Evaluating postoperative hernia incidence and risk factors following pelvic exenteration.

Pelvic exenteration (PE) is a technically challenging surgical procedure. More recently, quality of life and survivorship following PEs are being increasingly acknowledged as important patient outcomes. This includes evaluating major long-term complications such as hernias, defined as the protrusion of internal organs through a facial defect (The PelvEx Collaborative in Br J Surg 109:1251-1263, 2022), for which there is currently limited literature. The aim of this paper is to ascertain the incidence and risk factors for postoperative hernia formation among our PE cohort managed at a quaternary centre. METHOD: A retrospective cohort study examining hernia formation following PE for locally advanced rectal carcinoma and locally recurrent rectal carcinoma between June 2010 and August 2022 at a quaternary cancer centre was performed. Baseline data evaluating patient characteristics, surgical techniques and outcomes was collated among a PE cohort of 243 patients. Postoperative hernia incidence was evaluated via independent radiological screening and clinical examination. RESULTS: A total of 79 patients (32.5%) were identified as having developed a hernia. Expectantly, those undergoing flap reconstruction had a lower incidence of postoperative hernias. Of the 79 patients who developed postoperative hernias, 16.5% reported symptoms with the most common symptom reported being pain. Reintervention was required in 18 patients (23%), all of which were operative. CONCLUSION: This study found over one-third of PE patients developed a hernia postoperatively. This paper highlights the importance of careful perioperative planning and optimization of patients to minimize morbidity.

Validation of a Field-Portable, Handheld Real-Time PCR System for Detecting Pseudogymnoascus destructans, the Causative Agent of White-Nose Syndrome in Bats.

White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans, has decimated bat populations across North America. Despite ongoing management programs, WNS continues to expand into new populations, including in US states previously thought to be free from the pathogen and disease. This expansion highlights a growing need for surveillance tools that can be used to enhance existing monitoring programs and support the early detection of P. destructans in new areas. We evaluated the feasibility of using a handheld, field-portable, real-time (quantitative) PCR (qPCR) thermocycler known as the Biomeme two3 and the associated field-based nucleic acid extraction kit and assay reagents for the detection of P. destructans in little brown bats (Myotis lucifugus). Results from the field-based protocol using the Biomeme platform were compared with those from a commonly used laboratory-based qPCR protocol. When using dilutions of known conidia concentrations, the lowest detectable concentration with the laboratory-based approach was 108.8 conidia/mL, compared with 1,087.5 conidia/mL (10 times higher, i.e., one fewer 10× dilution) using the field-based approach. Further comparisons using field samples suggest a high level of concordance between the two protocols, with positive and negative agreements of 98.2% and 100% respectively. The cycle threshold values were marginally higher for most samples using the field-based protocol. These results are an important step in establishing and validating a rapid, field-assessable detection platform for P. destructans, which is urgently needed to improve the surveillance and monitoring capacity for WNS and support on-the-ground management and response efforts.

SURVEILLANCE OF BATS IN THE UNITED STATES FOR SARS-COV-2 AND OTHER CORONAVIRUSES.

Bat coronaviruses (CoVs) are extremely prevalent throughout the globe and exhibit a wide range of genetic diversity. Currently, little is known about the susceptibility of New World bats to severe acute respiratory syndrome-2 (SARS-CoV-2), the causative agent of COVID-19. Also, there is limited information about the genetic diversity of other CoVs in the New World bats. The determination of genetic diversity of bat CoVs through continuous surveillance is essential to predict and mitigate the emergence of new CoVs and their impacts on the health of both humans and animals. In this study, 491 guano specimens collected from New World bats and 37 specimens collected from Old World bats during July 2020 to July 2021 were tested for SARS-COV-2 and other CoVs using a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) panel and pan-coronavirus PCR that target a highly conserved region of CoVs. No evidence of SARS-CoV-2 was found in the tested specimens. An alpha CoV was detected in a single specimen from a big brown bat (Eptesicus fuscus). This information was used by wildlife agencies and rehabilitation facilities to permit the release of bats during the pandemic while mitigating the risk of spreading SARS-CoV-2 among North American bats and other wild animal populations.

Distinct changes in the colonic microbiome associated with acute diverticulitis.

