Outcomes of rectal cancer patients who refuse surgery after incomplete clinical response to neoadjuvant therapy.

BACKGROUND AND OBJECTIVES: Total mesorectal excision (TME) remains the standard of care for patients with rectal cancer who have an incomplete response to total neoadjuvant therapy (TNT). A minority of patients will refuse curative intent resection. The aim of this study is to examine the outcomes for these patients. METHODS: A retrospective cohort study of stage 1-3 rectal adenocarcinoma patients who underwent neoadjuvant chemoradiation therapy or TNT at a single institution. Patients either underwent TME, watch-and-wait protocol, or if they refused TME, were counseled and watched (RCW). Clinical outcomes and resource utilization were examined in each group. RESULTS: One hundred seventy-one patients (Male 59%) were included with a median surveillance of 43 months. Twenty-nine patients (17%) refused TME and had shortened overall survival (OS). Twelve patients who refused TME converted to a complete clinical response (cCR) on subsequent staging with a prolonged OS. 92% of these patients had a near cCR at initial staging endoscopy. Increased physician visits and testing was utilized in RCW and WW groups. CONCLUSION: A significant portion of patients convert to cCR and have prolonged OS. Lengthening the time to declare cCR may be considered in select patients, such as those with a near cCR at initial endoscopic staging.

Colorectal cancer in young adults.

The incidence of colorectal cancer in young adults (CRCYAs) is increasing globally, and it is now the third leading cause of cancer death among young adults under 50 years old. The rising incidence is attributed to various emerging risk factors such as genetics, lifestyle factors, and microbiome profiles. Delayed diagnosis and more advanced disease presentation contribute to worse outcomes. A multidisciplinary approach to care is crucial to ensure comprehensive and personalized treatment plans for CRCYA.

A Retrospective Analysis of Patients Undergoing Telemedicine Evaluation in the PreAnesthesia Testing Clinic at H. Lee Moffitt Cancer Center.

BACKGROUND: Telemedicine for preanesthesia evaluation can decrease access disparities by minimizing commuting, time off work, and lifestyle disruptions from frequent medical visits. We report our experience with the first 120 patients undergoing telemedicine preanesthesia evaluation at Moffitt Cancer Center. METHODS: This is a retrospective analysis of 120 patients seen via telemedicine for preanesthesia evaluation compared with an in-person cohort meeting telemedicine criteria had it been available. Telemedicine was conducted from our clinic to a patient's remote location using video conferencing. Clinic criteria were revised to create a tier of eligible patients based on published guidelines and anesthesiologist consensus. RESULTS: Day-of-surgery cancellation rate was 1.67% in the telemedicine versus 0% in the in-person cohort. The two telemedicine group cancellations were unrelated to medical workup, and cancellation rate between the groups was not statistically significant (P = .49). Median round trip distance and time saved by the telemedicine group was 80 miles [range 4; 1180] and 121 minutes [range 16; 1034]. Using the federal mileage rate, the median cost savings was $46 [range $2.30; 678.50] per patient. Patients were similar in gender and race in both groups (P = .23 and .75, respectively), but the in-person cohort was older and had higher American Society of Anesthesiologists physical status classification (P = .0003). CONCLUSIONS: Telemedicine preanesthesia evaluation results in time, distance, and financial savings without increased day-of-surgery cancellations. This is useful in cancer patients who travel significant distances to specialty centers and have a high frequency of health care visits. American Society of Anesthesiologists Physical Status classification and age differences between cohorts indicate possible patient or provider selection bias. Randomized controlled trials will aid in further exploring this technology.

Nonsurgical Management of Acute Appendicitis in Sickle Cell Disease.

A 9-year-old child with sickle cell disease (sickle beta zero thalassemia) was diagnosed to have acute appendicitis during a hospitalization for pain, acute chest syndrome, and exacerbation of asthma. Because of his high surgical risk, his appendicitis was treated nonsurgically, successfully deferring his appendectomy. He remains well after 1 year. This approach should be considered at least in other sickle cell patients with appendicitis, and perhaps other high-risk populations, if not all children with appendicitis.

The impact of interpersonal support, supervisory support, and employee engagement on employee turnover intentions: Differences between financially distressed and highly financially distressed hospitals.

