The Effect of Commonly Used Local Anesthetic on Bacterial Growth.

INTRODUCTION: Liposomal bupivacaine (LB) has emerged as a superior form of local anesthetic across numerous surgical subspecialties. The purpose of this study is to evaluate the ex-vivo antimicrobial effects of LB in comparison with traditional local anesthetics. METHODS: A standardized inoculum of bacteria commonly associated with surgical site infection was inoculated into a suspension of 1% lidocaine, 0.25% bupivacaine, Exparel (proprietary liposomally packaged 1.3% bupivacaine), and normal saline as a growth control. RESULTS: In all five bacteria tested, the medium inoculated with traditional local anesthetics reduced growth to a greater degree than LB-inoculated plates. Both conventional local anesthetics reduced the growth of all bacteria when compared with the control with the exception of methicillin-susceptible Staphylococcus aureus growth in bupivacaine. LB-inoculated plates had equivalent growth to the control in all plates with the exception of Escherichia coli plates which demonstrated superior growth. CONCLUSIONS: The results of this simple ex-vivo model suggest that the liposomal packaging of bupivacaine may decrease this local anesthetic's innate antibacterial properties.

Reducing colorectal surgical site infections: a novel, resident-driven, quality initiative.

BACKGROUND: Surgical site infections (SSIs) cause significant patient morbidity and increase costs. This work prospectively examines our institutional effort to reduce SSIs through a resident-driven quality initiative. METHODS: A general surgery resident-championed, evidenced-based care bundle for patients undergoing colorectal surgery at a single academic institution was developed using attending mentorship. National Surgical Quality Improvement Program definitions for SSIs were used. Data were collected prospectively and bundle compliance was monitored using a checklist. The primary outcome compared SSIs before and after implementation. RESULTS: In the 2 years preceding standardization, 489 colorectal surgery cases were performed. SSIs occurred in 68 patients (13.9% SSI rate). Following implementation of the bundle, 212 cases were performed with 10 SSIs (4.7% SSI rate, P < .01). Multivariate logistic regression analysis found a decrease in superficial and overall SSIs (odds ratio .17, 95% confidence interval .05 to .59; odds ratio .31, 95% confidence interval .14 to .68). CONCLUSIONS: These data demonstrate that resident-driven initiatives to improve quality of care can be a swift and effective way to enact change. We observed significantly decreased SSIs with a renewed focus on evidence-based, standardized patient care.

Colonic Schwannoma: A Case Study and Literature Review of a Rare Entity and Diagnostic Dilemma.

An asymptomatic 73-year-old woman was found to have a submucosal mass in the descending colon on routine colonoscopy. A CT scan revealed a 31 × 28 × 31 mm lesion in the same location. Previous biopsy proved to be nondiagnostic, and the patient underwent a laparoscopic descending colon resection. Histologic evaluation of the tumor revealed a low grade spindle cell neoplasm with strong, diffuse positivity for S-100 protein by immunohistochemistry, leading to the diagnosis of schwannoma. A review of the literature revealed intestinal schwannoma to be a rare disease entity, with only about 50 cases previously reported.

Anastomotic leaks after colorectal anastomosis occurring more than 30 days postoperatively: a single-institution evaluation.

National hospital registries only report colorectal anastomotic leaks (ALs) within 30 days postoperatively. The aim of our study was to determine the incidence and significance of ALs that occur beyond 30 days postoperatively. We performed a retrospective review of our prospective database from June 2008 to August 2012. A total of 504 patients were included. These patients were operated on by two surgeons. Any clinical or radiographic abnormalities were considered to be an anastomotic imperfection. A total of 504 patients were reviewed with a total of 18 (3.6%) anastomotic leaks. Six leaks (31.6% of leaks) were diagnosed more than 30 days postoperatively (P < 0.001). Of the 18 leaks, interventional radiology drainage was performed for four cases and 14 patients required reoperation. All six delayed leaks required reoperation. There was one leak that occurred under 30 days, which was discovered on autopsy. The median follow-up was 12 months (range, 1 to 4 months). All the delayed leak patients presented with fistulas, whereas 58 per cent of typical leak patients presented with the triad of leukocytosis, fever, and abdominal pain. Colorectal anastomotic leaks can occur after the 30-day postoperative period. In patients with vague and atypical abdominal findings, anastomotic leak must be suspected. More systematic, prospective studies are required to help us further understand the risk factors and natural history of anastomotic failures in elective colorectal surgery.