AIM: The pathogenesis of acute diverticulitis (AD) remains incompletely understood, despite it being one of the most common gastrointestinal conditions worldwide. The aim of this study was to investigate the role of the colonic microbiome in the pathogenesis of AD. METHOD: A prospective case-control study was performed, comparing the microbiome of AD patients with that of controls, using 16S rRNA sequencing of rectal swab samples. RESULTS: The microbiome of individuals with AD showed lower diversity than that of controls. There were significant compositional differences observed, with a lower abundance of commensal bacterial families and genera such as Lachnospiraceae, Ruminococcus and Faecalibacterium in AD patients compared with controls, and there was an increase in several genera with known pathogenic roles including Fusobacteria, Prevotella and Paraprevotella. CONCLUSION: This is the largest study to date to examine the microbiota of AD patients, and adds evidence to the proposed hypothesis that alterations in the colonic microbiome play a role in the pathogenesis of AD.

Bat Red Blood Cells Express Nucleic Acid-Sensing Receptors and Bind RNA and DNA.

RBCs demonstrate immunomodulatory capabilities through the expression of nucleic acid sensors. However, little is known about bat RBCs, and no studies have examined the immune function of bat erythrocytes. In this study, we show that bat RBCs express the nucleic acid-sensing TLRs TLR7 and TLR9 and bind the nucleic acid ligands, ssRNA, and CpG DNA. Collectively, these data suggest that, like human RBCs, bat erythrocytes possess immune function and may be reservoirs for nucleic acids. These findings provide unique insight into bat immunity and may uncover potential mechanisms by which virulent pathogens of humans are concealed in bats.

The impact of prolonged delay to loop ileostomy closure on postoperative morbidity and hospital stay: A retrospective cohort study.

AIM: There is increasing evidence that delayed loop ileostomy closure is associated with an increase in postoperative morbidity. In the context of a publicly funded health service with constrained theatre access, we review the impact of delay in loop ileostomy closure. METHOD: A retrospective cohort study of patients undergoing loop ileostomy closure at the Dunedin Public Hospital between 2000-2017 was performed. Cases and complications were identified from the prospectively maintained Otago Clinical Audit database. Patient demographics, ASA score, indications for ileostomy, reasons for delay in closure, length of stay (LOS) after ileostomy closure and complications were collected. LOS and overall complication rate were assessed using univariable and multivariable analyses. RESULTS: A total of 292 patients were included in the study, of whom 74 (25.3%) were waiting for longer than 12 months for ileostomy closure. The overall complication rate was 21.5%. This was 8% up to 90 days, 20% between 90-360 days, 28% between 360-720 days and 54% after 720 days. Delay was associated with an increased risk of any complication (RR 1.06 for every 30 days with stoma, p < 0.001), including Ileus (OR [95% CI] 1.06 [1.00-1.11], p = 0.024). Overall mean LOS was 5.9 days (range 1-63), being 4.6 days up to 180 days, 5.6 between 180-720 days and 8.7 after 720 days. LOS significantly increased with increasing stoma duration (p = 0.04). CONCLUSION: Increasing time with loop ileostomy is detrimental for patients, being associated with an increase in complication rates, and is detrimental for hospitals due to increased length of stay. Resources should be allocated for timely closure of loop ileostomies.

Rectal swabs are a reliable method of assessing the colonic microbiome.

BACKGROUND: Advances in genome sequencing have enabled detailed microbiome analysis; however, the ideal specimen type for sequencing is yet to be determined. Rectal swabs may offer a rapid and convenient modality for colonic microbiome analysis. The aim of this study is to evaluate the use of rectal swabs compared to faecal specimens. METHODS AND RESULTS: Twenty health professionals participated in this study and provided a faecal specimen, a self-collected rectal swab and a rectal swab taken by a clinician. DNA was extracted and 16S rRNA gene sequencing was carried out for microbiome analysis. Alpha diversity was higher in swabs compared to faecal specimens; however, the difference was only significant when comparing clinician-obtained swabs to faeces. Analysis of beta diversity consistently showed that few taxa were affected by sample type. We found sample type accounted for only 6.8% of community variation (R2 = 0.067, p < 0.001, permanova). Notably, there were only six genera identified in clinician-obtained swabs that were not also found in the self-taken swabs. CONCLUSIONS: Both self-collected and clinician obtained rectal swabs are a reliable method of analysing the colonic microbiome. Obtaining specimens for microbiome analysis is often time-critical due to therapy, such as antibiotics, influencing the microbiome. Rectal swabs are shown to be a valid and convenient modality for microbiome analysis.

Acute Diverticulitis in Young Patients: A Review of the Changing Epidemiology and Etiology.

