Experiments and Molecular Simulations to Study the Effect of Surface-Active Compounds in Mixtures of Model Oils on CO2 Corrosion during Intermittent Oil-Water Wetting.

Intermittent oil-water wetting can have a significant effect on the internal corrosion of steel pipelines. This paper presents a combined experimental and molecular modeling study of several influential factors on the surface properties and corrosion behavior of mild steel in CO2 environments. The influence of different model oils (LVT-200 and Aromatic-200) and select surface-active compounds (myristic acid, cyclohexane butyric acid, and oleic acid) on the corrosion behavior of carbon steel during intermittent oil-water wetting was determined by measuring the corrosion rate after intermittent wetting cycles. The interfacial tension measurements were performed to study the incorporation of the oil phase along with surface-active molecules in the protective layer formed on the specimen surface. Results showed that the interfacial tension for an aromatic oil-water interface is lower than that for an aliphatic oil-water interface. To understand this result, molecular dynamics simulations of oil-water interfaces were performed in the presence of surface-active molecules and different oils to analyze the structure of the layer formed at the interface. The simulations supported the hypothesis that aromatic molecules are less structured at the interface, which results in the incorporation of more water molecules into the protective layer formed at the steel surface, causing a higher corrosion rate. On the other hand, the simulations revealed that myristic acid in an aliphatic oil forms a well-aligned structure at the interface, devoid of any water molecules. This is in agreement with the hypothesis that the linear molecular structure of myristic acid favors the alignment of molecules at an aliphatic oil-water interface, resulting in a lower interfacial tension and more effective corrosion mitigation as compared to the other two nonlinear compounds tested. It is concluded that an important factor controlling the corrosion behavior is the molecular structure of the oil-water interface, which is adopted by the steel surface layer through the Langmuir-Blodgett process.

Design and characterization of synthetic fungal-bacterial consortia for direct production of isobutanol from cellulosic biomass.

Synergistic microbial communities are ubiquitous in nature and exhibit appealing features, such as sophisticated metabolic capabilities and robustness. This has inspired fast-growing interest in engineering synthetic microbial consortia for biotechnology development. However, there are relatively few reports of their use in real-world applications, and achieving population stability and regulation has proven to be challenging. In this work, we bridge ecology theory with engineering principles to develop robust synthetic fungal-bacterial consortia for efficient biosynthesis of valuable products from lignocellulosic feedstocks. The required biological functions are divided between two specialists: the fungus Trichoderma reesei, which secretes cellulase enzymes to hydrolyze lignocellulosic biomass into soluble saccharides, and the bacterium Escherichia coli, which metabolizes soluble saccharides into desired products. We developed and experimentally validated a comprehensive mathematical model for T. reesei/E. coli consortia, providing insights on key determinants of the system's performance. To illustrate the bioprocessing potential of this consortium, we demonstrate direct conversion of microcrystalline cellulose and pretreated corn stover to isobutanol. Without costly nutrient supplementation, we achieved titers up to 1.88 g/L and yields up to 62% of theoretical maximum. In addition, we show that cooperator-cheater dynamics within T. reesei/E. coli consortia lead to stable population equilibria and provide a mechanism for tuning composition. Although we offer isobutanol production as a proof-of-concept application, our modular system could be readily adapted for production of many other valuable biochemicals.

Prospective multicenter study of a synthetic bioabsorbable anal fistula plug to treat cryptoglandular transsphincteric anal fistulas.