BACKGROUND: Critical access hospitals (CAHs) are small hospitals in rural communities in the United States. Because of changes in rural population demographics, legacy financial obligations, and/or structural issues in the U.S. health care system, many of these institutions are financially distressed. Indeed, many have closed due to their inability to maintain financial viability, resulting in a health care and economic crisis for their communities. Employee recruitment, retention, and turnover are critical to the performance of these hospitals. There is limited empirical study of the factors that influence turnover in such institutions. PURPOSE: The primary purpose of the study was to study relationships between interpersonal support, supervisory support, employee engagement, and employee turnover intentions in CAHs. A secondary purpose was to study how financial distress affects these relationships. METHODOLOGY: Based on a survey of CAH employees (n = 218), the article utilizes mediated moderation analysis of a structural equation model. RESULTS: Interpersonal support and supervisory support are positively associated with employee engagement, whereas employee engagement mediates the relationships between both interpersonal support and supervisory support and employee turnover intentions. Statistically significant differences are found between these relationships in financially distressed and highly financially distressed institutions. CONCLUSIONS: Our results are consistent with the social exchange theory upon which our hypotheses and model are built and demonstrate the value of using the degree of organizational financial distress as a contextual variable when studying motivational factors influencing employee turnover intentions. PRACTICAL IMPLICATIONS: In addition to advancing management theory as applied in the CAH context, our study presents the practical insight that employee perceptions of their employer's financial condition should be considered when organizations develop employee retention strategies. Specifically, employee engagement strategies appear to be of greater value in the case of highly financially distressed organizations, whereas supervisory support seems more effective in financially distressed organizations.

An endoscopic mucosal grading system is predictive of leak in stapled rectal anastomoses.

BACKGROUND: Anastomotic leak is a devastating postoperative complication following rectal anastomoses associated with significant clinical and oncological implications. As a result, there is a need for novel intraoperative methods that will help predict anastomotic leak. METHODS: From 2011 to 2014, patient undergoing rectal anastomoses by colorectal surgeons at our institution underwent prospective application of intraoperative flexible endoscopy with mucosal grading. Retrospective review of patient medical records was performed. After creation of the colorectal anastomosis, application of a three-tier endoscopic mucosal grading system occurred. Grade 1 was defined as circumferentially normal appearing peri-anastomotic mucosa. Grade 2 was defined as ischemia or congestion involving <30% of either the colon or rectal mucosa. Grade 3 was defined as ischemia or congestion involving >30% of the colon or rectal mucosa or ischemia/congestion involving both sides of the staple line. RESULTS: From 2011 to 2014, a total of 106 patients were reviewed. Grade 1 anastomoses were created in 92 (86.7%) patients and Grade 2 anastomoses were created in 10 (9.4%) patients. All 4 (3.8%) Grade 3 patients underwent immediate intraoperative anastomosis takedown and re-creation, with subsequent re-classification as Grade 1. Demographic and comorbidity data were similar between Grade 1 and Grade 2 patients. Anastomotic leak rate for the entire cohort was 12.2%. Grade 1 patients demonstrated a leak rate of 9.4% (9/96) and Grade 2 patients demonstrated a leak rate of 40% (4/10). Multivariate logistic regression associated Grade 2 classification with an increased risk of anastomotic leak (OR 4.09, 95% CI 1.21-13.63, P = 0.023). CONCLUSION: Endoscopic mucosal grading is a feasible intraoperative technique that has a role following creation of a rectal anastomosis. Identification of a Grade 2 or Grade 3 anastomosis should provoke strong consideration for immediate intraoperative revision.

Comparison of open, laparoscopic, and robotic approaches for total abdominal colectomy.