American Society of Anesthesiologists class and Charlson's comorbidity index as predictors of postoperative colorectal anastomotic leak: a single-institution experience.

BACKGROUND: The American Society of Anesthesiologists (ASA) physical status classification and Charlson comorbidity index (CCI) was adopted to assess patients' physical condition before surgery. Studies suggest that ASA score and CCI might be a prognostic criterion (indicator) for patient outcome. The aim of this study is to determine if ASA classification and CCI can determine the risk of anastomotic leaks (AL) in patients who underwent colorectal surgery. METHODS: A retrospective analysis of 505 consecutive colorectal resections with primary anastomoses between 2008 and 2012 was performed at a university hospital. ASA score, CCI, surgical procedure, length of stay, age, body mass index (BMI), comorbidities, and postoperative outcomes were analyzed. RESULTS: Two hundred sixty-five patients had an ASA score of I and II, 227 patients had an ASA score of III, and 13 patients had an ASA score of IV. A total of 19 patients had an anastomotic leak (ASA I-II: 5 patients, 1.9%; ASA III: 12 patients, 5.58%; ASA IV: 2 patients, 18.18%). A higher ASA score was significantly associated with AL on further analysis (OR: 2.99, 95% CI: 1.345-6.670, P = 0.007). When matched for age, BMI, and CCI on logistic regression analysis, increased ASA level was independently related to an increased likelihood of leak (OR(steroids) = 14.35, P < 0.01; OR(ASA_III v I-II) = 2.02, P = 0.18; OR(ASA_IVvI-II) = 8.45, P = 0.03). There were no statistically significant differences in means between the leak and no-leak patients with respect to age (60.69 versus 65.43, P = 0.17), BMI (28.03 versus 28.96, P = 0.46), and CCI (6.19 versus 7.58, P = 0.09). CONCLUSIONS: ASA score, but not CCI, is independently associated with anastomotic leak. Patients with a high ASA class should be closely followed postoperatively for AL after colorectal operations.

Rectal prolapse.

Rectal prolapse is a condition that usually requires surgical intervention to correct. Abdominal and perineal approaches are well described in the literature. Abdominal approaches have traditionally been reserved for young healthy patients, but this has been challenged by perineal approaches with excellent outcomes. Laparoscopic techniques have been shown to be effective and equivalent to traditional laparotomy techniques.

Survivin-induced Aurora-B kinase activation: A mechanism by which APC mutations contribute to increased mitoses during colon cancer development.

APC mutations initiate most colorectal cancers (CRCs), but cellular mechanisms linking this to CRC pathology are unclear. We reported that wild-type APC in the colon down-regulates the anti-apoptotic protein survivin, and APC mutation up-regulates it, explaining why most CRCs display survivin overexpression and apoptosis inhibition. However, it does not explain another hallmark of CRC pathology--increased mitotic figures and cell proliferation. Because survivin activates aurora-B kinase (ABK) in vitro, catalyzing mitosis, we hypothesized that in normal colonic crypts, APC controls ABK activity, while in neoplastic APC-mutant crypts, ABK activity is up-regulated, increasing mitosis. We quantitatively mapped intracryptal distributions of survivin, ABK, and markers of activated downstream signaling and mitosis (INCENP, phospho-histone-H3, phospho-centromere-protein-A). In normal crypts, gradients for these markers, ABK:survivin:INCENP complexes, and ABK activity were highest in the lower crypt (inverse to the APC gradient). In neoplastic crypts that harbor APC mutations, proliferating (Ki-67+) cells and cells expressing survivin, ABK, and phospho-histone-H3 were distributed farther up the crypt. Hence, as cells migrate up neoplastic crypts, transitions between cell phenotypes (eg, from stem to proliferating) appear delayed. In CRC cell lines, increasing wild-type APC, inhibiting TCF-4, or decreasing survivin expression down-regulated ABK activity. Thus, APC mutation-induced up-regulation of the survivin/ABK cascade can explain delayed crypt cell maturation, expansion of proliferative cell populations (including mitotic figures), and promotion of colon tumorigenesis.