BACKGROUND: Although interest in sphincter-sparing treatments for anal fistulas is increasing, few large prospective studies of these approaches have been conducted. OBJECTIVE: The study assessed outcomes after implantation of a synthetic bioabsorbable anal fistula plug. DESIGN: A prospective, multicenter investigation was performed. SETTING: The study was conducted at 11 colon and rectal centers. PATIENTS: Ninety-three patients (71 men; mean age, 47 years) with complex cryptoglandular transsphincteric anal fistulas were enrolled. Exclusion criteria included Crohn's disease, an active infection, a multitract fistula, and an immunocompromised status. INTERVENTION: Draining setons were used at the surgeon's discretion. Patients had follow-up evaluations at 1, 3, 6, and 12 months postoperatively. MAIN OUTCOME MEASURES: The primary end point was healing of the fistula, defined as drainage cessation plus closure of the external opening, at 6 and 12 months. Secondary end points were fecal continence, duration of drainage from the fistula, pain, and adverse events during follow-up. RESULTS: Thirteen patients were lost to follow-up and 21 were withdrawn, primarily to undergo an alternative treatment. The fistula healing rates at 6 and 12 months were 41% (95% CI, 30%-52%; total n = 74) and 49% (95% CI, 38%-61%; total n = 73). Half the patients in whom a previous treatment failed had healing. By 6 months, the mean Wexner score had improved significantly (p = 0.0003). By 12 months, 93% of patients had no or minimal pain. Adverse events included 11 infections/abscesses, 2 new fistulas, and 8 total and 5 partial plug extrusions. The fistula healed in 3 patients with a partial extrusion. LIMITATIONS: The study was nonrandomized and had relatively high rates of loss to follow-up. CONCLUSION: Implantation of a synthetic bioabsorbable fistula plug is a reasonably efficacious treatment for complex transsphincteric anal fistulas, especially given the simplicity and low morbidity of the procedure.

Use of a national registry to define a composite quality metric for rectal cancer.

BACKGROUND: Quality assessment in oncologic surgery has traditionally involved reporting discrete metrics that may be difficult for patients and referring providers to interpret. We define a composite quality metric (CQM) for resection in rectal cancer. METHODS: We queried the National Cancer Database to identify patients undergoing low anterior resection for clinical stage II-III rectal adenocarcinoma between 2010 and 2017. CQM was defined as appropriate neoadjuvant therapy, margin-negative resection, appropriate lymph node assessment, postoperative length of stay (LOS) < 75th percentile, and no 30-day readmission or mortality. RESULTS: 19,721 patients met inclusion criteria; 8,083 (41%) had a CQM. The most common reasons for failure to achieve CQM: inadequate node assessment (27%), prolonged LOS (26%). On Cox modeling, CQM (aHR 0.70, 95% CI [0.66, 0.75]) was associated with improved overall survival. CONCLUSION: CQM is independently associated with improved survival in rectal cancer and may be an effective measure of quality.

Is local excision an appropriate treatment modality in patients presenting with early-stage (cT1 N0 M0) rectal adenocarcinoma?

BACKGROUND: Prior studies evaluating the safety and efficacy of local excision relative to surgical resection in early-stage rectal adenocarcinoma have primarily included low rectal cancers treated with abdominoperineal resection as control comparison cohorts. The role of local excision in early-stage rectal adenocarcinoma is incompletely defined. METHODS: We queried the National Cancer Database to identify patients with cT1 N0 M0 rectal adenocarcinoma between 2004 and 2019. Patients undergoing abdominoperineal resection were excluded. Multivariable regression was used to identify factors associated with use of local excision instead of low anterior resection. Patients undergoing local excision were propensity score matched for age, sex, demographic characteristics, Charlson-Deyo comorbidity class score, and tumor grade and size to those undergoing low anterior resection. Short-term clinical outcomes and 5-year overall survival for matched cohorts were compared by standard methods. RESULTS: A total of 5,693 patients met inclusion criteria; 1,973 patients underwent local excision and 3,720 low anterior resection. Age (adjusted odds ratio 1.26; 95% confidence interval, 1.17-1.37), tumor histology (poorly differentiated histology: adjusted odds ratio 0.66; 95% confidence interval, 0.51-0.86), and size (>4 cm: adjusted odds ratio 0.20; 95% confidence interval, 0.16-0.25) were associated with choice of intervention. On comparison of matched cohorts, patients undergoing LE demonstrated shorter hospital stay (2.4 ±9.8 vs 5.6 ±8.1 days; P < .001) and lower readmission rate (4% vs 7%; P = .002) but higher margin-positive resection rates (8% vs 2%; P < .001). Overall survival profiles for patients undergoing local excision were comparable with those for low anterior resection. CONCLUSION: In patients with cT1 N0 M0 rectal adenocarcinoma, local excision is associated with a higher margin-positive resection rate than low anterior resection but affords accelerated postprocedure recovery and comparable rates of overall survival.

