Recurrence after transanal endoscopic microsurgery for benign and malignant rectal tumours: experience of a single New Zealand centre

BACKGROUND

Transanal endoscopic microsurgery (TEM) is an established technique for the resection of rectal adenomas and selected malignant tumours. It avoids the morbidity of radical resection for tumours not amenable to endoscopic resection. An important marker of quality is the local recurrence rate. The primary objective was to determine local recurrence rates for benign and malignant rectal tumours.

METHODS

We identified index TEM excisions of rectal adenomas and adenocarcinomas in patients age 18 and over at Dunedin Hospital, New Zealand, between 2000 and 2020, from a prospective database. Surveillance data were collected via chart review. The primary outcome was recurrence rate for adenomas and adenocarcinomas. Secondary outcomes included time to recurrence, association of recurrence with recognized risk factors, and adverse event rates.

RESULTS

We identified 100 patients for analysis. Of 75 benign cases, 11 (14.7%) developed local recurrence, with 63.6% identified within 1 year. Of the 25 malignant cases (19 T1, 5 T2, 1 T3), 9 (36%) developed recurrence, with 77.8% identified within 2 years. Adverse events occurred in 26% of patients, with no reoperations or deaths.

CONCLUSION

Our adenoma recurrence rate was at the higher end of the reported range of 2.4-16%. Minor complications were common, but not major morbidity. The propensity for rectal tumours to recur commonly and early reinforces the importance of regular standardized endoscopic surveillance.

Role for colorectal teams to support non-colorectal teams to improve clinical outcomes and adherence to ERAS guidelines for segmental colectomy: a cohort study

Background

To identify whether compliance with Enhanced Recovery After Surgery (ERAS) Society recommendations is associated with length of stay (LOS) in a New Zealand hospital for patients undergoing segmental colectomy in mixed acute and elective general surgery wards.

Methods

Consecutive elective colorectal surgeries (n = 770) between October 2012 and February 2019 were audited. Patients with non-segmental colectomies, multi-organ surgeries, LOS > 14 days, and those who died were excluded. Logistic regression was used to determine the relationship between patient demographics, compliance with ERAS guidelines, and suboptimal LOS (> 4 days).

Results

Analysis included 376 patients. Age, surgery prior to 2014, surgical approach, non-colorectal surgical team, operation type, and complications were significantly associated with suboptimal LOS. Non-compliance with ERAS recommendations for laparoscopy [OR 8.9, 95% CI (4.52, 19.67)], removal of indwelling catheters (IDC) [OR 3.14, 95% CI (1.85, 5.51)], use of abdominal drains [OR 4.27, 95% CI (0.99, 18.35)], and removal of PCA [OR 8.71, 95% CI (1.78, 157.27)], were associated with suboptimal LOS (univariable analysis). Multivariable analysis showed that age, surgical team, late removal of IDC, and open approach were independent predictors of suboptimal LOS.

Conclusions

Non-compliance with ERAS guidelines for laparoscopic approach and early removal of IDC was higher among procedures performed by non-colorectal surgery teams, and was also associated with adverse postoperative events and suboptimal LOS. This study demonstrates the importance of the surgical team’s expertise in affecting surgical outcomes, and did not find significant independent associations between most individual ERAS guidelines and suboptimal LOS once adjusting for other factors.

Loop ileostomy closure: a retrospective comparison of three techniques

BACKGROUND

Loop ileostomy (LI) formation is a common practice for patients undergoing low anterior resection or restorative ileo-anal pouch surgery. Ileostomy closure can be performed using a stapled or hand-sewn technique, with or without resection. If hand-sewn, the closure can be one or two layers. Randomized controlled trials have not demonstrated one technique to be superior, and meta-analyses are limited by the heterogeneity of published studies. Our primary aim is to compare stapled ileostomy closure with single- and two-layer hand-sewn closures.

METHODS

This retrospective, single-centre cohort study included patients undergoing LI closure between January 1999 and April 2016. Patient demographics, anastomotic technique, operative time and patient outcomes were collected.

