A cost-utility study of elective haemorrhoidectomies in Canada.

AIM: The aim was to estimate the 10-year cost-utility of haemorrhoidectomy surgery with preference-based measures of health using Canadian health utility measures and costs. METHODS: Patients undergoing elective haemorrhoidectomies by general and colorectal surgeons in British Columbia, Vancouver, between September 2015 and November 2022, completed preoperatively and postoperatively the EuroQol five-dimension five-level health-related quality of life questionnaire (EQ-5D-5L). Quality-adjusted life years (QALYs) attributable to surgery were calculated by discounting preoperative and postoperative health utility values derived from the EQ-5D-5L. Costs were measured from a health system perspective which incorporated costs of hospital stay and specialists' fees. Results are presented in 2021 Canadian dollars. RESULTS: Of 94 (47%) patients who completed both the preoperative and postoperative questionnaires, the mean gain in QALYs 10 years after surgery was 1.0609, assuming a 3.5% annual discounting rate. The average cost of the surgery was $3166. The average cost per QALY was $2985 when benefits of the surgery were assumed to accrue for 10 years. The cost per QALY was higher for women ($3821) compared with men ($2485). Participants over the age of 70 had the highest cost per QALY ($8079/QALY). CONCLUSIONS: Haemorrhoidectomies have been associated with significant gains in health status and are inexpensive relative to the associated gains in quality of life based on patients' perspectives of their improvement in health and well-being.

Effect of Kono-S anastomosis on reducing postoperative recurrence rates in Crohn's disease: a systematic review and meta-analysis.

BACKGROUND: Kono-S anastomosis has gained increasing interest although evaluation of its impact on reducing Crohn's recurrence shows conflicting results. This study aimed to evaluate the short- and long-term outcomes for patients with Crohn's disease requiring surgery with Kono-S compared to conventional anastomosis. METHODS: A systematic review and meta-analysis included patients with Crohn's disease treated with bowel resection and Kono-S anastomosis reconstruction versus a comparator arm of conventional anastomosis technique. Recurrence outcomes examined were endoscopic recurrence rates, mean postoperative Rutgeerts score, surgical recurrence, clinical recurrence, and postoperative biologics use. Short-term postoperative outcomes include anastomotic leaks, surgical site infection, postoperative ileus, and mean operative time. RESULTS: A total of 873 studies were identified with 15 remaining after abstract review encompassing 1501 patients, 765 with Kono-S and 736 with conventional anastomosis. Recurrence was significantly lower in the Kono-S arm, with endoscopic recurrence rates of 41% vs 48% (RR 0.86, 95% CI 0.73-1.00, p = 0.05) and surgical recurrence rates of 2.7% vs 21.0% (RR 0.13, 95% CI 0.06-0.30, p < 0.001). There was a significantly lower anastomotic leak rate in the Kono-S arm when compared to conventional anastomosis, 1.7% vs 4.9% (RR 0.37, 95% CI 0.19-0.74, p = 0.005). Mean operative time was similar between both groups. CONCLUSIONS: Kono-S is a safe and feasible anastomotic technique with lower rates of endoscopic and surgical postoperative recurrence. While we await further trials to substantiate this benefit, Kono-S anastomosis should be considered as an important tool in the armamentarium of a surgeon in anastomotic construction to reduce recurrence.

Surgical site infection in elective colonic and rectal resections: effect of oral antibiotics and mechanical bowel preparation compared with mechanical bowel preparation only.

