identified using stepwise Poisson regression. RESULTS A total of 11,202 patients with peritonitis were identified, 11% of whom developed SS. The crude relative risk of death in patients with SS was 13 (95% CI, 11.1-15.2) times greater than those without. Severe sepsis was present in 424 (62%) of the 686 decedents. Multivariate analysis showed that source of infection, extent of peritonitis, increasing age, and pre-existing organ dysfunction were independently associated with SS. CONCLUSIONS Severe sepsis complicates the course of 11% of all patients with peritonitis. Risk factor analysis identifies a subset of patients at greatest risk for severe sepsis. These are the patients who should be targeted for evaluation of novel pharmacologic interventions or more aggressive surgical intervention.

Shifting trends in liver-directed management of patients with colorectal liver metastasis: A population-based analysis

BACKGROUND We sought to evaluate population-based temporal trends in perioperative management, as well as short- and long-term outcomes associated with the operative management of colorectal liver metastasis (CRLM). METHODS Using Surveillance, Epidemiology and End Results-Medicare linked data, we identified 2,121 patients with operatively managed CRLM between 1991 and 2006. Clinicopathologic data, trends in operative management, and survival were examined. RESULTS Preoperative evaluation included computed tomography (CT; 66%), magnetic resonance imaging (MRI; 5%), and positron emission tomography (PET; 2%) with a temporal increase in the use of all 3 modalities over time (all P < .05). Patients undergoing hepatectomy only (n = 1,267; 60%) decreased over time, whereas the use of ablation alone (n = 668; 32%) and combined resection plus ablation (n = 186; 9%) increased (all P < .05). The use of both preoperative (10% to 16%) and adjuvant chemotherapy (35% to 47%) increased over time (P < .05). There was a marked temporal increase in patient comorbidities (>3 comorbidities: 1991-1995, 3%; 2003-2006, 12%; P < .001); however, perioperative complications (63%) and 30-day mortality (3%) did not change over time (both P > .05); 90-day mortality decreased from 9% to 7% over the study period (P = .007). Overall the 1-, 3-, and 5-year survivals were 74%, 42%, and 28% with no improvement over time (P = .19). On multivariate analysis, synchronous disease (hazard ratio [HR], 1.7) and use of ablation alone (HR, 1.2) were associated independently with a worse survival (both P < .05). CONCLUSION Most patients were evaluated with CT; PET was employed rarely. Although there was a temporal increase in chemotherapy utilization, only one half of patients received perioperative chemotherapy. Mortality associated with hepatic operations was low, but morbidity remained high with no temporal change despite an increased number of patient medical comorbidities.

Obesity increases wound complications in rectal cancer surgery

BACKGROUND Obesity increases the risk of wound infections following surgery for colon cancer. Considerably less data is available, however, regarding the impact of obesity on infections and wound complications after resection for rectal cancer. Additionally, the impact of minimally invasive surgery (MIS) on complications in rectal surgery remains unclear. We hypothesized that obesity is associated with prolonged operative time and more infectious complications in obese patients undergoing both MIS and open surgery for rectal cancer. MATERIALS AND METHODS Review of retrospective surgical database. RESULTS One hundred fifty patients underwent surgery for rectal cancer from 2002 to 2009. Open cases accounted for 72% (n = 108) and MIS for 28% (n = 42) of cases. BMI did not correlate with increased operative time in open rectal surgery, but in MIS patients, operative time increased from a median of 254 min in the lowest quartile of BMI to 333 min in the highest quartile (P < 0.004). Superficial wound infections in open rectal surgery increased from 17% to 52% with increasing BMI (P < 0.005). The increased rate of wound complications persisted in the MIS group. Rate of superficial wound infections and subsequent open packing in the MIS group increased from 0% in the lowest BMI quartile to 33% in the highest quartile (P < 0.029 and P < 0.007, respectively). CONCLUSIONS Elevated BMI is associated with increased wound complications in both minimally invasive and open rectal surgery. This trend may be related to prolonged operative time in obese patients, particularly in MIS. Our observations suggest that more aggressive techniques to prevent infection are warranted in obese patients undergoing rectal surgery.

Predicting Death in Necrotizing Soft Tissue Infections: A Clinical Score

BACKGROUND Necrotizing soft tissue infections (NSTIs) are associated with a high mortality rate; however, there is no uniform way to categorize the severity of this disease early in its course. The goal of this study was to develop a clinical score based on data available at the time of initial assessment to aid in stratifying patients according to their risk of death. METHODS A cohort of all 350 patients admitted with NSTI to two institutions over a nine-year period was examined retrospectively. Using random split sampling, two datasets were created: Prediction (PD) and validation (VD). Multivariable stepwise regression analysis of the PD identified independent predictors of death using data available at the time of admission. Model performance was evaluated for accuracy, discrimination, and calibration. A clinical score to predict death was created, and using the Trauma and Injury Severity Score (TRISS) methodology, the score was validated on the VD (z-statistic). RESULTS Six admission parameters independently predicted death: Age > 50 years, heart rate > 110 beats/min, temperature <36 degrees C, white blood cell count > 40,000/mcL, serum creatinine concentration > 1.5 mg/dL, and hematocrit > 50%. The accuracy of this model was 86.8%; the area under the receiver-operating characteristic curve was 0.81, and the Hosmer-Lemeshow statistic was 11.8. Additionally, the score had excellent performance in evaluation on the VD (z-score/statistic 0.23 to - 0.83). CONCLUSION A clinical score that categorizes patients with NSTI according to the risk of death was created. It uses simple variables, all available at the time of first assessment. It stratifies patients according to disease severity and can guide the use of aggressive or novel therapeutic strategies and selection of patients for clinical trials.

Global graying, colorectal cancer and liver metastasis: New implications for surgical management

Aging of the population - global graying - is occurring rapidly, with significant effects on epidemiology, treatment and outcomes for cancer patients. In colorectal cancer, outcomes for the elderly are worse than those for younger patients, partially driven by treatment disparities between the two groups. Nonetheless, standard-of-care treatment for the elderly results in equivalent long-term outcomes to those observed in the younger population; and available data support the use of aggressive surgery and adjuvant therapies in well-selected patients. Data evaluating epidemiology, treatment patterns and outcomes in elderly patients with colorectal cancer liver metastasis are lacking. Liver resection offers the only curative approach, but it is rarely offered to older adults. Current data support the use of hepatectomy for well-selected elderly colorectal cancer patients with liver metastasis; however, this and other evolving therapies need to be assessed in the elderly to better define their role, indications, safety and outcomes.