Nicholas A. Hamilton

A Multicenter Analysis of Distal Pancreatectomy for Adenocarcinoma: Is Laparoscopic Resection Appropriate?

BACKGROUND As compared with open distal pancreatectomy (ODP), laparoscopic distal pancreatectomy (LDP) affords improved perioperative outcomes. The role of LDP for patients with pancreatic ductal adenocarcinoma (PDAC) is not defined. STUDY DESIGN Records from patients undergoing distal pancreatectomy (DP) for PDAC from 2000 to 2008 from 9 academic medical centers were reviewed. Short-term (node harvest and margin status) and long-term (survival) cancer outcomes were assessed. A 3:1 matched analysis was performed for ODP and LDP cases using age, American Society of Anesthesiologists (ASA) class, and tumor size. RESULTS There were 212 patients who underwent DP for PDAC; 23 (11%) of these were approached laparoscopically. For all 212 patients, 56 (26%) had positive margins. The mean number of nodes (+/- SD) examined was 12.6 +/-8.4 and 114 patients (54%) had at least 1 positive node. Median overall survival was 16 months. In the matched analysis there were no significant differences in positive margin rates, number of nodes examined, number of patients with at least 1 positive node, or overall survival. Logistic regression for all 212 patients demonstrated that advanced age, larger tumors, positive margins, and node positive disease were independently associated with worse survival; however, method of resection (ODP vs. LDP) was not. Hospital stay was 2 days shorter in the matched comparison, which approached significance (LDP, 7.4 days vs. ODP, 9.4 days, p = 0.06). CONCLUSIONS LDP provides similar short- and long-term oncologic outcomes as compared with OD, with potentially shorter hospital stay. These results suggest that LDP is an acceptable approach for resection of PDAC of the left pancreas in selected patients.

Long-term results of resection of adenocarcinoma of the body and tail of the pancreas using radical antegrade modular pancreatosplenectomy procedure.

BACKGROUND The radical antegrade modular pancreatosplenectomy (RAMPS) procedure is a modification of standard distal pancreatosplenectomy. It was designed to provide the operative approach developed for cancers of the head of the pancreas to cancers of the body and tail of the pancreas, particularly with respect to the extent of node dissection and emphasis on obtaining microscopically negative tangential margins. The purpose of this report is to provide long-term survival results. STUDY DESIGN Forty-seven patients had RAMPS between 1999 and 2008. The decision to perform anterior vs posterior RAMPS was based on the position of the tumor as assessed by preoperative computed tomograms. Patients were entered in a prospective database and followed at intervals. RESULTS Thirty-two patients had anterior RAMPS and 15 had posterior RAMPS. Twenty-four patients had resection of 33 organs in addition to the left adrenal gland in the posterior RAMPS. Specimens were inked in the operating room. Mean tumor size was 4.4 cm. Negative tangential margins were obtained in 89% of specimens. Overall, the R0 rate was 81%. Mean lymph node count was 18. There were no 30-day or in-hospital mortalities. Mean and median follow-up times of living patients were 44.4 and 26.4 months. Median survival was 26 months and 5-year overall actuarial survival was 35.5%. The actual survival of 23 patients whose surgery was performed more than 5 years before the time of analysis was 30.4%. CONCLUSIONS RAMPS is associated with high negative tangential margin rates and very satisfactory survival rates for this aggressive tumor.

Comparison of WHO classifications (2004, 2010), the Hochwald grading system, and AJCC and ENETS staging systems in predicting prognosis in locoregional well-differentiated pancreatic neuroendocrine tumors