Acute diverticulitis is one of the leading gastrointestinal causes for hospitalization. The incidence of acute diverticulitis has been increasing in recent years, especially in patients under 50 years old. Historically, acute diverticulitis in younger patients was felt to represent a separate entity, being more virulent and associated with a higher rate of recurrence. Accordingly, young patients were often managed differently to older counterparts. Our understanding of the natural history of this condition has evolved, and current clinical practice guidelines suggest age should not alter management. The purpose of this review is to evaluate the changing epidemiology of acute diverticulitis, consider potential explanations for the observed increased incidence in younger patients, as well as review the natural history of acute diverticulitis in the younger population.

The Epidemiology and Etiology of Right-Sided Colonic Diverticulosis: A Review.

Diverticulosis of the colon is a common condition in Western countries and most patients will remain asymptomatic, but some will present with symptoms of acute diverticulitis or bleeding. Our understanding of diverticulosis is evolving but is mostly derived from diverticulosis affecting the left-sided colon. In contrast, right-sided colonic diverticulosis (RCD) is more commonly seen in Asian countries but is much less common overall. Based on the marked differences in epidemiology, it is commonly thought that these are 2 distinct disease processes. A review of the literature describing the epidemiology and etiology of RCD was performed, with a comparison to the current understanding of left-sided diverticulosis. RCD is becoming increasingly common. The epidemiology of RCD shows it to be a mostly acquired condition, and not congenital as previously thought. Many factors in the etiology of RCD are similar to that seen in left-sided diverticulosis, with a few variations. It is therefore likely that most cases of RCD represent the same disease process that is seen in the left colon.

The prevalence of right-sided colonic diverticulosis in a New Zealand population.

BACKGROUND: Once considered to be a congenital condition, the epidemiology of right-sided colonic diverticulosis (RCD) is evolving. Acute diverticulitis (AD) is a complication of RCD which is frequently misdiagnosed as appendicitis, resulting in unnecessary surgery, as there is strong evidence supporting medical management for right-sided AD. In general, the incidence of AD correlates with the prevalence of RCD, which shows marked geographic variation. Few data reporting RCD prevalence come from Western countries, so the aim of this study is to define the prevalence of RCD in a New Zealand population. METHODS: Independent review of the imaging from 1000 consecutive patients undergoing a computed tomography Kidney/Ureter/Bladder scan for suspected urolithiasis at Christchurch Hospital between January and November 2017 was undertaken, to determine the presence or absence, and distribution of colonic diverticulosis. Patients were excluded if they had a history of colonic resection, known IBD, or were less than 18-years old. RESULTS: Thirty-one patients were excluded, leaving 969 eligible patients. Overall, 95 patients (9.8%) had RCD identified. The prevalence of RCD increased significantly with advancing age, being present in 2.3% of those aged 18-29, increasing to 20.3% in those greater than 70-years old (p < 0.001). CONCLUSION: The prevalence of RCD in a New Zealand population is relatively high and increases significantly with age. This adds support to the role of cross-sectional imaging in the evaluation of suspected appendicitis, to exclude right-sided AD. The association with advancing age supports RCD being an acquired condition rather than a congenital condition as was previously thought.

Extension for Community Healthcare Outcomes (ECHO) Telementoring in the Military: Where We Are Now, Opportunities and Challenges.

INTRODUCTION: In collaboration with the ECHO (Extension for Community Healthcare Outcomes) Institute since 2012, the Army, Navy, and Air Force have developed medical teleECHO programs to address various health and safety issues affecting military personnel. This article describes and compares the current state of military teleECHOs as well as the growth and change over time. MATERIALS AND METHODS: This study evaluated continuing education units (CEUs) offered, average session attendance, and number of spoke sites for current military teleECHO programs across the service branches. RESULTS: Between 2012 and 2019, the military teleECHO initiative grew from one program to seven different teleECHO programs, covering topics from pain to diabetes to amputee care. Military ECHOs now provide training to 10 countries and 27 states in the United States. Between October 2018 and September 2019, the military ECHO programs provided a total of 51,769 continuing medical education (CME) hours to a total of 3,575 attendees from 223 spoke sites. CONCLUSIONS: The military has successfully used the ECHO model to improve the health and safety of active-duty military, retirees, and dependents.