BACKGROUND: The utilization of minimally invasive surgery is increasing in colorectal surgery. We sought to compare the outcomes of patients who underwent elective open, laparoscopic, and robotic total abdominal colectomy. METHODS: The NIS database was used to examine the clinical data of patients who underwent an elective total colectomy procedure during 2009-2012. Multivariate regression analysis was performed to compare the three surgical approaches. RESULTS: We sampled a total of 26,721 patients who underwent elective total colectomy. Of these, 16,780 (62.8 %) had an open operation, while 9934 (37.2 %) had a minimally invasive approach (9614 laparoscopic surgery, and 326 robotic surgery). The most common indication for an operation was ulcerative colitis (31 %). Patients who underwent open surgery had significantly higher mortality and morbidity compared to laparoscopic (AOR 2.48, 1.30, P < 0.01) and robotic approaches (AOR 1.04, 1.30, P < 0.01 and P = 0.04, respectively). There was no significant difference in mortality and morbidity between the laparoscopic and robotic approaches (AOR 0.96, 1.03, P = 0.10, P = 0.78). However, conversion rate of laparoscopic surgery to open was significantly higher than that of robotic approach (13.3 vs. 1.5 %, P < 0.01). Patients who underwent laparoscopic surgery had significantly lower total hospital charges compared to patients who underwent open surgery (mean difference = $21,489, P < 0.01). Also, total hospital charges for a robotic approach were significantly higher than for a laparoscopic approach (mean difference = $15,595, P < 0.01). CONCLUSION: Minimally invasive approaches to total colectomy are safe, with the advantage of lower mortality and morbidity compared to an open approach. Although there was no significant difference in the morbidity between minimally invasive approaches, robotic surgery had a significantly lower conversion rate compared to laparoscopic approach. Total hospital charges are significantly higher in robotic surgery compared to laparoscopic approach.

Laparoscopic right hemicolectomy: short- and long-term outcomes of intracorporeal versus extracorporeal anastomosis.

BACKGROUND: The use of laparoscopy for right hemicolectomy has gained popularity allowing the option of a totally laparoscopic intracorporeal anastomosis (IA) for intestinal reconstruction. This technique may alleviate some of the technical limitations that a surgeon faces with a laparoscopic-assisted extracorporeal anastomosis (EA). METHODS: A retrospective chart review of 195 consecutive patients who underwent laparoscopic right hemicolectomy by four colorectal surgeons at three institutions from March 2005 to June 2014 was performed. Multivariate regression analysis was used to compare postoperative and oncologic outcomes. RESULTS: A total of 195 patients underwent laparoscopic right hemicolectomy over the study period, with 86 (44 %) patients receiving IA and 109 (56 %) patients receiving an EA. The most common indication for surgery in both groups was cancer: 56 (65 %) of IA cases and 57 (52 %) of EA cases. IA had a significantly higher rate of minor complications but no difference in serious complications compared to EA. Conversion to open resection was higher in EA. Using multivariate analysis to compare IA versus EA, there was no significant difference in length of stay, return of bowel function, risk of anastomotic leak, risk of intraabdominal abscess or risk of wound complications. Amongst cancer resections, there was no significant difference in the median number of lymph nodes harvested (18 LNs in IA group vs. 19 LNs in EA group, P > 0.05). There was also no significant difference in overall survival and disease-free survival at 5.7 years between the two groups. CONCLUSIONS: IA in laparoscopic right hemicolectomy is associated with similar postoperative and oncologic outcomes compared to EA. IA may possess advantages in terms of conversion and flexibility of specimen extraction, but this is counterbalanced by a higher incidence of minor complications. These findings suggest that IA represents a valid technique in the arsenal of the experienced colorectal surgeon without compromising outcomes.

Risk factors for prolonged ileus following colon surgery.

BACKGROUND: Prolonged ileus is one of the most common postoperative complications after colorectal surgery. We sought to investigate the predictors of prolonged ileus following elective colon resections procedures. METHODS: The national participant user files of NSQIP databases were utilized to examine the clinical outcomes of patients undergoing elective colon resection during 2012-2013. Multivariate regression analysis was performed to investigate predictors of prolonged ileus. Prolonged ileus was defined as no return of bowel function in 7 days. RESULTS: We sampled a total of 27,560 patients who underwent colon resections; of these, 3497 (12.7%) patients had prolonged ileus. Patients with ileocolonic anastomosis (ICA) had a significantly higher rate of prolonged ileus compared to patients with colorectal anastomosis (CRA) (15 vs. 11.5%, AOR 1.25, P < 0.01). Prolonged ileus was significantly associated with intra-abdominal infections (13 vs. 2.8%, AOR 2.56, P < 0.01) and anastomotic leakage (12 vs. 2.4%, AOR 2.50, P < 0.01). Factors such as preoperative sepsis (AOR 1.63, P < 0.01), disseminated cancer (AOR 1.24, P = 0.01), and chronic obstructive pulmonary disease (AOR 1.27, P = 0.02) were associated with an increased risk of prolonged ileus, whereas oral antibiotic bowel preparation (AOR 0.77, P < 0.01) and laparoscopic surgery (AOR 0.51, P < 0.01) are associated with decreased prolonged ileus risk. CONCLUSIONS: Prolonged ileus is a common condition following colon resection, with an incidence of 12.7%. Among colon surgeries, colectomy with ICA resulted in the highest rate of postoperative prolonged ileus. Prolonged ileus is positively associated with anastomotic leak and intra-abdominal infections; thus, a high index of suspicion must be had in all patients with prolonged postoperative ileus.

