Papers by Christopher Mantyh
Journal of Gastrointestinal Surgery, Sep 13, 2012
Introduction The optimal timing of primary and metastatic tumor management in patients with synch... more Introduction The optimal timing of primary and metastatic tumor management in patients with synchronous hepatic colorectal metastases remains controversial. We aimed to compare perioperative outcomes of simultaneous colorectal/liver resection (SCLR) with isolated resections utilizing a national clinical database. Methods NSQIP data from 2005 to 2009 were examined to construct risk-adjusted generalized linear models and to calculate group-specific predicted estimates. These were used to compare 30-day perioperative outcomes among patients undergoing SCLR with colorectal (CR) and liver resections (LR) only in patients with metastatic colorectal cancer. Results A total of 3,983 patients were identified, who underwent SCLR (192), LR (1,857), or CR (1,934). Rectal resection was performed in 45 (23.4 %) SCLR patients and 269 (13.9 %) CR patients (p<0.001). Major hepatectomy was performed in 69 (35.9 %) SCLR patients and 774 (41.7 %) LR patients (p00.12).
Journal of Gastrointestinal Surgery, Nov 8, 2013
Although pelvic exenteration (PE) remains an important treatment for advanced pelvic malignancies... more Although pelvic exenteration (PE) remains an important treatment for advanced pelvic malignancies, it has historically been associated with high morbidity and mortality with unclear long-term benefits. The objectives of this study were (1) estimate complication and mortality rates, (2) determine predictors of complications, and (3) estimate overall survival after PE for patients with locally advanced colorectal and bladder tumors. A total of 377 patients were retrospectively identified from the 2005-2010 NSQIP PUF and an additional 1,111 from the 2004-2010 Surveillance Epidemiology and End Results database with T4M0 colorectal or bladder cancers. A logistic regression model was fitted to estimate early morbidity and mortality. The Kaplan-Meier method was used to estimate survival after PE compared to nonoperative management. Fifty-seven percent of patients had a complication, but 30-day mortality was only 2%. Patients with preoperative dyspnea and higher ASA class had the highest risk of morbidity. PE for the treatment of T4M0 rectal and bladder cancer was associated with significantly improved long-term survival compared to nonoperative therapy. PE is associated with a high complication rate but low 30-day mortality. The results of this study provide strong evidence to support PE as a viable treatment option for locally advanced rectal and bladder malignancies in appropriately selected patients.
Brain Research, May 1, 1996
Recent pharmacological and biochemical studies have suggested that there may be more than one mol... more Recent pharmacological and biochemical studies have suggested that there may be more than one molecular form of the neurokinin-1 receptor (NK-1), a long and short isoform differing in the length of their cytoplasmic carboxyl-terminal tails, but no definitive evidence of the existence of such NK-1 receptor isoforms in tissue has been presented. To examine whether these different isoforms are expressed in vivo we have compared the distribution of high affinity substance P (SP) binding sites (visualized by autoradiography with [125I]SP), with the distribution of the C-terminal epitope of the full length receptor (visualized with a specific antibody against the extreme C-terminal sequence). The former method labels both long and short forms of the NK-1 receptor, while the latter labels only the long form of the protein. In the rat there is a close correspondence of [125I]SP binding and NK-1 immunoreactivity in the striatum, suggesting that the long isoform predominates in this tissue. In the parotid and submaxillary gland, there are very high levels of [125I]SP binding but only low levels of NK-1 immunoreactivity, suggesting that expression of the short form predominates in these tissues. These results imply that different tissues express different ratios of the two isoforms of the NK-1 receptor. This differential expression provides the theoretical basis for tissue specific pharmacological targeting of NK-I receptors.
Gastroenterology, Dec 1, 1987
The Journal of Neuroscience, 1989
Journal of Surgical Research, Feb 1, 2014
Current Opinion in Urology, Jul 1, 2014
Iatrogenic rectourethral fistulas (RUFs) are a rare but challenging complication that can follow ... more Iatrogenic rectourethral fistulas (RUFs) are a rare but challenging complication that can follow the treatment of prostate cancer. We review the literature regarding the surgical management of RUFs and subsequent outcomes, focusing on a cause-specific approach. Iatrogenic RUFs are reported to occur in approximately 1% of patients treated with external-beam radiation therapy, in 1-6% of patients after radical prostatectomy, and in 5-9% following brachytherapy or cryotherapy after prostate cancer. Most of these patients will require surgical treatment at some point. Though there have been multiple surgical procedures described with varying degrees of success, there is no consensus as to the procedure of choice, though authors now agree on the importance of the interposition of healthy tissue in radiation-induced fistulas. The current literature regarding surgical approaches to the iatrogenic RUF in the prostate cancer patient highlights the importance of a cause-specific and often multidisciplinary approach, as well as the one that is most familiar to the individual surgeon, because there is often little difference in the approaches in terms of recurrence. However, given the high success rate and low complication rate, muscle transposition flap repairs remain an attractive surgical option for fistulas with unfavorable local conditions such as those present after radiation.