Evaluation of a real-time RT-PCR panel for detection of SARS-CoV-2 in bat guano.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which is an ongoing global health concern. The exact source of the virus has not been identified, but it is believed that this novel coronavirus originated in animals; bats in particular have been implicated as the primary reservoir of the virus. SARS-CoV-2 can also be transmitted from humans to other animals, including tigers, cats, and mink. Consequently, infected people who work directly with bats could transfer the virus to a wild North American bat, resulting in a new natural reservoir for the virus, and lead to new outbreaks of human disease. We evaluated a reverse-transcription real-time PCR panel for detection of SARS-CoV-2 in bat guano. We found the panel to be highly specific for SARS-CoV-2, and able to detect the virus in bat guano samples spiked with SARS-CoV-2 viral RNA. Our panel could be utilized by wildlife agencies to test bats in rehabilitation facilities prior to their release to the wild, minimizing the risk of spreading this virus to wild bat populations.

Influence of obesity on the risk of recurrent acute diverticulitis.

BACKGROUND: Acute diverticulitis (AD) is a common surgical problem with increasing incidence. Obesity has become epidemic in western countries. Obesity has been shown to increase the risk of developing AD; however, little is known about its influence on the risk of recurrence. The decision to perform elective surgical resection to reduce the risk of recurrent AD is made on an individual basis considering perceived risk of recurrence weighed against patient comorbidity. The aim of this study is to assess whether obesity affects the likelihood of developing recurrent AD. METHODS: A retrospective audit was conducted of all admissions with AD to a tertiary centre between 1998 and 2010. Medical records were reviewed and patients with an index presentation with AD included in the analysis. Imaging was used to calculate body mass index (BMI) for assessment of obesity. Follow-up was for a minimum of 3 years from admission. RESULTS: A total of 1299 patients were admitted with an index presentation of AD in the study period. 18.3% overall had recurrent AD, all of whom had confirmation on imaging. Computed tomography was used to calculate BMI in 849 patients, of whom 470 (55.4%) were considered obese (BMI >30). The likelihood of recurrent AD was not significantly different in obese patients compared to their non-obese counterparts (P = 0.2473). CONCLUSION: While obesity increases the risk of developing AD overall, it does not appear to increase the likelihood of developing recurrent AD. This has implications for risk stratification when considering surgical resection to prevent recurrent AD.

Endoscopic large balloon sphincteroplasty is a useful, safe adjunct for difficult to treat choledocholithiasis.

BACKGROUND: The aim of this study was to assess the safety and efficacy of large balloon sphincteroplasty when used in conjunction with endoscopic biliary sphincterotomy during endoscopic retrograde cholangiopancreatography (ERCP) for therapy of choledocholithiasis. METHODS: A retrospective audit of all ERCP's performed for choledocholithiasis between January 2012 and October 2013 at one institution was performed. Procedures that utilized large balloon sphincteroplasty were compared with those underwent standard endoscopic stone extraction. Outcomes including stone clearance rate for the individual procedure type, post-ERCP complications and need for surgical exploration of the bile duct were documented. RESULTS: A total of 346 procedures on 306 patients that met the inclusion criteria were identified. Fifty-four (15.6%) procedures included large balloon sphincteroplasty and were compared with 292 (84.4%) procedures that used standard balloon extraction techniques. Despite those patients in the large balloon sphincteroplasty group having a higher rate of previous ERCP (33.3% versus 19.5%, P = 0.031) and a larger proportion of patients with stones greater than 10 mm (40.3% versus 11.3%, P < 0.001), the overall initial clearance rate was similar at 83%. Ultimately, only 14 out of 306 (4.6%) of all patients required surgical intervention. There was no significant difference in the rate of post-ERCP pancreatitis between the two groups (5.6% versus 3.8%, P = 0.466). CONCLUSION: Large balloon sphincteroplasty of the sphincter of Oddi is a safe and effective adjunct to endoscopic biliary sphincterotomy in difficult to treat choledocholithiasis. The current study demonstrated large balloon sphincteroplasty did not result in more complications despite a tendency to being used for larger stones.

Cystoprostatectomy versus prostatectomy alone for locally advanced or recurrent pelvic cancer.