Post-Hospital Discharge Venous Thromboembolism in Colorectal Surgery.

BACKGROUND: There are limited data regarding the criteria for prophylactic treatment of venous thromboembolism (VTE) after hospital discharge. We sought to identify risk factors of post-hospital discharge VTE events following colorectal surgery. METHODS: The NSQIP database was utilized to examine patients developed VTE after hospital discharge following colorectal surgery during 2005-2013. Multivariate analysis using logistic regression was performed to quantify risk factors of VTE after discharge. RESULTS: We evaluated a total of 219,477 patients underwent colorectal resections. The overall incidence of VTE was 2.1 % (4556). 33.8 % (1541) of all VTE events occurred after hospital discharge. The length of postoperative hospitalization had a strong association with post-discharge VTE, with the highest risk in patients who were hospitalized for more than 1 week after operation (AOR 9.08, P < 0.01). Other factors associated with post-discharge VTE included chronic steroid use (AOR 1.81, P < 0.01), stage 4 colorectal cancer (AOR 1.40, P = 0.03), obesity (AOR 1.37, P < 0.01), age >70 (AOR 1.21, P = 0.04), and open surgery (AOR 1.36, P < 0.01). Patients who were hospitalized for more than 1 week after an open colorectal resections had a 12 times higher risk of post-discharge VTE event compared to patients hospitalized less than 4 days after a laparoscopic resection (AOR 12.34, P < 0.01). CONCLUSIONS: VTE is uncommon following colorectal resections; however, a significant proportion occurs after patients are discharged from the hospital (33.8 %). The length of postoperative hospitalization appears to have a strong association with post-discharge VTE. High-risk patients may benefit from continued VTE prophylaxis after discharge.

Surgical site infection impact of pelvic exenteration procedure.

BACKGROUND: We sought to investigate morbidity and infectious complications following pelvic exenteration (PEx) and compare infectious complications of patients undergoing PEx and conventional rectal resections. METHODS: The NSQIP database was utilized to examine the clinical data of patients undergoing elective rectal resections during 2005-2013. Multivariate regression analysis was used to compare postoperative complications of patients who underwent PEx and proctectomy procedure. RESULTS: We sampled a total of 7,950 patients who underwent rectal resection. Of these, 303 (3.8%) patients underwent pelvic exenteration. Mortality, morbidity, and infectious complications of patients who underwent pelvic exenteration were 1.7%, 65.7%, and 42.6%, respectively. Patients who underwent PEx had a significantly higher rate of morbidity (AOR: 2.01, P < 0.01), overall infectious complications (AOR: 1.49, P < 0.01), hemorrhagic complications (AOR: 3.36, P < 0.01), and surgical site infections (SSI) (AOR: 1.23, P = 0.04) compared to patients who underwent proctectomy. Return to operation room (AOR: 4.99, P < 0.01), obesity (AOR: 1.43, P < 0.01), disseminated cancer (AOR: 1.30, P = 0.01) were significantly associated with SSI complications. CONCLUSION: Postoperative morbidity and infectious complication are significantly higher after PEx procedure. Return to operation room, obesity, and disseminated cancer are strongly associated with surgical site infections complications in rectal surgery. Specific consideration to infectious complications is recommended for these patients.

Colorectal surgery in Parkinson's disease--outcomes and predictors of mortality.