AIM: Surgical site infections are disproportionately common after colorectal surgery and may be largely preventable. The objective of this retrospective cohort study was to determine the effect of oral antibiotics and mechanical bowel preparation on surgical site infections. METHOD: A retrospective study of a consecutive series of elective colonic and rectal resections following an Enhanced Recovery After Surgery pathway, which also included mechanical bowel preparation, from 1 September 2014 to 30 September 2017. The addition of oral antibiotics (neomycin and metronidazole) to the mechanical bowel preparation procedure was assessed. Development of surgical site infections within 30 days was the main outcome measured. The secondary outcome was assessment of possible surgical site infection predictors. RESULTS: Seven-hundred thirty-two patients were included: 313 (43%) preintervention (mechanical bowel preparation only); and 419 (57%) postintervention (mechanical bowel preparation plus oral antibiotics). Surgical site infection rates preintervention and. postintervention were: overall, 20.8% vs 10.5%, P < 0.001; superficial, 10.9% vs 4.3%, P < 0.001; and organ space, 9.9% vs 6.2%, P = 0.03. Subgroup analysis of colonic resections revealed a significant reduction in overall (17.1% vs 6.8%), superficial (10.7% vs 4.3%) and organ space (6.4% vs. 2.6%) infections. Rectal resections had significant reduction in overall (26.2% vs 15.3%) and superficial (11.1% vs 4.4%) infection rates but not in organ space infections (15.1% vs 10.9%). Multivariate regression analysis revealed open vs minimally invasive surgery (P < 0.001) and omission of oral antibiotics (P = 0.004) as independent predictors of surgical site infections. CONCLUSION: Administration of oral antibiotics resulted in significant reduction of superficial and organ space infections after colonic resection; after rectal resection, significant reduction only of superficial infections was found.

Health and quality of life among a cohort of patients having lateral internal sphincterotomy for anal fissures.

AIM: The aim of this study is to report changes in health-related quality of life attributable to lateral internal sphincterotomy for treatment of anal fissure. There is very little evidence on whether the overall health-related quality of life of patients is detrimentally affected by the condition, or which aspects of self-perceived health status improve after lateral internal sphincterotomy. This study will articulate which aspects of health tend to improve and guide postoperative expectations appropriately. Knowledge gained from this study may also identify gaps in an individual patient's episode of care. METHOD: Patients were prospectively identified when they consented to surgical treatment of their anal fissure and were contacted by phone to participate. Participants completed a number of patient-reported outcomes preoperatively and 6 months postoperatively. Faecal incontinence-related quality of life, pain and depression were measured at both time points. The severity of faecal incontinence was measured at both times. RESULTS: Participants reported high levels of pain preoperatively. Postoperatively, improvement in pain exceeded the threshold of clinical relevance (P < 0.01). Thirty-five per cent of participants reported significant effects of faecal incontinence preoperatively, while 26% did so postoperatively. Participants with multiple comorbidities were more likely to report faecal incontinence postoperatively than preoperatively. CONCLUSION: This study reports that lateral internal sphincterotomy improved pain symptoms without adverse effects on continence. Not all domains of health-related quality of life were similarly positively affected by anal fissure repair.

A multi-centre randomized controlled trial of open vs closed management of the rectal defect after transanal endoscopic microsurgery.

AIM: Transanal endoscopic microsurgery (TEM) is a technically challenging strategy that allows expanded indications for local excision of rectal lesions. Transluminal suturing is difficult, so open management of the resultant defect is appealing. Expert opinion suggests there is more pain when the defect is left open. The aim of this study was to determine if closure of the defect created during full thickness excision of rectal lesions with TEM leads to less postoperative pain compared to leaving the defect open. METHOD: At the time of surgery, patients undergoing a full thickness TEM were randomized to sutured (TEM-S) or open (TEM-O) management of the rectal defect. At five Canadian academic colorectal surgery centres, experienced TEM surgeons enrolled patients ≥ 18 years treated by full thickness TEM. The primary outcome was postoperative pain measured by the visual analogue scale. Secondary outcomes included postoperative pain medication use and 30-day postoperative complications, including bleeding, infection and hospital readmission. RESULTS: Between March 2012 and October 2013, 50 patients were enrolled and randomized to sutured (TEM-S, n = 28) or open (TEM-O, n = 22) management of the rectal defect. There was no difference between the two study groups in postoperative pain on postoperative day 1 (2.8 vs 2.6, P = 0.76), day 3 (2.8 vs 2.1, P = 0.23) and day 7 (2.8 vs 1.7, P = 0.10). CONCLUSION: In this multicentre randomized controlled trial, there was no difference in postoperative pain between sutured or open defect management in patients having a full thickness excision with TEM.