RESULTS

Our analysis included 244 patients (median age 67 years, 43.4% female). There were no significant differences in mean operative times (71.5, 73.1 and 88.5 min, for stapled, single- and two-layer hand-sewn closures, respectively, adjusted overall P = 0.262), or morbidity (21.5% versus 20.4% versus 17.6%, adjusted overall P = 0.934) between stapled or hand-sewn anastomoses, and no mortality. Once adjusting for age, sex, American College of Anaesthesiology grade, and consultant surgeon, the length of stay was different (overall P = 0.034), being similar between stapled and single-layer closures (4.2 versus 5.5 days, P = 0.105), but significantly different between stapled and two-layer closures (4.2 versus 8.3 days, P = 0.026).

CONCLUSION

Stapled and single-layered hand-sewn closures are similar in length of procedure, length of stay and complication rates. A two-layer, hand-sewn technique is associated with a significant increase in stay compared to a stapled ileostomy closure.

Aggravation of Established Colitis in Specific Pathogen-free IL-10 Knockout Mice by Restraint Stress Is Not Mediated by Increased Colonic Permeability

BACKGROUND

Pathogenic mechanisms responsible for the undulating symptom pattern, or indeed causative agents for the development, of inflammatory bowel diseases [IBD] are largely unknown. Many physicians and most patients are convinced that stress affects the course of IBD. As with most factors that contribute to IBD, it is unclear whether stress merely exacerbates established disease or indeed contributes to the development of disease. We designed this study to investigate whether stress induces or aggravates colitis in interkeukin-10 knockout [IL-10 ko] mice and to determine the role of intestinal permeability in this model of stress-related colitis.

METHODS

The study was divided into two experiments depending on the age of the animals. Stress was induced by placing 5-week old disease-free mice or 8-week-old mice (IL-10ko and wild type [wt]) with mild colitis in movement restrainers for 2h twice daily for 7 days. The development of colitis was assessed clinically [weight and faecal pellet production], histologically [haematoxylin and eosin staining], and biochemically [colonic IL-2, IL-4, IL-6, IL-12p40, TNFα, and IFNγ]. Permeability was measured in Ussing chambers.

RESULTS

Faecal pellet production increased significantly in all stressed animals compared with control animals, indicating successful application of stress. Stressed 8-week old mice lost weight [p < 0.001] and stressed IL-10(-/-) mice showed a significantly increased histological score compared with non-stressed or wt mice [p < 0.001]. There was no appreciable difference in cytokine production. Stress did not alter intestinal permeability.

CONCLUSIONS

Restraint stress aggravates experimental colitis in 8-week old IL-10ko mice but cannot induce colitis in disease-free younger mice. This is not mediated by an increased intestinal permeability.

Decision-making bias in assessment: the effect of aggregating objective information and anecdote

INTRODUCTION

Assessment decisions increasingly rely on synthesis of information from a variety of sources. It is known that aggregation of information to make decisions is open to a number of biases. The aim of this research was to investigate bias, accuracy and confidence of assessment decision making.

METHODS

The participants were consultation skills assessors. A model for incremental information was developed with participants being shown results from purposefully selected, but authentic, data from the University's final summative 10-station Objective Structured Clinical Examination (OSCE). After each piece of information, participants gave a pass-fail decision and their confidence in that choice. Following the information from 10 OSCE stations the participants were given a discordant fictional anecdote and again participants gave a pass-fail decision and their confidence.

RESULTS

When there is overwhelming evidence to support a pass or fail, participants were not as confident as the data would support. Participants were less confident to make a fail decision than a pass. Despite considerable evidence from multiple results some participants altered decisions based on isolated contradictory information from an anecdote.

DISCUSSION

These findings are significant in understanding decision-making. Given equivalent levels of evidence, decision makers are less confident to fail than pass and less robust information can undermine more robust information.

Determining measures of insight and foresight from responses to multiple choice questions

BACKGROUND

Clinical decisions require insight and foresight. When these are lacking, overconfidence and error can occur.

AIMS

Multiple choice questions (MCQ) responses were used to estimate insight, as determined by confidence in responses, and foresight, as determined by the safety of incorrect responses.

METHODS

An MCQ response system was developed which reflected confidence in, and safeness of, responses. An optional examination incorporating this system was offered to medical students at one university.