It is difficult to predict prognosis in patients with locoregional well-differentiated (WD) pancreatic neuroendocrine tumors (PanNET). We aimed to examine commonly used stratification systems [World Health organization (WHO) 2004 and 2010 classifications, American Joint Committee on Cancer (AJCC) and European Neuroendocrine Tumor Society (ENETS) staging, and the Hochwald grading system] for their power in predicting recurrence-free survival (RFS) in these patients. Seventy-five such patients (mean age 56 y, mean follow-up 79 mo) who underwent resection with sufficient tissue material and follow-up data were studied. RFS was correlated with variable clinicopathologic features and stratified with above-mentioned systems. Concordance index (CI) was then calculated. With the WHO 2004 classification, 16, 35, and 24 PanNETs were classified as benign behavior, uncertain behavior, and WD endocrine carcinoma, respectively. By the WHO 2010 classification, 26, 41, and 8 tumors were grade 1, 2, and 3, respectively. Using the Hochwald system, 47 were low grade, and 28 were intermediate grade. The AJCC staging information was complete for 62 patients (13 had the lymph node status Nx) and included: stages IA (19/62), IB (10/62), IIA (10/62), and IIB (23/62). The ENETS staging information was stages I (16/62), IIa (8/62), IIb (14/62), IIIa (0/62), and IIIb (24/62). The average Ki-67 proliferation index (PI) was 8.1%. Factors that predicted RFS included tumor size, nodal metastasis, vascular invasion, perineural invasion, necrosis, mitosis, and Ki-67 PI (all P<0.01). The CI for each system was: 0.6361 for WHO 2004, 0.6735 for WHO 2010, 0.6495 for AJCC staging, 0.6642 for ENETS staging, and 0.6851 for the Hochwald grading system. When these systems were analyzed in conjunction with various additional important pathologic features, combination of the Hochwald grading system and Ki-67 PI achieved the highest CI (0.7946). Therefore, although all these systems predict RFS well in locoregional WD PanNETs, the Hochwald grading system achieves the highest predictive ability. Further predictive power can be achieved by combining the Hochwald grading system and Ki-67 PI.

Mesh Reinforcement of Pancreatic Transection Decreases Incidence of Pancreatic Occlusion Failure for Left Pancreatectomy: A Single-Blinded, Randomized Controlled Trial

Introduction:Pancreatic leak or fistula is the most frequent complication after left pancreatectomy. We performed a single-blinded, parallel-group, randomized controlled trial comparing stapled left pancreatectomy with stapled left pancreatectomy using mesh reinforcement of the staple line with either Seamguard or Peristrips Dry. Methods:All patients undergoing left pancreatectomy at a large tertiary hospital were eligible for participation. Patients were randomized to either mesh reinforcement or no-mesh reinforcement intraoperatively after being determined a candidate for resection. Patients were blinded to the result of their randomization for 6 weeks. Primary outcome measure was clinically significant leak as defined by the ISGPF (International Study Group on Pancreatic Fistula) pancreatic leak grading system. Results:One hundred patients were randomized to either mesh (54) or no-mesh (46) reinforcement of their pancreatic transection. There was 1 death in each group. ISGPF grade B and C leaks were seen in 1.9% (1/53) of patients undergoing resection with mesh reinforcement and 20% (11/45) of patients without mesh reinforcement (P = .0007). Conclusions:Mesh reinforcement of pancreatic transection line significantly reduces the incidence of significant pancreatic fistula in patients undergoing left pancreatectomy. Trial Registration:Clinicaltrials.gov: NCT01359410

Laparoscopic versus open left pancreatectomy: can preoperative factors indicate the safer technique?

Background: Laparoscopic left pancreatectomy (LLP) is associated with favorable outcomes compared with open left pancreatectomy (OLP). However, it is unclear if the risk factors associated with operative morbidity differ between these two techniques. Guidelines for determining which patients should undergo OLP versus LLP do not exist. Methods: A multi-institutional analysis of OLP and LLP performed in 9 academic medical centers was undertaken. LLP cases were defined in an intent-to-treat manner. Perioperative variables were analyzed to identify factors associated with complications and pancreatic fistulae after OLP and LLP. In addition, complication and fistula rates for patients undergoing OLP and LLP were compared in matched cohorts to determine if one approach resulted in superior outcomes over the other. Results: Six hundred and ninety-three left pancreatectomy cases (439 OLP, 254 LLP) were analyzed. OLP and LLP cases were similar with respect to patient age and American Society of Anesthesiologists score. Body mass index (BMI) was higher in patients undergoing LLP. OLP was more often performed for adenocarcinoma and larger tumors, resulted in longer resected specimen lengths, and more commonly involved concomitant splenectomy. Estimated blood loss was higher and operative times were longer during OLP. On multivariate analysis, variables associated with major complications and clinically significant fistulae differed between OLP and LLP. Patients with body mass index ⩽27, without adenocarcinoma, and with pancreatic specimen length ⩽8.5 cm had significantly higher rates of significant fistulae after OLP than after LLP; in contrast, no preoperatively evaluable variables were associated with a higher likelihood of significant fistula after LLP versus OLP. Conclusions: Risk factors for complications and pancreatic fistulae after left pancreatectomy differ when open versus laparoscopic techniques are employed. Preoperative characteristics may identify cohorts of patients who will benefit more from LLP, and no patient cohorts had higher postoperative complication rates after LLP than OLP. These observations suggest that LLP may be the operative procedure of choice for most patients with left-sided pancreatic lesions; a more definitive prospective and randomized comparison may be warranted.

