Jan Grendar

Negative-pressure wound therapy for critically ill adults with open abdominal wounds: A systematic review

BACKGROUND Open abdominal management with negative-pressure wound therapy (NPWT) is increasingly used for critically ill trauma and surgery patients. We sought to determine the comparative efficacy and safety of NPWT versus alternate temporary abdominal closure (TAC) techniques in critically ill adults with open abdominal wounds. METHODS We conducted a systematic review of published and unpublished comparative studies. We searched MEDLINE, PubMed, EMBASE, Scopus, Web of Science, the Cochrane Database, the Center for Reviews and Dissemination, clinical trials registries, and bibliographies of included articles. Two authors independently abstracted data on study design, methodological quality, patient characteristics, and outcomes. RESULTS Among 2,715 citations identified, 2 randomized controlled trials and 9 cohort studies (3 prospective/6 retrospective) met inclusion criteria. Methodological quality of included prospective studies was moderate. One randomized controlled trial observed an improved fascial closure rate (relative risk [RR], 2.4; 95% confidence interval [CI], 1.0–5.3) and length of hospital stay after addition of retention sutured sequential fascial closure to the Kinetic Concepts Inc. (KCI) vacuum-assisted closure (VAC). Another reported a trend toward enhanced fascial closure using the KCI VAC versus Barker’s vacuum pack (RR, 2.6; 95% CI, 0.95–7.1). A prospective cohort study observed improved mortality (RR, 0.48; 95% CI, 0.25–0.92) and fascial closure (RR, 1.5; 95% CI, 1.1–2.0) for patients who received the ABThera versus Barker’s vacuum pack. Another noted a reduced arterial lactate, intra-abdominal pressure, and hospital stay for those fitted with the KCI VAC versus Bogotá bag. Most included retrospective studies exhibited low methodological quality and reported no mortality or fascial closure benefit for NPWT. CONCLUSION Limited prospective comparative data suggests that NPWT versus alternate TAC techniques may be linked with improved outcomes. However, the clinical heterogeneity and quality of available studies preclude definitive conclusions regarding the preferential use of NPWT over alternate TAC techniques. LEVEL OF EVIDENCE Systematic review, level III.

Predicting In-Hospital Mortality in Patients Undergoing Complex Gastrointestinal Surgery: Determining the Optimal Risk Adjustment Method

OBJECTIVE To compare the performance of Charlson/Deyo, Elixhauser, Disease Staging, and All Patient Refined Diagnosis-Related Groups (APR-DRGs) algorithms for predicting in-hospital mortality after 3 types of major abdominal surgeries: gastric, hepatic, and pancreatic resections. DESIGN Cross-sectional nationwide sample. SETTING Nationwide Inpatient Sample from 2002 to 2007. PATIENTS Adult patients (≥18 years) hospitalized with a primary or secondary procedure of gastric, hepatic, or pancreatic resection between 2002 and 2007. MAIN OUTCOME MEASURES Predicting in-hospital mortality using the 4 comorbidity algorithms. Logistic regression analyses were used and C statistics were calculated to assess the performance of the indexes. Risk adjustment methods were then compared. RESULTS In our study, we identified 46,395 gastric resections, 18,234 hepatic resections, and 15,443 pancreatic resections. Predicted in-hospital mortality rates according to the adjustment methods agreed for 43.8% to 74.6% of patients. In all types of resections, the APR-DRGs and Disease Staging algorithms predicted in-hospital mortality better than the Charlson/Deyo and Elixhauser indexes (P < .001). Compared with the Charlson/Deyo algorithm, the Elixhauser index was of higher accuracy in gastric resections (0.847 vs 0.792), hepatic resections (0.810 vs 0.757), and pancreatic resections (0.811 vs 0.741) (P < .001 for all comparisons). Higher accuracy of the Elixhauser algorithm compared with the Charlson/Deyo algorithm was not affected by diagnosis rank, multiple surgeries, or exclusion of transplant patients. CONCLUSIONS Different comorbidity algorithms were validated in the surgical setting. The Disease Staging and APR-DRGs algorithms were highly accurate. For commonly used algorithms such as Charlson/Deyo and Elixhauser, the latter showed higher accuracy.

Effect of N‐acetylcysteine on liver recovery after resection: A randomized clinical trial

Liver failure following hepatic resection is a multifactorial complication. In experimental studies, infusion of N‐acetylcysteine (NAC) can minimize hepatic parenchymal injury.

Novel Simulation Device for Targeting Tumors in Laparoscopic Ablation: A Learning Curve Study

Introduction. A novel 3-dimensional (3D) guidance system was developed to aid accurate needle placement during ablation. Methods. Five novices and 5 experienced hepatobiliary surgeons were recruited. Using an agar block with analog tumor, participants targeted under 4 conditions: in-line with the ultrasound plane using ultrasound, in-line using 3D guidance, 45° off-axis using ultrasound, and off-axis using 3D guidance. Time to target the tumor, number of withdrawals, and the National Aeronautics and Space Administration Task Load Index were collected. Initial and final parameters for each of the conditions were compared using a within-subjects paired t test. Results. A significant reduction was seen in the number of required withdrawals in all situations when using the 3D guidance (0.75 vs 3.65 in-line and 0.25 vs 3.6 for off-axis). Mental workload was significantly lower when using 3D guidance compared with ultrasound both for novices (29.85 vs 41.03) and experts (31.98 vs 44.57), P < .001 for both. The only difference in targeting time between first and last attempt was in the novice group during off-axis targeting using 3D guidance (115 vs 32.6 seconds, P = .03). Conclusion. Though 3D guidance appeared to decrease time to target, this was not statistically significant likely as a result of lack of power in our trial. Three-dimensional guidance did reduce the number of required withdrawals, potentially decreasing complications, as well as mental workload after proficiency was achieved. Furthermore, novices without experience in ultrasound were able to learn targeting with the 3D guidance system at a faster pace than targeting with ultrasound alone.

