Frank D. McDermott

Systematic review of preoperative, intraoperative and postoperative risk factors for colorectal anastomotic leaks

Anastomotic leak (AL) represents a dreaded complication following colorectal surgery, with a prevalence of 1–19 per cent. There remains a lack of consensus regarding factors that may predispose to AL and the relative risks associated with them. The objective was to perform a systematic review of the literature, focusing on the role of preoperative, intraoperative and postoperative factors in the development of colorectal ALs.

Minimally invasive and surgical management strategies tailored to the severity of acute diverticulitis.

The severity of acute diverticulitis ranges from mild, simple inflammation to pericolic abscesses, or perforation with faeculent peritonitis. Treatment of diverticulitis has evolved towards more conservative and minimally invasive strategies. The aim of this review is to highlight recent concepts and advances in management.

The effects of polyamines on human colonic mucosal function

Electrogenic ion transport in human colon is a surrogate marker for colonic mucosal function, and may be manipulated by a variety of hormonal, neural, immune and paracrine mediators. Polyamines are present in vast quantities in the colonic lumen and appear to be integral to cellular function. This study explores some of the mechanisms of polyamine action on colonic tissue through study of their effects on differential secretory pathways, as well as examining their actions on intracellular cAMP and Ca(2+) accumulation. Human colonic mucosa was mounted in Ussing chambers and treated with polyamines (spermine, spermidine and putrescine) with changes in ion transport recorded. In separate experiments colonic crypts were treated with polyamines and intracellular cAMP levels determined by ELISA and intracellular calcium concentrations were quantified by fluorescent imaging. Polyamines at physiological concentrations (1mM) exert no effects on basal mucosal chloride secretion or transepithelial electrical resistance. Polyamines inhibit electrogenic ion secretion as stimulated by forskolin (cAMP-mediated), but not carbachol (Ach-mediated). All the polyamines used in this study inhibited intracellular cAMP accumulation, according to potency (spermine>spermidine>putrescine). Spermine increased intracellular Ca(2+) in a PKC-dependent manner, likely due to its effects on the extracellular calcium-sensing receptor (CaSR). Polyamines act to prevent cAMP-mediated Cl(-) hypersecretion in the colon, acting through CaSR to inhibit PKC-mediated [Ca(2+)]i release from intracellular stores.

Laparoscopic Spigelian Hernia Repair: A Series of 40 Patients.

Spigelian hernias are a rare abdominal wall hernia. The aim of this study was to assess the efficacy and outcomes of patients who underwent a laparoscopic spigelian hernia repair. A retrospective study was performed reviewing all patients who had a laparoscopic spigelian hernia repair. We assessed the success of the procedure including conversion rates, postoperative morbidities, and recurrence rates. Forty patents had a laparoscopic repair. Two thirds (n=25) had an intraperitoneal repair. There was no conversion to open repair. Four patients had postoperative morbidities. At 6-month follow-up all patients were pain free, with 1 recurrence. There is considerable evidence supporting the opinion that laparoscopic repair offers excellent outcomes. This report is the largest series to date, and we advocate that this approach should become the standard of care.

OC-070 Ml:8: a novel surgical irrigant reduces viable bacterial load in sheets of human colon ex vivo