Ki-67 predicts disease recurrence and poor prognosis in pancreatic neuroendocrine neoplasms.

BACKGROUND Pancreatic neuroendocrine neoplasms are rare malignancies for which the ideal staging method remains controversial. Ki-67 is a cell proliferation marker that has been shown to have some utility in predicting prognosis in neuroendocrine neoplasms. We sought to test the predictive ability of Ki-67 staining for disease recurrence and overall survival (OS) in pancreatic neuroendocrine neoplasms. METHODS The medical records of patients who underwent pancreatic resection for pancreatic neuroendocrine neoplasms at a tertiary referral hospital from 1994 to 2009 were reviewed. The pathologic specimens of all were stained for Ki-67 and recorded as percentage of cells staining positive per high-powered field. The 10-year disease-free and OSs were analyzed. RESULTS We identified 140 patients. Gender and age were not associated with increased risk of disease recurrence. Patients with tumors >4 cm or with Ki-67 staining >9% were more likely to have disease recurrence (P = .0454 and .047) and have decreased OS (P < .0001 and .0007). CONCLUSION Increasing tumor size and increasing Ki-67 staining both correlate with increased risk of disease recurrence and decreased OS. Designing a staging system that incorporates both of these clinical variables will enable better identification of patients at risk for recurrent pancreatic neuroendocrine neoplasms.

Video Review Using a Reliable Evaluation Metric Improves Team Function in High-Fidelity Simulated Trauma Resuscitation

OBJECTIVE To demonstrate that instruction of proper team function can occur using high-fidelity simulated trauma resuscitation with video-assisted debriefing and that this process can be integrated rapidly into a standard general surgery curriculum. DESIGN The rater reliability of our team metric was assessed by having physicians and nonphysicians rate the same video-recorded trauma simulations at intervals in time. To assess the effectiveness of video debriefing, subjects participated in a 3-week trauma team training course that consisted of 2 video-recorded simulation sessions, each approximately 2 hours in length separated by a 90-minute debriefing session. To assess the impact of the debriefing session, video recordings of participants performing resuscitations before and after the debriefing were reviewed by a panel of blinded traumatologists and graded using our team evaluation instrument. SETTING The study took place at the high-fidelity simulation center at a large, urban academic training hospital. PARTICIPANTS All 11 PGY-2 general surgery and combined general surgery and plastic surgery residents at our institution. RESULTS Our instrument was found to have high interrater correlation (interclass correlation coefficient [ICC], 0.926; 95% confidence interval, 0.893-0.953). Initially, residents were either unsure as to their competency to serve as team leader (70%) or felt they were not competent to serve as team leader (30%). Ninety percent of residents found the video debriefing very to extremely helpful in improving team function and clinical competency. All participants felt more competent as both team leaders and team members because of the video debriefing. The mean team function score improved significantly after video debriefing (4.39 [±0.3] vs 5.45 [±0.4] prevideo vs postvideo review, p < 0.05). CONCLUSIONS Video review with debriefing is an effective means of teaching team competencies and improving team function in simulated trauma resuscitation. This strategy can be integrated readily into the surgical curriculum analogous to other applications of simulation technology.