Transanal endoscopic microsurgery as day surgery - a single-centre experience with 500 patients.

AIM: Transanal endoscopic microsurgery (TEM) is the current treatment of choice for rectal adenomas and early rectal cancer. Postoperative admission to hospital is common but possibly unnecessary. Our objective was to analyse predictors and outcomes of TEM patients having same day discharge (TEM-D) compared with those who were admitted to hospital (TEM-A). METHOD: At St Paul's Hospital (SPH), demographic, surgical, pathological and follow-up data have been collected prospectively since TEM was started in 2007. Trends in admission and readmission rates were analysed using the Cochran-Armitage trend test, and predictors of admission were analysed using univariate and multivariate logistic regressions. RESULTS: Between 2007 and 2016, 500 patients were treated by TEM at SPH. The overall admission rate was 29% (145/500), but this decreased to 19% in the last 3 years of the study (P < 0.001). The readmission rate was 5.2% (n = 26/500) and did not change significantly over the study period (P = 0.30). Reasons for admission included the following: surgeon discretion/monitoring (35%), urinary retention (26%), haemorrhage (10%), breach of peritoneal cavity (7%), infection (7%) and other (15%). The most common reasons for readmission were haemorrhage (54%, n = 14), pain (19%, n = 5) and infection (12%, n = 3). Factors associated with admission were as follows: tumour height (OR 1.09, 1.02-1.17), prolonged operative time (OR 1.25, 1.14-1.37), unsutured surgical defect (OR 1.99, 1.22-3.25) and surgeon experience (OR 4.62, 2.75-7.77). CONCLUSION: Outpatient TEM is safe and carries a low risk of readmission. In centres with an outpatient TEM strategy, predictors of hospital admission include proximal tumours, prolonged surgical time and open management of the surgical defect.

Salvage TME following TEM: a possible indication for TaTME.

BACKGROUND: Salvage surgery after transanal endoscopic microsurgery (TEM) has shown mixed results. Transanal total mesorectal excision (TaTME) might be advantageous in this population. The aim of this study was to assess the short-term oncologic and operative outcomes of salvage surgery after TEM, comparing TaTME to conventional salavge TME (sTME). METHODS: Consecutive patients treated with salvage surgery after TEM were identified. Patients who underwent TaTME were compared to those who had conventional sTME. The primary outcome was the ability to perform an appropriate oncologic procedure defined by a composite outcome (negative distal margins, negative radial margins and complete or near complete mesorectum specimen). RESULTS: During the study period, 41 patients had salvage surgery after TEM. Of those, 11 patients had TaTME while 30 patients had sTME. All patients in the TaTME group met the composite outcome of appropriate oncologic procedure compared to 76.7% for the conventional sTME group (p = 0.19). TaTME was associated with significantly higher rates of sphincter preservation (100 vs. 50%, p = 0.01), higher rates of laparoscopic surgery (100 vs. 23.3%, p < 0.001) and lower rates of conversion to open surgery (9.1 vs. 57%, p < 0.001). No difference was found in postoperative morbidity (36.3 vs. 36.7%, p = 0.77). CONCLUSIONS: The present study demonstrates that for patients requiring salvage surgery after TEM, TaTME is associated with significantly higher rates of sphincter-sparing surgery when compared to conventional transabdominal TME while producing adequate short-term oncologic outcomes. Salvage surgery after TEM might be a clear indication for TaTME rather than conventional surgery.

Randomized double-blind trial comparing the cosmetic outcome of cutting diathermy versus scalpel for skin incisions.