ACCESS TO HEALTHCARE INSURANCE INCREASES THE RATES OF SURGERY FOR DIVERTICULITIS.

OBJECTIVE: The goal of this study was to examine the effect of the Affordable Care Act Medicaid expansion on rates of hospitalization and surgery for diverticulitis. STUDY SETTINGS: Data were obtained from the Healthcare Cost and Utilization Project State Inpatient Databases from 2010 to 2014. STUDY DESIGN: Retrospective cohort study analyzing adult patients undergoing surgery for diverticulitis in the expansion and nonexpansion states, pre (2010-2013) and post (2014) Medicaid expansion. FINDINGS: There were a total of 159,419 patients in our cohort analysis. 75,575 (49%) in expansion states and 81,844 (51%) in non-expansion states. In multivariable Poisson regression, the rate of surgical procedures for diverticular disease increased among Medicaid patients (IRR 1.80; p<.01) whereas surgery rates in self-pay patients decreased (IRR 0.67; p<.01) in expansion states compared to non-expansion states. CONCLUSIONS: In states that expanded Medicaid coverage under the Affordable Care Act, the rate of surgery for diverticular disease in Medicaid patients increased. Therefore, legislation that increases healthcare access may increase the utilization of surgical care for diverticular disease.

Enhanced recovery after surgery: A clinical review of implementation across multiple surgical subspecialties.

Enhanced recovery after surgery (ERAS) is a multimodal protocol applied towards perioperative patient care. ERAS programs are implemented by a multidisciplinary team centered around the patient, incorporating outpatient clinical staff, preoperative nurses, anesthesiologists, operative nurses, postoperative recovery staff, floor inpatient nurses, dieticians, physical therapists, social workers, and surgeons. Initial studies on perioperative care measures focused on cardiac surgery. Subsequently, the development of the ERAS Study Group in 2001 focused on colorectal surgery and postoperative outcome measures. Today, ERAS protocols have been implemented across many surgical subspecialties including: bariatric, breast, plastic, cardiac, colorectal, esophageal, head and neck, hepatic, gynecologic, neurosurgical, orthopedic, pancreatic, thoracic, and urologic surgery. The goal of ERAS programs is to promote rapid recovery as quantified by decreasing the length of hospital stay, complications, and cost of specific surgical interventions. In the setting of the opioid crisis in America, there is also an increasing focus on minimizing perioperative narcotic use. The purpose of this review is to compare ERAS protocols across surgical subspecialties, focusing on quantified metrics of improvement, and to provide a clear and concise summary of the literature in regards to current ERAS practices and success rates.

Association of obesity with postoperative outcomes after proctectomy.

BACKGROUND: Prior efforts evaluating obesity as a risk factor for postoperative complications following proctectomy have been limited by sample size and uniform outcome classification. METHODS: The ACS NSQIP was queried for patients with non-metastatic rectal adenocarcinoma who underwent elective proctectomy. After stratification by BMI classification, multivariable modeling was used to identify the effect of BMI class on adjusted risk of 30-day outcomes controlling for patient, procedure, and tumor factors. RESULTS: Of 2241 patients identified, 33.4% had a normal BMI, 33.5% were overweight, 21.1% were obese, and 12.0% were morbidly obese. Increased risk of superficial surgical site infection (SSI) was observed in obese (OR 2.42, 95%CI:[1.36-4.29]) and morbidly obese (OR 3.29, 95%CI:[1.77-6.11]) patients when compared to normal BMI. Morbid obesity was associated with increased risk of any complication (OR 1.44, 95%CI:[1.05-1.96]). BMI class was not associated with risk adjusted odds of anastomotic leak. CONCLUSIONS: Morbid obesity is independently associated with an increased composite odds risk of short-term morbidity following elective proctectomy for cancer primarily due to increased risk of superficial SSI.