RESULTS

A total of 372 students completed the study. There was evidence of insight. The proportion of responses that were correct rose from 32% for low confidence to 77% for high confidence. The proportion that was incorrect and not unsafe fell from 34% for low confidence to 7% for high confidence. There was less evidence of foresight. Of the responses that were incorrect, the proportion that was unsafe increased from 52% for low confidence to 68% for high confidence. Measures of insight and foresight increased with experience. Students with poorer knowledge chose more unsafe responses, but with lower confidence. Five students gave multiple highly unsafe responses held with high confidence.

CONCLUSIONS

Students had insight but less foresight. Experience and knowledge altered measures of both. This response system identified students who appeared to lack both.

Smoking is a major risk factor for anastomotic leak in patients undergoing low anterior resection

AIM

To examine modifiable risk factors for anastomotic leak in patients undergoing low anterior resection.

METHOD

In total 233 patients undergoing low anterior resection for benign and malignant disease over a 10-year period at a single surgical unit were identified from a prospective database. The relationships between anastomotic leak and 17 variables were examined, including patient demographics, operative technique, tumour pathology, preoperative physiological function and smoking status.

RESULTS

The majority (91%) of operations were carried out for rectal cancers, and 24 procedures (10%) were performed with laparoscopic assistance. The overall anastomotic leak rate was 14% (33/233). Patients with anastomotic leak had higher 30-day mortality (6%vs 1%, P<0.05) and stayed significantly longer in hospital (median 23 vs 10 days, P<0.001). On multivariate analysis, current smokers (OR 3.68, 95% CI 1.38-9.82, P=0.009) and patients with evidence of metastatic malignant disease (OR 3.43, 95% CI 1.29-9.13, P=.013) were at increased risk of anastomotic leak.

CONCLUSION

Smoking and the presence of metastatic disease are major risk factors for the development of anastomotic leak following low anterior resection.

Comprehensive analysis of the bacterial content of stool from patients with chronic pouchitis, normal pouches, or familial adenomatous polyposis pouches

BACKGROUND

Chronic pouchitis is an important long-term complication following ileal pouch-anal anastomosis for ulcerative colitis. Antibiotic administration reduces symptoms of pouchitis, indicating that bacteria have a role in pathogenesis. The aim of the research was to investigate the bacterial content of pouches using nucleic acid-based methods.

METHODS

Stool microbiota of 17 patients with normal pouches (NP), 17 patients with pouchitis (CP) utilizing samples collected from each patient when antibiotic-treated (CP-on, asymptomatic) and when untreated (CP-off, symptomatic), and 14 familial adenomatous polyposis (FAP) patients were analyzed by high-throughput sequencing, fluorescence in situ hybridization technologies, and quantitative polymerase chain reaction (qPCR).

RESULTS

Fluorescence in situ hybridization analysis revealed an expanded phylogenetic gap in NP and CP-off patients relative to FAP. Antibiotic treatment reduced the gap in CP stool. The phylogenetic gap of CP-off patients was due to members of the bacterial families Caulobacteriaceae, Sphingomonadaceae, Comamonadaceae, Peptostreptococcaceae, and Clostridiaceae. There was a greater diversity of phylotypes of Clostridiaceae in CP-off subjects. The phylogenetic gap of NP stool was enriched by Ruminococcaceae and Bifidobacteriaceae. CP stool microbiota had reduced diversity relative to NP and FAP stool due largely to a reduction in Lachnospiraceae/Insertae Sedis XIV/clostridial cluster IV groups.

CONCLUSIONS

Bacterial groups within the expanded phylogenetic gap of pouch patients may have roles in the pathogenesis of pouchitis. Further research concerning the physiology of cultured members of these groups will be necessary to explain their specific roles. Members of the Lachnospiraceae, Incertae Sedis XIV, and clostridial cluster IV could be useful biomarkers of pouch health.

Laparoscopic cholecystectomy through the umbilicus--minimal access surgery gets more minimal

We present the first three reported cases of single incision (through the umbilicus) laparoscopic cholecystectomy in New Zealand. The mean operating time was 108 minutes and all patients were discharged 24 hours after the procedure; they were all satisfied with their procedure and were keen to recommend it. We also provide a review of the international literature on this relatively new technique in New Zealand.