PURPOSE: Although diseases of the lower gastrointestinal tract are common in patients with Parkinson's disease, there is a paucity of data regarding postoperative outcomes after colorectal surgery. METHODS: The Nationwide Inpatient Sample database (2007-2011) was utilized to analyze outcomes in patients with Parkinson's disease (PD) undergoing colorectal surgery. Main outcomes were risk-adjusted inpatient morbidity, mortality, hospital charge, and length of hospital stay. RESULTS: A total of 6490 patients were identified. Utilization of laparoscopic surgery in Parkinson's patients has progressively increased in frequency over the latest 5 years analyzed. The most common diagnoses were colorectal malignancy (39 %) and intestinal obstruction (20 %). Right hemicolectomy (37 %) and sigmoidectomy (30 %) were the most common operations. Laparoscopy was used in 18 % of Parkinson's patients and most commonly in the elective setting. 54.3 % of Parkinson's patients had emergency surgery compared to 38.6 % in non-Parkinson's. Overall morbidity and mortality were significantly lower after laparoscopic surgery compared to open (20 vs. 25 % and 2.1 vs. 6.6 %, respectively). Length of stay was significantly shorter (OR -1.86; p < 0.01) for laparoscopic operations, but there were no significant differences in risk-adjusted outcomes between laparoscopic and open groups. CONCLUSION: PD patients have high rates of morbidity and mortality after colorectal surgery; this may be because more than half of all patients in this population undergo emergent surgery. The laparoscopic approach appears to have short-term benefits in this patient population.

Wound Disruption Following Colorectal Operations.

OBJECTIVES: Postoperative wound disruption is associated with high morbidity and mortality. We sought to identify the risk factors and outcomes of wound disruption following colorectal resection. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was used to examine the clinical data of patients who underwent colorectal resection from 2005 to 2013. Multivariate regression analysis was performed to identify risk factors of wound disruption. RESULTS: We sampled a total of 164,297 patients who underwent colorectal resection. Of these, 2073 (1.3 %) had wound disruption. Patients with wound disruption had significantly higher mortality (5.1 vs. 1.9 %, AOR: 1.46, P = 0.01). The highest risk of wound disruption was seen in patients with wound infection (4.8 vs. 0.9 %, AOR: 4.11, P < 0.01). A number of factors are associated with wound disruption such as chronic steroid use (AOR: 1.71, P < 0.01), smoking (AOR: 1.60, P < 0.01), obesity (AOR: 1.57, P < 0.01), operation length more than 3 h (AOR: 1.56, P < 0.01), severe Chronic Obstructive Pulmonary Disease (COPD) (AOR: 1.36, P < 0.01), urgent/emergent admission (AOR: 1.31, P = 0.01), and serum Albumin Level <3 g/dL (AOR: 1.27, P < 0.01). Laparoscopic surgery had significantly lower risk of wound disruption compared to open surgery (AOR: 0.61, P < 0.01). CONCLUSION: Wound disruption occurs in 1.3 % of colorectal resections, and it correlates with mortality of patients. Wound infection is the strongest predictor of wound disruption. Chronic steroid use, obesity, severe COPD, prolonged operation, non-elective admission, and serum albumin level are strongly associated with wound disruption. Utilization of the laparoscopic approach may decrease the risk of wound disruption when possible.

Diverting ileostomy in colorectal surgery: when is it necessary?

PURPOSE: The role of fecal diversion using a loop ileostomy in patients undergoing rectal resection and anastomosis is controversial. There has been conflicting evidence on the perceived benefit vs. the morbidity of a defunctioning stoma. This is a review of the relevant surgical literature evaluating the risks, benefits, and costs of constructing a diverting ileostomy in current colorectal surgical practice. METHODS: Retrospective and prospective articles spanning the past 50 years were reviewed to identify the definition of an anastomotic leak (AL), evaluate risk factors for AL, and assess methods of evaluation of the anastomosis. We then pooled the evidence for and against fecal diversion, the incidence and consequences of stomal complications, and the evidence comparing loop ileostomy vs. loop colostomy as the optimal method of fecal diversion. RESULTS: Evidence shows that despite the fact that fecal diversion does not decrease postoperative mortality, it does significantly decrease the risk of anastomotic leak and the need for urgent reoperation when a leak does occur. Diverting stomas are a low-risk surgical procedure from a technical standpoint but carry substantial postoperative morbidity that can greatly hamper patients' quality of life and recovery. High-risk patients such as those with low colorectal anastomoses (<10 cm from anal verge), colo-anal anastomoses, technically difficult resections, malnutrition, and male patients seem to reap the greatest benefit from fecal diversion. CONCLUSIONS: Fecal diversion is recommended as a selective tool to protect or ameliorate an anastomotic leak after a colorectal anastomosis. It is most beneficial when used selectively in high-risk patients with low pelvic anastomoses that are at an increased risk for AL. New tools are needed to identify patients at high risk for anastomotic failure after anterior resection.