BACKGROUND: Controversy exists about whether cutting diathermy for skin incisions leads to a cosmetically inferior scar. Cosmetic outcomes were compared between skin incisions created with cutting diathermy versus scalpel. Wound infection rates and postoperative incisional pain were also compared. METHODS: This was a randomized double-blind trial comparing cutting diathermy and scalpel in patients undergoing bowel resection. Scar cosmesis was assessed at 6 months after surgery by a plastic surgeon and a research associate using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). Patients also used POSAS to self-evaluate their scars. Wound infections within 30 days were recorded, and incision pain scores were measured on the first 5 days after operation. RESULTS: A total of 66 patients were randomized to cutting diathermy (31) or scalpel (35). At 6 months, there was no significant difference between the diathermy and scalpel groups in mean(s.d.) VSS scores (4·9(2·6) versus 5·0(1·9); P = 0·837), mean POSAS total scores (19·2(8·0) versus 20·0(7·4); P = 0·684) or subjective POSAS total scores (20·2(12·1) versus 21·3(10·4); P = 0·725). Neither were there significant differences in wound infection rates between the groups (5 of 30 versus 5 of 32; P = 1·000). Pain scores on day 1 after operation were significantly lower in the diathermy group (mean 1·68 versus 3·13; P = 0·018), but were not significantly different on days 2-5. CONCLUSION: Cutting diathermy is a cosmetically acceptable technique for abdominal skin incisions. There is no increased risk of wound infection, and diathermy may convey benefit in terms of early postoperative wound pain. REGISTRATION NUMBER: NCT01496404 ( http://www.clinicaltrials.gov).

Transanal versus conventional total mesorectal excision for rectal cancer using the IDEAL framework for implementation.

BACKGROUND: Transanal total mesorectal excision (TaTME) is an innovative technique for distal rectal cancer dissection. It has been shown to have similar short-term outcomes to conventional open and laparoscopic total mesorectal excision (cTME), but recent studies have raised concern about increased morbidity and local recurrence rates. The aim of this study was to assess outcomes after TaTME versus cTME for rectal cancer. METHODS: TaTME was implemented in 2014 using IDEAL principles in a single institution. The institution maintains databases for all patients undergoing rectal cancer surgery. This retrospective review compared data collected from all patients who had TaTME with those from a propensity-matched cohort of patients who underwent cTME. The primary outcome was a composite pathological measure combining margin status and quality of total mesorectal excision (TME). Short-term clinical and survival outcomes were also measured. RESULTS: Propensity matching created 109 matched pairs for analysis. Nine patients (8.3 per cent) undergoing TaTME had positive margins and/or incomplete TME, compared with 11 (10.5 per cent) undergoing cTME (P = 0.65). There were no significant differences in morbidity between the TaTME and cTME groups, including number of anastomotic leaks (13.8 versus 18.3 per cent; P = 0.37). The estimated 3-year local recurrence-free survival rate was 96.3 per cent in both groups (P = 0.39). Estimated 3-year overall (93.6 per cent for TaTME versus 94.5 per cent for cTME; P = 0.09) and disease-free (88.1 versus 76.1 per cent; P = 0.90) survival rates were similar. CONCLUSION: TaTME provided similar outcomes to cTME for rectal cancer with the application of IDEAL principles.

Transanal Endoscopic Microsurgery (TEM) for rectal GI stromal tumor.

BACKGROUND: Transanal endoscopic microsurgery (TEM) is effective in treating adenomas and select early rectal cancers. Our objective is to evaluate TEM in treating early rectal GISTs. METHODS: Patients were identified in a prospective database with pathology confirmed rectal GIST prior to TEM over 10 years. Demographic, pathologic, operative and follow-up data was analysed and presented with descriptive statistics. RESULTS: 7 cases of rectal GIST were treated with TEM with a follow-up time of 31 months (0-71). Median tumor distance from the anal verge was 4 cm (2.5-6) and median tumor size was 3 cm (2-5.7). Negative margins were achieved in 4/7 patients. Those with positive margins were treated with repeat TEM or imatinib. 1 patient had local recurrence successfully treated by TEM. CONCLUSIONS: Overall, TEM is safe for locally excising GISTs. As rectal GISTs are rare, a multicenter registry may better elucidate outcomes with this treatment.