Six years of experience with sacral nerve stimulation for fecal incontinence

PURPOSE

Sacral nerve stimulation is one of many new surgical modalities for fecal incontinence. Short-term results from sacral nerve stimulation have been more encouraging than those from other modalities. The aim of this study was to report the outcome of percutaneous nerve evaluation tests and sacral nerve stimulation for the treatment of fecal incontinence from a single center covering a period of 6 years since the procedure was introduced.

METHODS

All of the candidates for a percutaneous nerve evaluation test and sacral nerve stimulation seen at our anal physiology unit between March 2001 and March 2007 were included in the study.

RESULTS

A total of 177 patients with fecal incontinence (160 females), median age 59.5 (range, 27-88) years, underwent a percutaneous nerve evaluation test. Of these patients, 142 (80%) had a positive test, including 21 of 25 (84%) patients who required a repeat percutaneous nerve evaluation test. Because of a functional failure, 16 patients underwent a revision of the permanent electrode, 7 of whom (44%) were satisfied with the functional result after the revision. Of 126 patients, 15 (12%) have undergone an explantation, with an infection rate of only 1.6%. Overall, after a median follow-up of 24 (range, 3-72) months, the median Wexner incontinence score decreased from 16 (range, 6-20) to 10 (range, 0-20) (P < .0001). In the 10 patients who underwent at least 6 years of treatment, the effect was sustained, as the median Wexner incontinence score decreased from 20 (range, 12-20) to 7 (range, 2-11) (P < .0001).

CONCLUSION

Sacral nerve stimulation is a simple, safe, and minimally invasive technique with low morbidity and excellent results, which appear to be maintained for the first 6 years after the procedure. For patients who underwent the treatment, median Wexner incontinence score decreased significantly after a median follow-up of 24 (range, 3-72) months. Twelve percent were explanted. The infection rate was 1.6%.

Teaching and learning in the hospital ward

AIM

To explore ways in which student learning during formal ward rounds can be enhanced.

METHOD

Qualitative study of University of Otago medical students (Dunedin, New Zealand) involving observation of surgical teams during formal ward rounds, and indepth interviews with students and consultant surgeons.

RESULTS

Teaching and learning opportunities on ward rounds were often missed by both clinical teachers and students as service provision and patient care took precedence. As a result, students often felt excluded and frequently expressed ambivalence about the educational value of formal whole team ward rounds. Students were more likely to consider themselves part of the team when they felt useful and were included in team discussions about patient care. They reported that they learned more effectively on smaller, more educationally focussed ward rounds that incorporated bedside tutorials and opportunities to practice examination skills.

CONCLUSION

Students and clinical teachers know that students need to make the most of learning opportunities by being proactive, spending time on the ward, being useful, asking questions. Clinical staff can facilitate student learning by consciously including students in the business of patient care. This means inviting students to ask questions and examine wounds, physically guiding hands on examinations, encouraging students to pay attention to discussions among the clinical team, and explaining what is being discussed.

NOTES: new dimension of minimally invasive surgery

Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery. NOTES eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. Since the first NOTES was reported by Kalloo et al. in 2004, significant achievements in the laboratory have occurred. Clinical use in humans has been limited, but several cases and one small clinical trial were published recently. As a further technical revolution in minimally invasive surgery, NOTES has the promising potential to be safer, less invasive, provide better cosmesis and possibly be more cost-effective. The purpose of the present article was to review the development and current status of NOTES and highlight important advances associated with this innovative approach.

Reduced expression of a gene proliferation signature is associated with enhanced malignancy in colon cancer

The association between cell proliferation and the malignant potential of colon cancer is not well understood. Here, we evaluated this association using a colon-specific gene proliferation signature (GPS). The GPS was derived by combining gene expression data obtained from the analysis of a cancer cell line model and a published colon crypt profile. The GPS was overexpressed in both actively cycling cells in vitro and the proliferate compartment of colon crypts. K-means clustering was used to independantly stratify two cohorts of colon tumours into two groups with high and low GPS expression. Notably, we observed a significant association between reduced GPS expression and an increased likelihood of recurrence (P<0.05), leading to shorter disease-free survival in both cohorts. This finding was not a result of methodological bias as we verified the well-established association between breast cancer malignancy and increased proliferation, by applying our GPS to public breast cancer data. In this study, we show that reduced proliferation is a biological feature characterizing the majority of aggressive colon cancers. This contrasts with many other carcinomas such as breast cancer. Investigating the reasons underlying this unusual observation may provide important insight into the biology of colon cancer progression and putative novel therapy options.