Journal of Surgical Research, Jul 1, 2014
Background: Few studies have examined the current status of ureteral stent use or the indications... more Background: Few studies have examined the current status of ureteral stent use or the indications for stenting, particularly in laparoscopic colorectal surgery. This study examines current national trends and predictors of ureteral stenting in patients undergoing major colorectal operations and the subsequent effects on perioperative outcomes. Methods: The 2005e2011 National Surgical Quality Improvement participant user files were used to identify patients undergoing laparoscopic segmental colectomy, low anterior resection, or proctectomy. Trends in stent use were assessed across procedure types. To estimate the predictors of stent utilization, a forward-stepwise logistic regression model was used. A 3:1 nearest neighbor propensity match with subsequent multivariable adjustment was then used to estimate the impact of stents. Results: A total of 42,311 cases were identified, of which 1795 (4.2%) underwent ureteral stent placement. Predictors of stent utilization included diverticular disease, need for radical resection (versus segmental colectomy), recent radiotherapy, and more recent calendar year. After adjustment, ureteral stenting appeared to be associated with a small increase in median operative time (44 min) and a trivial increase in length of stay (5.4%, P < 0.001). However, there were no significant differences in morbidity or mortality. Conclusions: We describe the clinical predictors of ureteral stent usage in this patient population and report that while stenting adds to operative time, it is not associated with significantly increased morbidity or mortality after adjusting for diagnosis and comorbidities. Focused institutional studies are necessary in the future to address the utility of ureteral stents in the identification and possible prevention of iatrogenic injury.
European Urology Supplements, Mar 1, 2019
Introduction & Objectives: Iatrogenic recto-urethral fistulas are a rare but life altering. Conse... more Introduction & Objectives: Iatrogenic recto-urethral fistulas are a rare but life altering. Conservative management often fails, leaving surgical repair as the treatment of choice, however the best choice for repair is debated with variable success rates reported in the literature. We looked at the success of the York-Mason utilized in a carefully selected patient population. Materials & Methods: We performed a review of recto-urethral fistula repair outcomes after prostate and rectal cancer treatment as well as posttraumatic injuries at our facility from 2002-2017 utilizing a York-Mason repair. Per an algorithm we formally implemented in 2012, patients without a prior history of radiation and a fistula smaller than 3 cm were considered ideal candidates and offered this type of repair. All patients underwent urinary diversion with an SPT and bowel diversion with either a colostomy or ileostomy prior to or at the time of their repair. We assessed the rates of objective healing-with RUG and proctoscopy-as well as ostomy reversal rates. Results: Over a 16-year period, of 65 patients undergoing surgery for recto-urethral fistula, 16 patients were repaired using a York-Mason procedure. Of these patients, all but one had objective confirmation of fistula healing and underwent reversal of their urinary and bowel diversion. The one failure in this series had a brachytherapy related fistula and underwent repair in 2006 prior to our firmly established criteria for using this procedure. Of the 10 patients for whom exact date of reversal is available, the average time to reversal was 5.3 months (median 4.5 months). There were no cases of fecal or gas incontinence. Conclusions: The York-Mason technique can be an effective procedure for recto-urethral fistula repair in a select population. We feel that the best candidates for this procedure have a small fistula <3 cm and do not have a history of radiation therapy. We also feel that the sphincter-sparing modification that was adopted in 2014 has augmented preservation of sphincter function. Since we have employed strict criteria to select the appropriate candidates for this surgery, we have had 100% success with not only fistula healing, but also restoration of urinary and bowel continuity.