Anastomotic leak rate after low anterior resection for rectal cancer after chemoradiation therapy.

Anastomotic leak may be the most concerning complication after colorectal anastomosis. To compare open with laparoscopic rectal resection, we must have accurate leak rates in patients who have received neoadjuvant chemoradiation therapy to serve as a benchmark for comparison. All patients who had preoperative chemoradiation therapy with rectal resection and low pelvic anastomosis for cancer in a single colorectal practice over a 7-year period were retrospectively reviewed. All patients had proximal diversion and a contrast enema study before stoma reversal. Eighty-seven consecutive patients were included in the study. Average age was 58 years. Fifty-nine per cent of patients were male. Sixty-six per cent were smokers. Pathologic T stage was 5 per cent T0, 16 per cent T1, 28 per cent T2, 47 per cent T3, and 5 per cent T4. Seventy-five per cent of patients were pathologically lymph node-negative. Average time to stoma reversal was 122 days. Total anastomotic leak rate was 10.3 per cent (8% clinical leaks). Five (56%) patients with leak successfully underwent reversal of their diverting stoma (average time to reversal, 290 days). Patients who had the complication of anastomotic leakage had less likelihood of stoma reversal and a significantly prolonged time to stoma reversal.

Outcomes of low anterior resection anastomotic leak after preoperative chemoradiation therapy for rectal cancer.

Anastomotic leak remains a major cause of morbidity and mortality after colorectal surgery, especially with low anastomoses. The aim of this study was to assess outcomes of patients who developed an anastomotic leak after low anterior resection of the rectum for rectal cancer. An Institutional Review Board-approved retrospective review of 89 consecutive patients undergoing open low anterior resection with primary anastomosis for cancer of the mid/lower rectum at a single institution between January 2001 and December 2008 was performed. All patients received neoadjuvant chemotherapy and radiation therapy. Proximal diversion was performed in all patients. Perioperative data were collected and analyzed with attention to management and outcomes after development of anastomotic leak. Nine patients (10.1%) developed anastomotic leak. Mean age was 62 years. Mean tumor level was 4.8 cm above the anal verge. Symptomatic anastomotic leak developed in seven (78%) patients. Percutaneous drainage was performed in five (55.6%) patients with an average of 4.4 procedures required for management of anastomotic leak. Five (55.6%) patients required reoperation. Only two procedures (25%) involved laparotomy. No operative procedures were performed emergently. There were no mortalities. Excluding one patient who received completion proctectomy for local recurrence, restoration of intestinal continuity was achieved in five (63%) of eight patients. Mean time to stoma closure was 289 days. The potentially lethal complication of anastomotic leak after low anterior resection for rectal cancer can be managed expectantly and electively in patients who are proximally diverted with the expectation of stoma reversal in the long term.

Stapled hemorrhoidopexy: outcome assessment.

Since its introduction as a new procedure for the surgical management of hemorrhoidal disease in 1993, stapled hemorrhoidopexy has become increasingly popular. This has been mostly the result of the reported reduction in postoperative pain. This study was designed to review retrospectively 152 patients combined from a 3-year period in a three-surgeon private colorectal practice and a 1-year period from an academic colon and rectal surgery training program. All patients had either grade II or III hemorrhoidal prolapse. There were 78 male (mean age, 52 years) and 74 female patients (mean age, 54 years). A total of 133 patients (87.5%) were treated on an ambulatory basis, with 131 patients (86%) given monitored sedation with local anesthesia. Postoperative complications were seen in 49 patients (32%); 33 were for bleeding, with four requiring operative control. Subsequent associated anorectal procedures were performed on 14 patients (9.2%). Of the original 152 patients, 78 participated in a postoperative survey. Of these patients, 67.9 per cent stated that their postoperative pain was less than expected. Seventy-one patients (91%) stated significant improvement or complete resolution of their symptoms, and 73.1 per cent returned to normal activity in less than 2 weeks. Eighty-nine per cent of patients surveyed stated they would recommend hemorrhoidopexy to others.