Long-term follow-up in 54 surgically treated patients with gastrointestinal stromal tumours

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the alimentary tract. Since these tumours are rather resistant to radiation and conventional chemotherapy, prognosis may be poor. Imatinib, a KIT tyrosine kinase inhibitor, has been shown to have dramatic antitumour effects on GISTs; however, surgical en bloc resection of the tumour with free resection margins remains still the first option for cure.

MATERIALS AND METHODS

Here, we present a retrospective study with 54 consecutive GIST patients who were treated surgically at our University Hospital between 1993 and 2005 and were followed up at 5 and 10 years.

RESULTS

The disease-specific survival rate was 94% at 1 year, 91% at 3 years, 76% at 5 years, and 72% at 10 years. In univariate analysis, tumour size, mitotic rate, morphology, and necrosis predicted survival in patients with negative margins. Age, sex, and symptoms did not influence outcome.

CONCLUSION

GISTs have a high incidence of associated secondary malignancies which may have a significant influence on prognosis and outcome. Patients with R0 resections had a significantly better survival rate of 86% at 5 years and of 81% at 10 years than those with R1 and R2 resections (21% and 0%).

"You can do it late at night or in the morning. You can do it at home, I did it with my flatmate." The educational impact of an OSCE

BACKGROUND

The use of an objective structured clinical examination (OSCE) has been a powerful influence on doctor training but assessments do not always drive study behaviour in predictable ways.

AIMS

To investigate the impact an OSCE has on study behaviours by exploring how 5th year medical students identify what to learn for a summative OSCE and the role of the clinical environment in their preparation.

METHODS

A semi-structured questionnaire survey asked about strategies used by students to prepare for the OSCE. Focus group interviews explored successful methods of preparation for the OSCE. Themes were identified and classified.

RESULTS

The questionnaire response rate was 84%. Topic identification was usually from the list of examinable problems, past OSCE papers and a booklet prepared by a previous student containing a series of OSCE checklists. The study behaviours of students preparing for the OSCE exam were predominantly to practise on each other, and to rehearse routines. Strategic and efficient study habits were favoured over conscious utilization of the clinical environment.

CONCLUSION

The expectation that an OSCE drives learning into the clinical workplace was not supported by this study. This suggests the role of clinical experience in helping students prepare for the exam may be more subliminal, or that an OSCE is more as a test of psychomotor skills than a marker of clinical experience. An unexpected benefit may be to drive more collaborative learning.

Multiple gene expression classifiers from different array platforms predict poor prognosis of colorectal cancer

PURPOSE

This study aimed to develop gene classifiers to predict colorectal cancer recurrence. We investigated whether gene classifiers derived from two tumor series using different array platforms could be independently validated by application to the alternate series of patients.

EXPERIMENTAL DESIGN

Colorectal tumors from New Zealand (n = 149) and Germany (n = 55) patients had a minimum follow-up of 5 years. RNA was profiled using oligonucleotide printed microarrays (New Zealand samples) and Affymetrix arrays (German samples). Classifiers based on clinical data, gene expression data, and a combination of the two were produced and used to predict recurrence. The use of gene expression information was found to improve the predictive ability in both data sets. The New Zealand and German gene classifiers were cross-validated on the German and New Zealand data sets, respectively, to validate their predictive power. Survival analyses were done to evaluate the ability of the classifiers to predict patient survival.

RESULTS

The prediction rates for the New Zealand and German gene-based classifiers were 77% and 84%, respectively. Despite significant differences in study design and technologies used, both classifiers retained prognostic power when applied to the alternate series of patients. Survival analyses showed that both classifiers gave a better stratification of patients than the traditional clinical staging. One classifier contained genes associated with cancer progression, whereas the other had a large immune response gene cluster concordant with the role of a host immune response in modulating colorectal cancer outcome.

CONCLUSIONS

The successful reciprocal validation of gene-based classifiers on different patient cohorts and technology platforms supports the power of microarray technology for individualized outcome prediction of colorectal cancer patients. Furthermore, many of the genes identified have known biological functions congruent with the predicted outcomes.