Annals of Plastic Surgery, Feb 1, 2019
Background: Primary perineal closure following abdominal perineal resection (APR) is reported to ... more Background: Primary perineal closure following abdominal perineal resection (APR) is reported to have a wound complication rate as high as 66%, whereas flap reconstruction reduces wound complications to 15% to 35%. A modified de-epithelialized V-Y fasciocutaneous flap aims to further improve results in this patient population. Methods: To study the breaking force of a simple interrupted suture in either skin or subcutaneous fat, various quantitative assessments were performed in a porcine flap model using uniaxial static tensile testing with an Instron tensiometer, with a single or triple row of 3 Vicryl sutures in both skin and fat. An outcomes analysis was performed in 24 patients who underwent modified V-Y flap reconstruction after APR. Primary outcome was wound complications including infection, dehiscence, seroma, hematoma, and pelvic fluid collections. Results: Tensile strength of sutures anchored in skin was found to be up to 8 times stronger than sutures anchored in subcutaneous fat in a single row and 3 times as strong in 3 rows (breaking force, 500.2 N vs 263.7 N). In our patient cohort of 24 irradiated cancer patients, 10 (42%) had wound healing complications. Wound dehiscence of various degrees accounted for 80% of these complications. Five patients with wound complications (50%) had associated pelvic fluid collections (infection, 1; wound dehiscence, 4). Minor dehiscence was more likely to occur after suture removal and less likely to be associated with pelvic collections compared to patients with major dehiscence. Our study yields total complication rates lower than what is reported in the literature for anterolateral thigh or gracilis flap including much lower infection rates, and almost similar results to the commonly used vertical rectus myocutaneous muscle. Conclusion: Tension-free de-epithelialized V-Y flap use after APR effectively reconstructs the defect while eliminating an additional donor site. Benchtop studies suggest enhanced flap integrity yielded by layered closure. Wound complications can be managed with local care in their majority (90%). Staggering or delaying suture removal can decrease minor dehiscence. Based on analysis of our results, review of the literature and consideration of donor site morbidity, we believe that modified V-Y flap is the best approach for APR reconstruction in irradiated patients.
Journal of The American College of Surgeons, Apr 1, 2019
BACKGROUND In 2017, our hospital was identified as a high outlier for postoperative Clostridium d... more BACKGROUND In 2017, our hospital was identified as a high outlier for postoperative Clostridium difficile infections (CDIs) in the American College of Surgeons NSQIP semi-annual report. The Department of Surgery initiated a CDI task force with representation from Surgery, Infectious Disease, Pharmacy, and Performance Services to analyze available data, identify opportunities for improvement, and implement strategies to reduce CDIs. STUDY DESIGN Strategies to reduce CDIs were reviewed from the literature and the following multidisciplinary strategies were initiated: antimicrobial stewardship optimization of perioperative order sets to avoid cefoxitin and fluoroquinolone use was completed; penicillin allergy assessment and skin testing were implemented concomitantly; increased use of ultraviolet disinfectant strategies for terminal cleaning of CDI patient rooms; increased hand hygiene and personal protection equipment signage, as well as monitoring in high-risk CDI areas; improved diagnostic stewardship by an electronic best practice advisory to reduce inappropriate CDI testing; education through surgical grand rounds; and routine data feedback via NSQIP and National Healthcare Safety Network CDI reports. RESULTS The observed rate of CDIs decreased from 1.27% in 2016 to 0.91% in 2017. Cefoxitin and fluoroquinolone use decreased. Clostridium difficile infection testing for patients on laxatives decreased. Terminal cleaning with ultraviolet light increased. Handwashing compliance increased. Data feedback to stakeholders was established. CONCLUSIONS Our multidisciplinary CDI reduction program has demonstrated significant reductions in CDIs. It is effective, straightforward to implement and monitor, and can be generalized to high-outlier institutions.
Clinics in Colon and Rectal Surgery, Aug 1, 2007
There are 40,000 new rectal cancer cases diagnosed each year in the United States, representing t... more There are 40,000 new rectal cancer cases diagnosed each year in the United States, representing the second most common gastrointestinal malignancy (behind colon cancer). With the advent of sphincter preserving techniques, patients with mid and low colorectal cancers enjoy the benefits of better postoperative functional outcomes and quality of life; however, controversy exists over which reconstructive technique is superior in restoring bowel continuity. Construction of a straight coloanal anastomosis is technically simpler, but functional outcomes are inferior compared with colonic reservoirs. The purpose of this review is to summarize the current data regarding reconstructive techniques following proctectomy.
Gut, 2006
Background and aims: Activation of the vanilloid receptor subtype 1 (VR-1) results in release of ... more Background and aims: Activation of the vanilloid receptor subtype 1 (VR-1) results in release of proinflammatory peptides which initiate an inflammatory cascade known as neurogenic inflammation. We investigated its role in an acute model of surgically induced oesophagitis. Methods: Oesophagitis was induced by pyloric ligation in wild-type and VR-1 deficient mice. A subset of animals were administered the VR-1 antagonist capsazepine, famotidine, or omeprazole one hour before surgery. Five hours after surgery, myeloperoxidase activity (MPO), histological damage scores, intragastric pH, and immunocytochemical analysis of substance P (SP) receptor endocytosis were determined. Results: Oesophagitis induced knockout mice exhibited significantly lower levels of MPO activity, histological damage scores, and SP receptor endocytosis than wild-type mice. Inflammatory parameters were significantly reduced by acid inhibition and capsazepine in wild-type mice. Conclusions: We conclude that acute acid induced oesophagitis is reduced in animals lacking VR-1. This suggests that acid induced oesophagitis may act through VR-1 and that inhibition of the receptor may reduce inflammation.