Regional Metastatic Behavior of Nonfunctional Pancreatic Neuroendocrine Tumors: Impact of Lymph Node Positivity on Survival

Objectives Literature addressing the significance of lymph node positivity in the management of nonfunctional pancreatic neuroendocrine tumors (PNETs) is conflicting. Methods The National Cancer Data Base was queried for patients who underwent surgical resection of nonfunctional PNETs between 1998 and 2011. Clinical data and overall survival were analyzed using &khgr;2 and Cox proportional hazards regression. Multiple imputation was used as a comparative analysis because of the high number of patients missing data on tumor grade. Results Two thousand seven hundred thirty-five patients were identified. The overall incidence of lymph node metastasis was 51%. In the subset of patients with grade 1 tumors less than 1 cm, 24% had positive lymph nodes. Overall median survival for patients with negative lymph nodes was 11 years compared with 8 years for lymph node–positive patients (P < 0.001). On multivariate survival analysis, tumor grade, distant metastases, regional lymph node involvement, positive surgical margins, male sex, and older age were predictive of decreased overall survival. Conclusions Lymph node positivity was associated with decreased overall survival. The incidence of lymph node involvement in resected low-grade tumors less than 1 cm is higher than previously reported. Patients selected for resection of PNETs should be offered lymphadenectomy for staging.

Minimally Invasive Pancreas Resections

The technical complexity and associated high complication rate initially hindered the adoption of minimally invasive approaches to pancreatic surgery. Improvements in technology and increasing surgeon experience slowly over came this hesitancy. Over the last decade, successful minimally invasive approaches to essentially all types of pancreatic surgery have been described. The best results are reported from high volume programs with teams dedicated to developing and performing these procedures. We describe the current state of the literature, as well as our techniques for performing these procedures. We caution the reader that acceptable outcomes have been highly associated with proper training, experience, and volumes.

Reply to “Analysis of 340 Patients with Solid Pseudopapillary Tumors of the Pancreas: A Closer Look at Patients with Metastatic Disease; Methodologic Issues,” by Safiri, Saeid et al.

Dear Editor-in-Chief: We thank the authors Ayubi and Safiri for their thorough review of our study and their thoughtful comments. We hope the following reply answers the questions raised in their letter. First, at completion of the univariate analysis as per Hosmer–Lemeshow recommendations, we selected variables for the multivariate analysis with p values lower than 0.25 together with variables of known clinical importance. Then backward elimination was used to arrive at the final model, with variables considered significant if they had p values lower than 0.05. That process allowed us to avoid the ‘‘testimation’’ bias, with only predictors having relatively large effects included. Second, we did not report all the nonsignificant p values because this is not a standard reporting requirement, although we appreciate comments about reporting exact p values even when nonsignificant. Third, during the model-building process, the predictors were examined for possible multicollinearity or high correlation. Collinearity often is manifested by large estimated errors and sometimes by a large estimated coefficient as well (H-S). This finding was not observed in our model and not reported, although the subject was discussed during the review process of our manuscript. Finally, after the final mode of significant explanatory variables was created, we validated the proportional hazards assumption. We conclude that the proportional hazards assumption holds. Furthermore, the graphic display of the risk-adjusted survival curves is parallel (Fig. 1). Due to the limitation concerning the number of figures that can be published, we did not include this in our original manuscript. We appreciate the authors’ interest in the methodologic reporting of our manuscript.

Response to Letter to the Editor on “Effect of N-acetylcysteine on liver recovery after resection. A randomized clinical trial”

Dear Editor, We would like to thank Drs. Mohamed, Krishnakumar, and Sudhindran for their insightful comments on our trial [1] and their experiences with N-acetylcysteine. They describe their institutional observations of much lower rates of postoperative delirium in patients undergoing donor hepatectomies who receive NAC (0.5% vs. 9% of resections in our study). We agree with their hypotheses regarding possible differences and discrepancies. Indeed, it is possible that coding of hepatic or septic encephalopathy and delirium in studies is not completely separated, resulting in possible reporting differences. It is important to mention again the symptomatology of delirious patients receiving NAC in our study. All patients developed symptoms early, septic work up and liver functions assessments were performed and subsequently infusion was stopped. Resolution of delirium then rapidly followed discontinuation of infusion (usually within hours). We also mentioned in our manuscript, and would like to stress again, that all observations and diagnoses were made by treating surgeons in a nonblinded study. Although dosing may influence occurrence of side effects, we do not think that minor differences in dosing are significant in terms of being the cause of delirium. There is a report of cerebral dysfunction that started with delirium and resulted in patient’s death with massive overdose of NAC [2]. But in that case the incidentally delivered dose exceeds the intended dose 16 times. It was interesting to learn how commonly NAC is being used in living donor hepatectomies. In that case, we absolutely agree with a multicenter trial assessing the role of NAC in that patient population. Thank you very much for your very relevant comments and suggestions.

Circulating immune cells in patients with surgically resected nonfunctional pancreatic neuroendocrine tumors

Background There is debate regarding whether surgical resection and/or lymphadenectomy are indicated for small nonfunctional pancreatic neuroendocrine tumors (PNETs). Myeloid cell population expansion in peripheral blood has been correlated with clinical stage of patients with solid tumors. We aim to determine if blood sampling can be used as a predictor of malignant potential in nonfunctional PNETs.