A universal method for the mutational analysis of K-ras and p53 gene in non-small-cell lung cancer using formalin-fixed paraffin-embedded tissue.

The p53 tumor suppressor gene has been found to be altered in almost all human solid tumors, whereas K-ras gene mutations have been observed in a limited number of human cancers (adenocarcinoma of colon, pancreas, and lung). Studies of mutational inactivation for both genes in the same patient's sample on non-small-cell lung cancer have been limited. In an effort to perform such an analysis, we developed and compared methods (for the mutational detection of p53 and K-ras gene) that represent a modified and universal protocol, in terms of DNA extraction, polymerase chain reaction (PCR) amplification, and nonradioisotopic PCR-single-strand conformation polymorphism (PCR-SSCP) analysis, which is readily applicable to either formalin-fixed, paraffin-embedded tissues or frozen tumor specimens. We applied this method to the evaluation of p53 (exons 5-8) and K-ras (codon 12 and 13) gene mutations in 55 cases of non-small-cell lung cancer. The mutational status in the p53 gene was evaluated by radioisotopic PCR-SSCP and compared with PCR-SSCP utilizing our standardized nonradioisotopic detection system using a single 6-microns tissue section. The mutational patterns observed by PCR-SSCP were subsequently confirmed by PCR-DNA sequencing. The mutational status in the K-ras gene was similarly evaluated by PCR-SSCP, and the specific mutation was confirmed by Southern slot-blot hybridization using 32P-labeled sequence-specific oligonucleotide probes for codons 12 and 13. Mutational changes in K-ras (codon 12) were found in 10 of 55 (18%) of non-small-cell lung cancers. Whereas adenocarcinoma showed K-ras mutation in 33% of the cases at codon 12, only one mutation was found at codon 13. As expected, squamous cell carcinoma samples (25 cases) did not show K-ras mutations. Mutations at exons 5-8 of the p53 gene were documented in 19 of 55 (34.5%) cases. Ten of the 19 mutations were single nucleotide point mutations, leading to amino acid substitution. Six showed insertional mutation, and three showed deletion mutations. Only three samples showed mutations of both K-ras and p53 genes. We conclude that although K-ras and p53 gene mutations are frequent in non-small-cell lung cancer, mutations of both genes in the same patient's samples are not common. We also conclude that this universal nonradioisotopic method is superior to other similar methods and is readily applicable to the rapid screening of large numbers of formalin-fixed, paraffin-embedded or frozen samples for the mutational analysis of multiple genes.

Coated silica tips for use in high-pressure, high-temperature, scanning tunneling microscopy.

A novel application of coated silica tips for use in high-pressure, high-temperature, scanning tunneling microscopy is introduced. Thermal drift is reduced in the Z-direction due to the low thermal expansion of silica. Virtually, any conducting material that can be evaporated or sputtered can be used as a tip material. Experimental results are shown for tips sputter coated with platinum, along with images obtained.

Role of media constituents and proline in callus growth, somatic embryogenesis and regeneration of Oryza sativa cv Indica.

Conditions were optimised for efficient callus induction from seeds of four local indica rice cultivars, GR-3, GR-102, Jaya and Te-Tep. Addition of 2,4-D to MS medium at 2.5 mg/l resulted in 100% callus induction. N6 medium was superior to MS medium for callus growth, formation of embryogenic callus as well as regeneration. Cultivar Te-Tep showed highest callus growth while GR-102 the least. Addition of casein hydrolysate enhanced growth of callus but did not yield more embryogenic calli. Supplementation of MS or N6 media with proline, not only increased callus growth but also showed an increase in embryogenic callus formation. GR-102 callus was most embryogenic followed by Te-Tep, GR-3 and Jaya. Histological observation of embryogenic calli revealed the presence of pro-embryo like structures. It was also observed that calli induced on N6 medium supplemented with proline could maintain regeneration potential for a longer period as compared to other media. Cytokinins like BAP or kinetin alone could not initiate shoot formation. Regeneration frequency, and the number of shoots formed per callus increased significantly. Cultivar Te-Tep gave the best response for regeneration followed by Jaya, GR-3 and GR-102.