Do prolonged operative times obviate the benefits associated with minimally invasive colectomy?

BACKGROUND: Minimally invasive colectomy is associated with improved length of stay and decreased postoperative morbidity. Little is known regarding the impact of prolonged operative time on the benefits afforded by minimally invasive colectomy. METHODS: The American College of Surgeons National Surgical Quality Improvement Program procedure targeted colectomy dataset was queried to identify elective right and left colectomies performed between 2011 and 2017. Multivariable modeling was used to compare rates of composite 30-day death or serious morbidity, overall morbidity, mortality, anastomotic leak, surgical site infection, and length of stay for prolonged minimally invasive cases to those for average duration open cases. RESULTS: A total of 16,602 right colectomies and 36,557 left colectomies were identified. Median operative times for open and minimally invasive right colectomies were 107 min and 129 min (P < .01), while that for open left colectomies was 128 min and 156 min for minimally invasive left colectomies (P < .01). Cohorts were stratified by quartiles of operative time with the highest (fourth) quartile defined as a prolonged operating time. When compared with an average duration open colectomy, prolonged minimally invasive right colectomies and left colectomies were associated with decreased risk-adjusted rates of overall morbidity, surgical site infection, and with lesser lengths of stay (P < .05). Prolonged minimally invasive left colectomies were also associated with improved rates of composite 30-day death or serious morbidity relative to average open left colectomies (odds ratio 0.66, 95% confidence interval, 0.54-0.79). CONCLUSION: Prolonged operating times of an minimally invasive approach do not obviate the benefits of an minimally invasive approach to colectomy.

Longer Operative Time and Intraoperative Blood Transfusion Are Associated with Postoperative Anastomotic Leak after Lower Gastrointestinal Surgery.

Anastomotic leak after lower gastrointestinal surgery is a complication with potential for high morbidity, mortality, and increased costs. A single-institution retrospective chart review was performed on all patients who underwent lower gastrointestinal surgery between June 2009 and June 2013. Fifty-seven variables were included in our analysis and their association with postoperative anastomotic leak was examined. Nine hundred fifty-two patients underwent 983 lower gastrointestinal anastomoses with an overall leak rate in this series of 6 per cent. Type of intestinal anastomosis created (P < 0.00005), operative indication (P < 0.015), operation performed (P < 0.014), intraoperative blood transfusion (P < 0.017), and intraoperative surgical drain placement (P < 0.022) were all predictive of anastomotic leak. Anastomotic leak rate increased by 1.3 times for every additional hour in the operating room after three hours. Both increasing operation time and intraoperative blood transfusions were associated with an increased rate of anastomotic leak. When operative time extends beyond three hours or in those cases were blood transfusions are given, surgeons should consider taking steps to minimize the risks of a potential anastomotic leak.

New techniques in the treatment of common perianal diseases: stapled hemorrhoidopexy, botulinum toxin, and fibrin sealant.

There have been several recent advances in the treatment of common perianal diseases. Stapled hemorrhoidopexy is a procedure of hemorrhoidal fixation, combining the benefits of rubber band ligation into an operative technique. The treatment of anal fissure has typically relied upon internal sphincterotomy; however, it carries a risk of incontinence. The injection of botulinum toxin represents a new form of sphincter relaxation, without division of any sphincter muscle; morbidity is minimal and results are promising. For the treatment of fistula in a fistulotomy remains the gold standard, however, it carries significant risk of incontinence. Use of fibrin sealant to treat fistulae has been met with variable success. It offers sealing of the tract, and then provides scaffolding for native tissue ingrowth.