Colonic crypt changes during adenoma development in familial adenomatous polyposis: immunohistochemical evidence for expansion of the crypt base cell population.

Familial adenomatous polyposis patients, who have a germline APC mutation, develop adenomas in normal-appearing colonic mucosa, and in the process usually acquire a mutation in the other APC allele as well. Nonetheless, the cellular mechanisms that link these initiating genetic changes with the earliest tissue changes (upward shift in the labeling index) in colon tumorigenesis are unclear. Based on the tenet that colorectal cancer originates from crypt stem cells (SCs) and on our kinetic modeling, we hypothesized that overpopulation of mutant colonic SCs is the missing link. Directly testing this hypothesis requires measuring changes in the size of the SC population, but specific markers for human colonic SCs are lacking. Hence, we used immunohistochemical mapping to study crypt base cells, of which SCs are a subset. Using colectomy specimens from 16 familial adenomatous polyposis and 11 control cases, we determined the topographic profiles of various cell populations along the crypt axis and the proportions of each cell type. In the formation of adenomatous crypts, the distribution of cells expressing crypt base cell markers (MSH2, Bcl-2, survivin) expanded toward the crypt surface and showed the greatest proportional increase (fivefold to eightfold). Cells expressing a marker for the upper crypt (p27(kip1)) shifted to the crypt bottom and showed the smallest increase. This suggests that: 1) during adenoma development, APC mutations cause expansion of the crypt base cell population, including crypt SCs; 2) SC overpopulation can explain the shifts in pattern of proliferative crypt cell populations in early colon tumorigenesis, and 3) mutant crypt SCs clonally expand to form colonic adenomas and carcinomas.

Longer time interval between completion of neoadjuvant chemoradiation and surgical resection does not improve downstaging of rectal carcinoma.

PURPOSE: An interval of six to eight weeks between completion of preoperative chemoradiation therapy and surgical resection of advanced rectal cancer has been described. Our purpose was to determine whether a longer time interval between completion of therapy and resection increases tumor downstaging and affects perioperative morbidity. METHODS: Forty patients with advanced adenocarcinoma of the rectum underwent preoperative chemoradiation on a prospective trial with irinotecan (50 mg/m2), 5-fluorouracil (225 mg/m2), and concomitant external-beam radiation (45-54 Gy) followed by complete surgical resection of the tumor with total mesorectal excision. The time interval between completion of chemoradiation and surgical resection ranged from 28 to 97 days. The patients were divided into two groups with 33 eligible patients: Group A (4-week to 8-week time interval; 28-56 days) and Group B (10-week to 14-week interval; 67-97 days). Tumor downstaging was compared between these two groups. The number of patients downstaged by at least one T stage, those downstaged by at least one N stage, those with pathologic complete responses, and those with only residual microscopic tumor foci were compared. Postoperative length of stay, estimated blood loss, perioperative morbidity, and sphincter-sparing procedures were also compared. Chi-squared tests and Student's t-test were calculated. RESULTS: Group A had 19 patients, and Group B had 14 patients. Patient demographics were comparable. Mean age was 52 years, and 70 percent of patients were male. There were no deaths. There were no statistical differences in perioperative morbidity, with three anastomotic leaks in Group A. Tumors were downstaged in 58 percent of patients in Group A and 43 percent of those in Group B (P = 0.61). Nodal downstaging occurred in 78 percent of Group A and 67 percent of Group B (P = 0.9). The pathologic complete response rate was 21 percent in Group A and 14 percent in Group B (P = 0.97), and a residual microfocus of tumor was found in 33 percent of patients in Group A and 42 percent of those in Group B (P = 0.90). These differences were not statistically significant. CONCLUSIONS: Perioperative morbidity is not affected by longer intervals. A longer interval between completion of neoadjuvant chemoradiation and surgical resection may not increase the tumor response rate of advanced rectal cancer in this cohort.