Evolution of oxygen evolving reaction center-II of thylakoids.

A model for evolution of oxygen evolving reaction center II of higher plant initiating from a chlorophyll--quinone complex is proposed. The reaction center gradually incorporates pheophytin, Fe and Mn to finally achieve oxidation of water to oxygen. The structural and functional pattern during evolution is proposed to descend from higher order of symmetry to lower one.

Prediction of the conformation of D1/D2 heterodimer of photosynthetic reaction centre II using a modified Chou-Fasman method.

Chou-Fasman method was modified to account for amphipathic nature of Gly and hydrophobic environment. The modified method shows improvement in prediction accuracy from 35 to 70% and can be applied to predict the conformation of D1, D2 polypeptides of reaction centre II of thylakoid, which are analogous to L and M respectively. Possible sites for Mn binding to D1/D2 heterodimer are postulated.

Comparative modelling of tetramanganese cluster of Chaetosphaeridium globosum.

The DI protein of photosystem II (PS II) complex of a microalga Chaetosphaeridium globosum has been theoretically modelled from its sequence using comparative modeling with known backbone structure of DI protein from bacterium Thermosynechococcus vulcanus as template. The model is built with missing loops and all side chains, which are not resolved in the structure of the template. The structure of the tetramanganese cluster (TMC) and the ligand forming side chains have been subjected to modeling studies in order to gather more information useful to understanding of the water splitting reactions. Earlier models of TMC have been scrutinized and an insight into the manganese coordination sphere has been provided.

A model for the organization of chlorophyll-protein complex of photosystem II and analysis of its photochemical efficiency and excitation migration.

A model is proposed for the organization of chlorophyll-protein complex in photosystem II (PS II) of higher plants. The rates of exciton migration and exciton trapping have been computed using stochastic method to find out the photochemical efficiency of the dimeric PS II. Three dimeric PS II units are assumed to form a group, as transfer of the exciton to the light harvesting bed of the nearest neighbour on either side may only be effective. A relationship has been deduced between the fractions of the reaction centre traps closed and the number of jumps (J) required by the exciton for trapping. The photochemical efficiency and fluorescence quantum yield are computed using J as the parameter in an empirical equation.

Prediction of structure of antenna proteins of photosystem II.

Membrane spanning regions of 43 kDa and 47 kDa antenna proteins of photosystem II of thylakoid membranes are theoretically predicted. Prediction of topology of chlorophyll-a and beta-carotene molecules in the proteins and interaction of the proteins with 33 kDa extrinsic protein on the lumenal side of thylakoid membrane is based on the findings reported earlier. Each antenna protein is predicted to have six transmembrane alpha-helices with twelve chlorophyll-a and five beta-carotene molecules binding to it. Both N- and C- terminal ends are proposed to be on the stromal side of thylakoid membrane. The proposed structural model conforms to the reported experimental results from the literature.

Modelling a binuclear metal binding site in the photosynthetic reaction centre II.

Based on the experimental data and homologous sites in Protein Data Bank (PDB) a model for metal binding sites in D1/D2 heterodimer has been proposed. On searching for tetranuclear and binuclear Mn binding sites in the PDB, a suitable sequence homology in thermolysin and D1 could be observed. From the homology and site-directed mutagenesis data, a model for binuclear Mn-Ca or Mn-Mn has been built and it is extended to a tetranuclear Mn centre.