Retrorectal cyst: a rare tumor frequently misdiagnosed.

BACKGROUND: The rarity of retrorectal cysts and their nonspecific clinical presentations often lead to misdiagnoses and inappropriate operations. In recent years, several such patients have been referred to our institutions for evaluation and treatment of misdiagnosed retrorectal cysts. A review of these patients is presented. STUDY DESIGN: Medical records of the colorectal surgery divisions at two institutions were reviewed. Patients found to have previously misdiagnosed retrorectal cysts were identified. Preliminary diagnoses, radiologic examinations, operative procedures, and final diagnoses were obtained. RESULTS: Seven patients with retrorectal cysts who had been misdiagnosed before referral were identified. These patients had been treated for fistulae in ano, pilonidal cysts, perianal abscesses; psychogenic, lower back, posttraumatic, or postpartum pain, and proctalgia fugax before the correct diagnosis was made. Patients underwent an average of 4.1 operative procedures. Physical examination in combination with CT scanning made the correct diagnosis in all patients. All patients underwent successful resection through a parasacrococcygeal approach, and six of seven did not require coccygectomy. The resected tumors included four hamartomas, two epidermoid cysts, and one enteric duplication cyst. CONCLUSIONS: Retrorectal cysts are a rare entity that can be difficult to diagnose without a high index of clinical suspicion. A history of multiple unsuccessful procedures should alert the clinician to the diagnosis of retrorectal cyst. Once suspected, the correct diagnosis can be made with physical examination and a CT scan before a definitive surgical procedure.

Hand-sewn versus stapled intestinal anastomoses in a chronically steroid-treated porcine model.

Chronic steroid treatment is known to delay wound healing; however, there are no trials examining stapled intestinal anastomoses in subjects chronically treated with steroids. The current study compares mechanically stapled to manually sutured intestinal anastomoses in a steroid-treated porcine model. Twenty adult male pigs were treated with daily prednisolone (0.5 mg/kg IM) for 14 days. The pigs were divided between hand-sewn and stapled groups. All pigs underwent a laparotomy with construction of a jejunojejunostomy, an ileocecostomy, and a colocolostomy. Pigs were sacrificed on postoperative day 4. Bursting pressure, collagen content, and inflammatory scores were used to evaluate each anastomosis. Bursting pressure was greater for the hand-sewn group at the jejunojejunostomies only (1.52 vs 0.79 psi; P < 0.001). The collagen content and microscopic inflammatory scores were not significantly different at any location. The mean gross inflammatory score was greater for the hand-sewn colocolostomies only (5.20 vs 4.00; P < 0.01). Stapled ileocecostomies and colocolostomies appear to heal as well as hand-sewn anastomoses. This may not be true of the jejunojejunostomies as evidenced by the decreased bursting pressures. These data may provide evidence in support of the use of stapled anastomoses in steroid-treated patients.

Anal melanoma.

Anal melanoma is rare and aggressive malignancy. Patients commonly present with advanced, even metastatic disease. Unlike cutaneous melanoma, anal melanoma has no known risk factors. Surgical excision remains the cornerstone of therapy. There are no long-term survivors of stage II or III disease; therefore, early diagnosis and treatment remain crucial. There are no trials definitively proving abdominal perineal resection (APR) or wide local excision (WLE) to yield superior long-term survival. APR may offer a higher rate of local control, whereas WLE offers a much less morbid operation. Adjuvant chemotherapy, interferon, and radiation may offer some benefit.

Treatment of fistulas-in-ano with fibrin sealant in combination with intra-adhesive antibiotics and/or surgical closure of the internal fistula opening.