The Journal of Urology, Apr 1, 2019
proximal and distal segments was maintained in the dorsal plane. The tip of the distal spatulated... more proximal and distal segments was maintained in the dorsal plane. The tip of the distal spatulated urethral margin was advance into the spatulation of the proximal margin, while the proximal tip was advanced to the remaining distal tip, each secured with interrupted suture of 4-0 absorbable monofilament suture (see diagram). The repair was completed by advancing the remaining proximal tip to the distal spatulation over a 16 F silastic catheter that was maintained for 2.5 weeks. Following catheter removal at the time of post op VCUG, all patients were followed at 3, 6, and 12 months thereafter with AUASS and complex uroflow. Cystoscopy was performed in cases of LUTS or complex uroflow of 15 ml/sec or less. RESULTS: All patients demonstrated patency upon catheter removal. With a follow-up of 12 to 48 months, 3 patients had either significant luts or a marginal uroflow warranting cystoscopy, of which all had a patent urethra accommodating a 16 F cystoscope without evidence of stricture recurrence. CONCLUSIONS: "Z" anastomotic repair can be performed for bulbar urethral strictures without urethral division with previously described benefits of a single dorsal incision of the stricture followed by primary repair using available tissue. The preservation of the bulbar tissue and vasculature may allow for improved urethral perfusion.
Journal of Surgical Research, Feb 1, 2014
Gastroenterology, May 1, 2012
Introduction The optimal timing of primary and metastatic tumor management in patients with synch... more Introduction The optimal timing of primary and metastatic tumor management in patients with synchronous hepatic colorectal metastases remains controversial. We aimed to compare perioperative outcomes of simultaneous colorectal/liver resection (SCLR) with isolated resections utilizing a national clinical database. Methods NSQIP data from 2005 to 2009 were examined to construct risk-adjusted generalized linear models and to calculate group-specific predicted estimates. These were used to compare 30-day perioperative outcomes among patients undergoing SCLR with colorectal (CR) and liver resections (LR) only in patients with metastatic colorectal cancer. Results A total of 3,983 patients were identified, who underwent SCLR (192), LR (1,857), or CR (1,934). Rectal resection was performed in 45 (23.4 %) SCLR patients and 269 (13.9 %) CR patients (p<0.001). Major hepatectomy was performed in 69 (35.9 %) SCLR patients and 774 (41.7 %) LR patients (p00.12).
American Journal of Infection Control, Mar 1, 2017
We performed a study to understand common practices in surgical site hair removal and barriers to... more We performed a study to understand common practices in surgical site hair removal and barriers to guideline compliance in surgical site hair removal. We found most health care providers in the United States do not remove hair outside of the operating room. Our findings reveal minimizing hair dispersal in the operating room, including improved and innovative ways for collecting clipped loose hair, is a significant area for improvement in surgical quality and health care-acquired infection prevention.
Journal of Gastrointestinal Surgery, Jan 11, 2019
Background Controversy exists over the use of adjuvant chemotherapy for locally advanced (stages ... more Background Controversy exists over the use of adjuvant chemotherapy for locally advanced (stages II-III) rectal cancer (LARC) patients who demonstrate pathologic complete response (pCR) following neoadjuvant chemoradiation. We conducted a retrospective analysis to determine whether adjuvant chemotherapy imparts survival benefit among this population. Methods The National Cancer Database (NCDB) was queried to identify LARC patients with pCR following neoadjuvant chemoradiation. The cohort was stratified by receipt of adjuvant chemotherapy. Multiple imputation and a Cox proportional hazards model were employed to estimate the effect of adjuvant chemotherapy on overall survival. Results There were 24,418 patients identified in the NCDB with clinically staged II or III rectal cancer who received neoadjuvant chemoradiation. Of these, 5606 (23.0%) had pCR. Among patients with pCR, 1401 (25%) received adjuvant chemotherapy and 4205 (75%) did not. Patients who received adjuvant chemotherapy were slightly younger, more likely to have private insurance, and more likely to have clinically staged III disease, but did not differ significantly in comparison to patients who did not receive adjuvant chemotherapy with respect to race, sex, facility type, Charlson comorbidity score, histologic tumor grade, procedure type, length of stay, or rate of 30-day readmission following surgery. On adjusted analysis, receipt of adjuvant chemotherapy was associated with a lower risk of death at a given time compared to patients who did not receive adjuvant chemotherapy (HR 0.808; 95% CI 0.679-0.961; p = 0.016). Conclusion Supporting existing NCCN guidelines, the findings from this study suggest that adjuvant chemotherapy improves survival for LARC with pCR following neoadjuvant chemoradiation.
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Papers by Christopher Mantyh