Efficacy of embolotherapy for the treatment of pelvic congestion syndrome: A systematic review.

Pelvic congestion syndrome (PCS) poses a significant health, diagnostic, and economic challenges. Transcatheter embolisation has emerged as a promising treatment for PCS. A systematic review was performed in order to assess the safety and efficacy of transcatheter embolisation in the treatment of PCS. A systematic search of electronic databases was performed using 'PubMed', 'Embase', 'Medline (OVID)', and 'Web of Science', for articles pertaining to efficacy of embolotherapy for the treatment of pelvic congestion syndrome. A total of 25 studies were included in this systematic review with a combined total of 2038 patients. All patients included were female with a mean average age of 37.65 (31-51). Of the 25 studies, 18/25 studies reported pre- and post-procedural pelvic pain outcomes using a visual analogue scale (VAS). All studies showed a reduction in VAS post-procedure. Transcatheter embolisation had a high technical success rate (94%) and an overall complication rate of 9.0%, of which 10.4% were major and 89.6% were minor. Fifteen out of 19 (78.9%) major complications required a subsequent intervention. Transcatheter embolisation using various techniques is effective and safe in treating PCS. A low quality of evidence limits the currently available literature; however, embolisation has shown to improve symptoms in the majority of patients with low complication rates and recurrence rates.

Who should get a right colectomy in low-grade appendiceal adenocarcinomas? Association of lymphovascular invasion and nodal metastases.

BACKGROUND: There is variation in the probability of nodal metastases from low-grade appendiceal adenocarcinomas, and the role of right colectomy is unclear. We aimed to define the prevalence and utility of lymphovascular invasion in predicting the risk of nodal metastases to help stratify patients who may benefit from right hemicolectomy. METHODS: Patients with nonmetastatic low-grade appendiceal adenocarcinomas were identified from the National Cancer Database (2010-2017). The primary outcome was probability of nodal metastases. Logistic regression was used to identify independent predictors of nodal metastases. A 4-tier risk model-the COH Composite Score-was calculated by assigning 1 point each for a high-risk feature (lymphovascular invasion, T3/T4 T stage, or nonmucinous histology). Survival analysis was performed using the Kaplan-Meier method. Multivariate Cox regression analysis was used to identify independent predictors of survival. RESULTS: A total of 1,303 patients with nonmetastatic low-grade appendiceal adenocarcinomas (64.2% mucinous) were identified. Of the 1,133 patients with known lymphovascular invasion status, 78 (6.9%) were lymphovascular invasion positive. In multivariate analysis, lymphovascular invasion was independently associated with nodal metastases (odds ratio, 8.68; P < .001). Overall accuracy of lymphovascular invasion in predicting nodal metastases was 86%. The COH Composite Score stratified patients in 4 categories with increasing risk of nodal metastases and incrementally worse survival. For patients with the COH Composite Score of 0 (12%), the nodal metastasis rate was 3.1%, and a right hemicolectomy in this group did not improve survival. CONCLUSION: The presence of lymphovascular invasion is strongly predictive of nodal metastases. Lymphovascular invasion as part of the COH Composite Score may help guide the extent of surgery in low-grade appendiceal adenocarcinomas.

The effect of a sexual abuse history on symptoms and anorectal physiology findings in patients presenting to a colorectal pelvic floor service.