Risk Factors and Outcomes of Surgical Site Infection in Children

BACKGROUND Indices for prediction of surgical site infection (SSI) are well documented in the adult population; however, these factors have not been validated in children. STUDY DESIGN A retrospective case-control study was performed by examining the medical records of children (0 to 18 years) who developed an SSI within 30 days of selected class I and class II procedures at our institution from 1996 to 2008. Two controls were selected from among patients undergoing identical procedures within 12 months of each case. Statistical analysis was performed using Wilcoxon test for continuous and chi-square test for categorical variable. Factors thought a priori to be associated with risk of SSI and statistically significant variables from a univariate analysis were used to create a logistic regression model. RESULTS Of 16,031 patients, 159 children (0.99%) developed an SSI. Univariate analysis showed race, postoperative location, skin preparation, urinary catheter, procedure duration, and implantable device as risk factors for development of an SSI. Independent predictors of SSI in multiple conditional logistic regression were age (adjusted odds ratio [aOR] 4.97 neonate vs adolescent; 95% CI 1.38 to 17.90), race (aOR 2.36 for African American vs white; 95% CI 1.32 to 4.18), postoperative location (aOR 6.55 ICU vs home; 95% CI 1.58 to 27.21), urinary catheter placement (aOR 3.56; 95% CI 1.50 to 8.48), and implantable device (aOR 3.05; 95% CI 1.14 to 8.21). Wound classification and antibiotic administration were not independent predictors of SSI. CONCLUSIONS Postoperative location, urinary catheter insertion, and use of an implantable device are potentially modifiable risk factors for an SSI in children. The higher risk of SSI in younger patients and non-white race suggest a possible developmental, socioeconomic, or genetic marker for impaired host defense.

Team Behavior During Trauma Resuscitation: A Simulation-Based Performance Assessment

INTRODUCTION Trauma resuscitations require a coordinated response from a diverse group of health care providers. Currently, there are no widely accepted methods of assessing team effectiveness in this setting. Simulation affords a method to assess team effectiveness. The purpose of this study was to use a simulation setting to develop a specialized assessment instrument for team response in trauma resuscitation. METHODS We developed our assessment instrument using clinical simulation. Four teams of 3 postgraduate year-2 surgical trainees in conjunction with scripted confederates were videotaped enacting 6 separate trauma resuscitation scenarios that mirrored clinical conditions encountered at our level 1 trauma center. Ten of the resulting videotaped scenarios represented a spectrum of team behavior (ineffective to effective) and were scored by 8 experienced clinicians using the Mayo High Performance Teamwork Scale. RESULTS Based in part on the Mayo High Performance Teamwork Scale, we created a prototype trauma team assessment tool consisting of 7 attributes that we scored in binary fashion (present/absent). We validated this prototype by assigning a normalized ranking score to each of the 10 scenarios based on the score supplied by each rater. The presence/absence of the 7 attributes varied significantly among scenarios (52.5% to 93.8%; P < .001). Median scores differed significantly comparing the 5 lowest-ranking scenarios with the 5 highest-ranking scenarios (P < .001). CONCLUSION Our prototype instrument may be effective at assessing team effectiveness during trauma resuscitations. This instrument may prove useful for assessing team competency skills, providing timely feedback to teams, and examining the relationship between effective team function and clinically important outcomes. Further, it may be applicable to other high-acuity, time-sensitive clinical situations.

The effect of mesh reinforcement of a stapled transection line on the rate of pancreatic occlusion failure after distal pancreatectomy: review of a single institution's experience

BACKGROUND Pancreatic occlusion failure (POF) after distal pancreatectomy remains a common source of morbidity. Here, we review our experience with distal pancreatectomy and attempt to identify factors which influence POF rates. PATIENTS AND METHODS One hundred sixty-nine distal pancreatectomies were performed between 2002 and 2007. Review of the computerized medical records and physician office records was performed for all patients. Univariate and multivariate analyses were performed to determine factors which might influence the incidence of POF. The data set was analysed for factors which might influence the pancreatic occlusion rate. Analysis included patient and disease characteristics including: age, gender, body mass index (BMI), diagnosis, consistency of the pancreas and history of pancreatitis, as well as intra-operative variables including: surgeon, absorbable mesh reinforcement and operative approach. RESULTS POF was the most common peri-operative complication. POF was identified in 32 out of 169 patients (19%). Transection technique (hand sewn, stapled, stapled with mesh) and procedure complexity were factors associated with differences in POF rates by both univariate and multivariate analyses. POF was identified in 7 out of 70 patients (10%) when an absorbable mesh was utilized, and 25 of 99 patients (25%) when mesh was not utilized (P < 0.02). DISCUSSION These data suggest that a randomized controlled trial will be required to determine if mesh reinforcement reduces the rate and severity of POF after distal pancreatectomy.