PURPOSE: The treatment of fistulas-in-ano with fibrin sealant injection has been moderately successful. Failures can be caused by persistent infection within the tract or early expulsion of the clot. In an attempt to improve the success rate, we examined three modifications of the sealant procedure: the addition of cefoxitin to the sealant, surgical closure of the primary opening, or both. METHODS: A prospective, randomized, clinical trial was performed in which patients were treated with Tisseel-VH fibrin sealant according to previously published procedures. In addition, patients were randomized to receive intra-adhesive cefoxitin, surgical closure of the primary opening, or both modifications. Cefoxitin, 100 mg, was added to the sealant for patients randomized to receive intra-adhesive antibiotics. For the appropriate patients, the primary fistula opening was closed with a 3-0 absorbable suture. If fistulas failed to heal, patients were offered a single retreatment with sealant. RESULTS: Twenty-four patients were treated in the cefoxitin arm, 25 in the closure arm, and 26 in the combined arm. Median duration of fistulas was 12 months. Patients were followed for a mean of 27 months postoperatively. There was no postoperative incontinence or complications related to the sealant itself. Initial healing rates were 21 percent in the cefoxitin arm, 40 percent in the closure arm, and 31 percent in the combined arm (P = 0.35). One of five patients in the cefoxitin arm, one of seven patients in the closure arm, and one of six patients in the combined arm were successfully retreated; final healing rates were 25, 44, and 35 percent respectively (P = 0.38). CONCLUSIONS: Treatment of fistula-in-ano with fibrin sealant with closure of the internal opening was somewhat more successful than sealant with cefoxitin or the combination, however this did not achieve statistical significance. None of the three modifications were more successful than historic controls at our institution treated with sealant alone. Therefore, the addition of intra-adhesive cefoxitin, closure of the internal opening, or both are not recommended modifications of the fibrin sealant procedure.

Stapled hemorrhoidopexy: the argument for usage.

Stapled hemorrhoidopexy is a new procedure for the treatment of symptomatic internal hemorrhoids. Experience and prospective trials are helping to define this procedure's role. Published data confirm that stapled hemorrhoidopexy offers similar control of symptoms with the benefits of reduced postoperative pain when compared with excisional techniques. Reduction in pain is the most significant benefit of this operation. Clearly, the cost of the stapling device exceeds the cost of the sutures required to perform an excisional hemorrhoidectomy. Patients should undergo medical therapy and rubber band ligation first; however, patients being considered for excisional hemorrhoidectomy should be offered stapled hemorrhoidectomy as a less painful alternative.

Primary repair of penetrating colon injuries: a systematic review.

PURPOSE: Primary repair of penetrating colon injuries is an appealing management option; however, uncertainty about its safety persists. This study was conducted to compare the morbidity and mortality of primary repair with fecal diversion in the management of penetrating colon injuries by use of a meta-analysis of randomized, prospective trials. METHODS: We searched for prospective, randomized trials in MEDLINE (1966 to November 2001), the Cochrane Library, and EMBase using the terms colon, penetrating, injury, colostomy, prospective, and randomized. Studies were included if they were randomized, controlled trials that compared the outcomes of primary repair with fecal diversion in the management of penetrating colon injuries. Five studies were included. Reviewers performed data extraction independently. Outcomes evaluated from each trial included mortality, total complications, infectious complications, intra-abdominal infections, wound complications, penetrating abdominal trauma index, and length of stay. Peto odds ratios for combined effect were calculated with a 95 percent confidence interval for each outcome. Heterogeneity was also assessed for each outcome. RESULTS: The penetrating abdominal trauma index of included subjects did not differ significantly between studies. Mortality was not significantly different between groups (odds ratio, 1.70; 95 percent confidence interval, 0.51-5.66). However, total complications (odds ratio, 0.28; 95 percent confidence interval, 0.18-0.42), total infectious complications (odds ratio, 0.41; 95 percent confidence interval, 0.27-0.63), abdominal infections including dehiscence (odds ratio, 0.59; 95 percent confidence interval, 0.38-0.94), abdominal infections excluding dehiscence (odds ratio, 0.52; 95 percent confidence interval, 0.31-0.86), wound complications including dehiscence (odds ratio, 0.55; 95 percent confidence interval, 0.34-0.89), and wound complications excluding dehiscence (odds ratio, 0.43; 95 percent confidence interval, 0.25-0.76) all significantly favored primary repair. CONCLUSION: Meta-analysis of currently published randomized, controlled trials favors primary repair over fecal diversion for penetrating colon injuries.