BACKGROUND: There is minimal published data evaluating the oncological outcome of rectal resection with prostatectomy alone versus rectal resection with cystoprostatectomy in patients undergoing pelvic exenteration for locally advanced or recurrent pelvic cancer. This study aims to evaluate the oncological and functional outcomes of performing rectal resection with prostatectomy alone compared with rectal resection with cystoprostatectomy in patients undergoing pelvic exenteration. METHODS: Consecutive patients undergoing pelvic exenteration for locally advanced or recurrent pelvic cancer between 1998 and 2012 were identified from a prospectively maintained database. Patients undergoing rectal resection with prostatectomy alone were compared with a control group who underwent rectal resection with cystoprostatectomy and urostomy formation. The primary outcome was overall survival. Secondary outcomes analysed in the prostatectomy group included completeness of resection, continence and erectile function. RESULTS: Eleven rectal resections with prostatectomy were compared with 20 rectal resections with cystoprostatectomy. R0 resection was achieved in 73 and 65% respectively. There was no difference in overall survival (P = 0.40). Urinary continence was achieved in 36% of prostatectomy alone patients, while 27% experienced mild incontinence. Erectile function was poor, with only one patient able to maintain normal erections. CONCLUSION: In appropriately selected patients with invasive pelvic tumours, rectal resection with prostatectomy alone provides adequate oncological outcomes. The ability to achieve an R0 resection was not compromised and overall survival is comparable with cystoprostatectomy. Urinary function is reasonable in most patients, although sexual function is compromised in almost all.

Metastatic renal cell carcinoma--an unexpected finding after laparoscopic cholecystectomy.

Tumours metastasising to the gallbladder from other sites are rare; we aim to present a case of this unusual site of metastasis and give an overview of the current literature surrounding it. A case of renal cell carcinoma (RCC) with gallbladder metastasis is presented, along with a brief summary of the literature. A 55-year-old female presented with symptoms due to a large right RCC. Staging investigations were negative for metastasis and she underwent curative resection. She presented 8 years later with cholecystitis, and histological examination of the gallbladder specimen identified metastatic renal cell carcinoma which was not identified on preoperative imaging. RCC metastases to the gallbladder are unusual, but probably more common than recognised. They're frequently not identified preoperatively, and prognosis is similar to isolated metastases to other organs.

Anorectal melanoma: not a haemorrhoid.

AIM: Melanoma of the anorectum is a rare malignancy which is particularly aggressive compared to cutaneous melanoma. Due to its presenting symptoms, location and rarity there is often a delay in diagnosis. The purpose of this paper is to raise awareness of anorectal melanoma in New Zealand by presenting our institution's experience of four cases. METHODS: The presentation, management and outcomes of four cases are described. A review of the literature surrounding anorectal melanoma was also carried out. RESULTS: The four cases (3 male, 1 female, aged 30-87 years) all presented with haemorrhoidal symptoms of anal discomfort and/or outlet rectal bleeding. Three patients had metastatic disease at presentation, and the remaining patient was found to have a concurrent lymphoma which was treated with chemotherapy before he underwent excision of the melanoma. Surgical excision is the mainstay of treatment and recent literature suggests transanal excision of the primary tumour to have equivalent overall survival to abdominoperineal resection. CONCLUSION: Anorectal melanoma is rare tumour with a poor prognosis. Patients are commonly misdiagnosed as having haemorrhoids; therefore a high index of suspicion is needed to enable early diagnosis. Metastatic disease is common at presentation, and the key prognostic indicator. Local control can be obtained with transanal excision, avoiding the morbidity of abdominoperineal resection. Adjuvant therapies available at present provide little survival advantage.

Genetic structure of little brown bats (Myotis lucifugus) corresponds with spread of white-nose syndrome among hibernacula.

Until recently, the little brown bat (Myotis lucifugus) was one of the most common bat species in North America. However, this species currently faces a significant threat from the emerging fungal disease white-nose syndrome (WNS). The aims of this study were to examine the population genetic structure of M. lucifugus hibernating colonies in Pennsylvania (PA) and West Virginia (WV), and to determine whether that population structure may have influenced the pattern of spread of WNS. Samples were obtained from 198 individuals from both uninfected and recently infected colonies located at the crest of the disease front. Both mitochondrial (636bp of cytochrome oxidase I) and nuclear (8 microsatellites) loci were examined. Although no substructure was evident from nuclear DNA, female-mediated gene flow was restricted between hibernacula in western PA and the remaining colonies in eastern and central PA and WV. This mitochondrial genetic structure mirrors topographic variation across the region: 3 hibernating colonies located on the western Appalachian plateau were significantly differentiated from colonies located in the central mountainous and eastern lowland regions, suggesting reduced gene flow between these clusters of colonies. Consistent with the hypothesis that WNS is transmitted primarily through bat-to-bat contact, these same 3 hibernating colonies in westernmost PA remained WNS-free for 1-2 years after the disease had swept through the rest of the state, suggesting that female migration patterns may influence the spread of WNS across the landscape.