BACKGROUND: Studies report that 12%-23% of patients with functional anorectal disorders have a history of sexual abuse (SA). This article aims to assess whether there is a difference in symptom severity, quality of life or anorectal physiology findings in female patients presenting to a colorectal pelvic floor service with and without a history of sexual abuse. METHODS: A retrospective analysis of all female patients attending a single tertiary pelvic floor unit for faecal incontinence or constipation between 2017 and 2019 was performed. Patients were divided into two groups depending on the presence or absence of a volunteered history of sexual abuse. Validated quality of life and symptom severity scores, along with anorectal physiology studies were analysed and compared between the two groups. RESULTS: There were 148 patients included in the study period and 17% reported a history of SA. There was no statistically significant difference in symptom severity, quality of life scores or anorectal physiology studies between those with and without a history of SA. CONCLUSION: In female patients seeking management for defaecatory symptoms, those who have reported a history of SA did not demonstrate any significant difference in symptom severity, quality of life or physiological measures when compared to those without a history of SA.

n-Type transition metal oxide as a hole extraction layer in PbS quantum dot solar cells.

The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoO(x)) and vanadium oxide (V(2)O(x)) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoO(x) HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the case of Au contacting the PbS quantum dot (QD) layer directly. We find the acting mechanism of the hole extraction layer to be a dipole formed at the MoO(x) and PbS interface enhancing band bending to allow efficient hole extraction from the valence band of the PbS layer by MoO(x). The carrier transport to the metal anode is likely enhanced through shallow gap states in the MoO(x) layer.

Comparing multiple exciton generation in quantum dots to impact ionization in bulk semiconductors: implications for enhancement of solar energy conversion.

Multiple exciton generation (MEG) in quantum dots (QDs) and impact ionization (II) in bulk semiconductors are processes that describe producing more than one electron-hole pair per absorbed photon. We derive expressions for the proper way to compare MEG in QDs with II in bulk semiconductors and argue that there are important differences in the photophysics between bulk semiconductors and QDs. Our analysis demonstrates that the fundamental unit of energy required to produce each electron-hole pair in a given QD is the band gap energy. We find that the efficiency of the multiplication process increases by at least 2 in PbSe QDs compared to bulk PbSe, while the competition between cooling and multiplication favors multiplication by a factor of 3 in QDs. We also demonstrate that power conversion efficiencies in QD solar cells exhibiting MEG can greatly exceed conversion efficiencies of their bulk counterparts, especially if the MEG threshold energy can be reduced toward twice the QD band gap energy, which requires a further increase in the MEG efficiency. Finally, we discuss the research challenges associated with achieving the maximum benefit of MEG in solar energy conversion since we show the threshold and efficiency are mathematically related.

Update on the management of sigmoid diverticulitis.

Diverticular disease and diverticulitis are the most common non-cancerous pathology of the colon. It has traditionally been considered a disease of the elderly and associated with cultural and dietary habits. There has been a growing evolution in our understanding and the treatment guidelines for this disease. To provide an updated review of the epidemiology, pathogenesis, classification and highlight changes in the medical and surgical management of diverticulitis. Diverticulitis is increasingly being seen in young patients (< 50 years). Genetic contributions to diverticulitis may be larger than previously thought. Potential similarities and overlap with inflammatory bowel disease and irritable bowel syndrome exist. Computed tomography imaging represents the standard to classify the severity of diverticulitis. Modifications to the traditional Hinchey classification might serve to better delineate mild and intermediate forms as well as better classify chronic presentations of diverticulitis. Non-operative management is primarily based on antibiotics and supportive measures, but antibiotics may be omitted in mild cases. Interval colonoscopy remains advisable after an acute attack, particularly after a complicated form. Acute surgery is needed for the most severe as well as refractory cases, whereas elective resections are individualized and should be considered for chronic, smoldering, or recurrent forms and respective complications (stricture, fistula, etc.) and for patients with factors highly predictive of recurrent attacks. Diverticulitis is no longer a disease of the elderly. Our evolving understanding of diverticulitis as a clinical entity has led into a more nuanced approach in both the medical and surgical management of this common disease. Non-surgical management remains the appropriate treatment for greater than 70% of patients. In individuals with non-relenting, persistent, or recurrent symptoms and those with complicated disease and sequelae, a segmental colectomy remains the most effective surgical treatment in the acute, chronic, or elective-prophylactic setting.