Superselective mesenteric embolization with microcoils in a porcine model.

PURPOSE: There is a lack of data regarding the degree of ischemic change that may occur in small and large bowel after superselective arterial embolotherapy with platinum microcoils. The purpose of this study was to gain a clearer understanding of the ischemic complications of superselective embolization of peripheral mesenteric arteries with microcoils by gross and histologic examination of postembolectomy bowel specimens at several time intervals in an adult porcine model. METHODS: Two-millimeter platinum microcoils with fibrils were superselectively deployed into six isolated mesenteric branch vessels in each of nine adult pigs. The animals were observed for two days (n = 3), one month (n = 3), or three months (n = 3) and then killed. At necropsy, intestines were examined for gross abnormalities. Sections of bowel containing microcoils were identified under fluoroscopy, resected, and evaluated histologically. RESULTS: A total of 54 microcoils were deployed into the distal arterial mesentery supplying the jejunum (n = 14), ileum (n = 26), and colon (n = 14) of nine adult pigs. Each animal received six microcoils. There were no clinical complications, and all pigs gained weight during their observation periods. Gross examination of the intestines did not reveal any evidence of acute or chronic ischemia. The coils were found in the distal arterial vasculature of the intestine. Histologic examination revealed mild superficial necrosis of villous tips in several samples; however, this finding is likely related to a fixation artifact rather than ischemic injury. There was no other histologic evidence suggestive of ischemic injury. CONCLUSIONS: Gross and histologic findings after superselective arterial embolotherapy demonstrated minimal changes in the bowel, and there were no significant clinical consequences to the animals. We conclude that transcatheter arterial embolotherapy in pigs is safe and may be applicable in the control of massive lower gastrointestinal hemorrhage in humans.

Early experience with stapled hemorrhoidectomy in the United States.

INTRODUCTION: We report the early results of patients treated with stapled hemorrhoidectomy, which has recently been introduced into the United States. METHODS: Sixty-eight patients with symptomatic hemorrhoids were treated at two institutions with the Proximate HCS Hemorrhoidal Circular Stapler supplied by Ethicon Endo-Surgery. Patients were prospectively evaluated for functional recovery and postoperative pain on a 1 to 10 scale. RESULTS: There were 45 (66 percent) males and 23 (34 percent) females with a mean age of 56 years and median duration of symptoms of 5 years. The mean operative time was 22.2 minutes. The operation was performed with spinal (50 percent), local (40 percent), or general (10 percent) anesthesia and as an outpatient (56 percent) or overnight admission (44 percent). Ninety-three percent of patients remained asymptomatic with a mean follow-up of 34 weeks, whereas the remaining 7 percent required either surgical excision or rubber band ligation for persistent symptoms. There was no mortality, new incontinence, fecal impaction, or persistent pain. The total morbidity was 19 percent, with urinary retention as the most common complication (12 percent). The mean pain score decreased from 3.6 on postoperative Day 1 to 1.4 at postoperative Day 7. Ninety-nine percent of patients made a complete functional recovery by postoperative Day 7. CONCLUSIONS: Stapled hemorrhoidectomy is safe, effective, and can be performed as an outpatient procedure with local or regional anesthesia. There seems to be minimal postoperative pain and early recovery, although a benefit over traditional hemorrhoidectomy needs to be proven in a randomized trial.