Objectivity in objective structured clinical examinations: checklists are no substitute for examiner commitment

PURPOSE

This study explored factors that contribute to objectivity in objective structured clinical examinations (OSCEs). The authors quantified the effect of examiners on interrater reliability and separated this effect from that of station construction, determined the effect of objectification on station reliability and validity, and explored examiner factors that may contribute to interrater reliability.

METHOD

Data came from examiners' mark sheets from four annual OSCEs (1997-2000). The OSCEs were conducted identically and simultaneously at three sites, within the University of Otago medical school in New Zealand, with two examiners at each station. The contribution to interrater correlations of station construction and mark sheet compared with examiners' contribution was partitioned out using a random-effects analysis of variance. For one OSCE, a multiple linear regression was used to determine the independent contributions to interrater reliability of the number of checklist items per mark sheet, examiner experience, and examiner involvement in station construction.

RESULTS

Station construction and mark sheets contributed 10.1% and examiners contributed 89.9% to the variation in interrater reliability. Following multivariate analysis, the number of items per mark sheet was negatively associated, and examiner involvement in station construction was positively associated, with interrater reliability. Examiner experience in examining or in clinical medicine was not associated with interrater reliability. There was a negative, but nonsignificant, correlation between number of items per mark sheet and that station's correlation with the aggregate OSCE mark.

CONCLUSIONS

The contribution of objective mark sheets to objectivity is relatively minor compared with examiners' contribution. Increasing the number of checklist items per mark sheet decreased both reliability and validity. Achieving objectivity requires diligent examiners who are involved in the whole assessment.

The significance of donor leg distal runoff in femorofemoral bypass grafting

BACKGROUND

The aim of this study is to determine if femorofemoral bypass grafting is an effective operation for unilateral iliac occlusive disease, and to assess for factors that may predict a poorer outcome. A retrospective review was conducted of cases identified from a prospective audit database.

METHODS

Information was obtained from the clinical notes of 97 patients who had 100 femorofemoral bypass graft operations. All living patients were invited for assessment which included colour duplex sonography of the graft and measurement of the ankle brachial index.

RESULTS

Using life-table analysis, the five-year graft secondary patency for claudicants was 79% and for those with critical ischaemia 78%. Five-year survival for claudicants was 65% and for those with critical ischaemia, 38%. Poor distal runoff in the infrapopliteal arteries of the donor limb adversely affected graft patency. Graft survival was not affected by the indication for operation, by donor or recipient superficial femoral artery patency, or by the need for endarterectomy, pre-operative angioplasty or the graft material.

CONCLUSIONS

Femorofemoral bypass grafting is the procedure of choice for all patients who require surgical intervention for unilateral iliac occlusion and donor limb distal runoff may be an important determinant of graft patency.

Paediatric renal trauma: caution with conservative management of major injuries

BACKGROUND

The kidney is the most frequently injured abdominal organ in children and controversy surrounds some aspects of management. This study looks at the experience of our institution and reviews the literature towards developing an optimal strategy for managing this common childhood injury.

METHODS

One hundred and forty-two cases of paediatric renal trauma are reported from a catchment population of approximately 240,000 children < 14 years of age over a 12 year period. Injuries were classified into four groups: groups 1 and 2 were regarded as minor injuries (85%) and group 3 and 4 injuries were those with extravasation of urine or pedicle injury (15%).

RESULTS

The male:female ratio was 2:1 with an average age of 8.5 years. Major renal injuries frequently required large amounts of resuscitation fluid. Associated injuries were present in 41% of all cases with an average of two injuries each. With one exception in each case, the development of complications and the need for early surgery were confined to major injuries. There were no long-term complications. The renal loss rate was 2.1%.

CONCLUSIONS

Renal injuries can be usefully classified into major or minor by determining whether extravasation of urine or pedicle injury is present. Minor injuries should be managed conservatively. Major injuries causing ongoing haemorrhage require urgent surgery. Other major injuries should be imaged regularly and patients with more severe urinomas benefit from early elective surgery at 2-5 days. In cases where extravasation of urine has not shown clear evidence of settling by 5 days' elective surgery probably results in less morbidity and fewer complications than protracted conservative treatment.