Introduction ML:8 is a proprietary emulsion of fatty acids and triglycerides with efficacy at eliminating biofilms, and has been evaluated as a central line locking solution. These components are potentially less toxic than more traditional chlorhexidine or iodine. With increasing incidence of resistant bacteria and interest in the colonic microbiome; a surgical irrigation ML:8 formulation was developed that may have experimental and clinical applications. The aim was to test efficacy and effect of ML:8 on ex-vivo human colonic tissues compared to current solutions in clinical use. Method Human tissues obtained from healthy margin of freshly resected sigmoid colon. Tissues exposed for 2 min to one of 4 solutions: Control Krebs Henseleit (KH), 0.9% NaCl, 1% povidone iodine (I2), 2% ML:8 n = 4. Mucosal surfaces swabbed for culture using Petrifilms®. Colony forming units (CFUs) counted at 48 h by 2 blinded operators. Mucosal sheets mounted in Ussing chambers with KH (37oC, 95% O2/5% CO2) and voltage clamped. At the end tissues challenged with muscarinic agonist, carbachol as a marker of epithelial function. Permeability coefficient (Papp) was derived using [14C] mannitol. Tissues were fixed in formalin for histology. Results Similar CFUs grew in aerobic and anaerobic conditions in control and NaCl tissues. I2reduced (p < 0.05) and ML:8 virtually abolished viable bacteria (p < 0.05). Short circuit current (SCC; μA/cm2) and Potential difference (PD; mV) not different between treatments. SCC at time 0: –34.2 ± 6.0, –35.4 ± 10.8, –27.0 ± 2.8, –42.3 ± 4.3 for KH, NaCl, I2 and ML-8 respectively (p = 0.11). PD time 0: –5.8 ± 2.4, 2.9 ± 0.5, –3.6 ± 0.4, –3.2 ± 1.1 (p = 0.24). Transepithelial Electrical Resistance (TEER Ω.cm2) higher in control group: 118.5 ± 29.2, 47.7 ± 16.4, 92.0 ± 15.4, 69.8 ± 11.5 but did not reach significance (p = 0.05). Tissues responded to carbachol although attenuated in I2treated tissue (p = < 0.05). Papp higher in all treated tissues but this did not reach significance (p = 0.07). Histopathological assessment revealed no overt damage to tissues and crypt heights uniform. Conclusion ML:8 rapidly and effectively reduced bacterial counts with no adverse effects on a broad range of functional and structural parameters on human colonic mucosa ex vivo . This represents a potentially powerful tool for exploring mechanisms of host-microbiome interactions similar to gnotobiotic animal models. Brief exposure to ML:8 had comparable outcomes to control treated tissues and possibly less impact than iodine. These are early experiments but potential future clinical applications of ML:8 include decolonisation for elective surgery, prior to faecal transplantation for C.difficileor for surgical sepsis e.g. perforated colon. Disclosure of interest F. Mcdermott: None Declared, D. Folan: None Declared, D. Winter: None Declared, M. Folan Conflict with: Company Director of Capstan Healthcare Ltd, A. Baird Conflict with: Company Director of Capstan Healthcare Ltd.

Gnotobiotic Human Colon Ex Vivo

Background A novel emulsion with efficacy as an agent for eliminating biofilms was selected. The aim of this study was to examine efficacy and effect of a formulation of ML:8 against commensal bacteria harvested from ex vivo human colonic tissues. Methods Mucosal sheets, obtained at the time of surgery, were exposed for 2 minutes to one of four solutions: Krebs-Hensleit (KH) solution, saline (NaCl; 0.9%), povidone iodine (1%), or ML:8 (2%); n = 4. Lumenal surfaces were swabbed for culture under aerobic or anaerobic conditions. Following treatment, each sheet was mounted in Ussing chambers and voltage clamped. Tissues were challenged with carbachol. Permeability coefficient (Papp) was determined using mannitol fluxes. At the end of each experiment, tissues were examined histologically. Results Similar colony forming units grew in aerobic and anaerobic conditions in both control and NaCl treated tissues. Iodine reduced and ML:8 virtually abolished viable bacteria. Basal electrophysiological parameters were not different between treatments. Transepithelial electrical resistance values did not differ between groups. All tissues responded to carbachol, although this was attenuated in iodine treated tissue. Papp values were slightly elevated in all treated tissues but this did not reach significance. Histopathological assessment revealed no overt damage to tissues. Conclusion Brief exposure to ML:8 reduced culturable bacterial burden from human intestinal tissues harvested at the time of surgical resection. Such gnotobiotic tissues retain structural and functional integrity. This is a novel approach to reduce bacterial burden.

Torsion of an intraperitoneal undescended seminomatous testicular tumour

A 42-year-old man presented acutely with lower abdominal peritonism and a medical history of a right orchidopexy as a child. Further history from his mother revealed that during the procedure the left testicle could not be found. In view of his unusual history and the nature of the pain a CT scan was performed demonstrating a 10×8 cm solid mass above the bladder. The mass was removed electively and revealed a torted left testicular mass. Histopathology confirmed a torted seminomatous tumour. This case highlights the importance of returning undescended testes to the scrotum or confirming absence to preserve function and ease surveillance of potential future neoplastic transformation. The current management for impalpable undescended/absent testicles involves radiological imaging, inguinal and/or laparoscopic exploration and orchidopexy before 18 months of age.