Systematic review of the clinical effectiveness of neuromodulation in the treatment of faecal incontinence.

BACKGROUND: Over the past 18 years neuromodulation therapies have gained support as treatments for faecal incontinence (FI); sacral nerve stimulation (SNS) is the most established of these. A systematic review was performed of current evidence regarding the clinical effectiveness of neuromodulation treatments for FI. METHODS: The review adhered to the PRISMA framework. A comprehensive search of the literature included PubMed, MEDLINE, Embase and Evidence-Based Medicine Reviews. Methodological quality assessment and data extraction were completed in a systematic fashion. RESULTS: For SNS, 321 citations were identified initially, of which 61 studies were eligible for inclusion. Of studies on other neuromodulation techniques, 11 were eligible for review: seven on percutaneous tibial nerve stimulation (PTNS) and four on transcutaneous tibial nerve stimulation (TTNS). On intention-to-treat, the median (range) success rates for SNS were 63 (33-66), 58 (52-81) and 54 (50-58) per cent in the short, medium and long terms respectively. The success rate for PTNS was 59 per cent at the longest reported follow-up of 12 months. SNS, PTNS and TTNS techniques also resulted in improvements in Cleveland Clinic Incontinence Score and quality-of-life measures. Despite significant use of neuromodulation in treatment of FI, there is still no consensus on outcome reporting in terms of measures used, aetiologies assessed, length of follow-up or assessment standards. CONCLUSION: Emerging data for SNS suggest maintenance of its initial therapeutic effect into the long term. The clinical effectiveness of PTNS is comparable to that of SNS at 12 months, although there is no evidence to support its continued effectiveness after this period. PTNS may be a useful treatment before SNS. The clinical effectiveness of TTNS is still uncertain owing to the paucity of available evidence. A consensus to standardize the use of outcome measures is recommended in order that further reports can be compared meaningfully.

Local recurrence after curative resection for rectal cancer is associated with anterior position of the tumour.

BACKGROUND: Mobilization of rectal cancer can be difficult if the tumour is located anteriorly and may result in a higher incidence of local recurrence. The aim of this study was to determine whether local recurrence and survival following curative resection of rectal cancer were associated with the position of the tumour. METHODS: Data were drawn from a comprehensive, prospective hospital registry of all resections for rectal cancer from January 1990 to December 1998, with follow-up to December 2003. RESULTS: The 5-year local recurrence rate was 15.9 (95 per cent confidence interval (c.i.) 11.0 to 22.8) per cent in 176 patients with tumours that had an anterior component compared with 5.8 (95 per cent c.i. 2.8 to 11.9) per cent in 132 patients with tumours without an anterior component (P = 0.009). This association persisted after adjustment for other factors linked to local recurrence (hazard ratio (HR) 2.4 (95 per cent c.i. 1.1 to 5.4)). Similarly, anterior position had a significant negative independent association with survival (HR 1.4 (95 per cent c.i. 1.0 to 2.00)). CONCLUSION: Anterior position is an independent negative prognostic factor for both local recurrence and survival after curative resection of rectal cancer.

The evolving role of gene-based treatment in surgery.

BACKGROUND: The completion of the sequencing of the human genome in 2003 marked the dawn of a new era of human biology and medicine. Although these remarkable scientific advances improve the understanding of human biology, the question remains how this rapidly expanding knowledge of functional genomics affects the role of surgeons. This article reviews the potential therapeutic application of gene therapy for various surgical conditions. METHODS: The core of this review was derived from a Medline database literature search. RESULTS AND CONCLUSION: The currently available vectors in the field of gene therapy and their limitations for clinical applications were analysed. The achievements of gene therapy in clinical trials and the future ramifications for surgery were also explored. Whether gene therapy takes a major role in surgical practice will depend greatly on the success of future vector development. Advances in viral vector technology to reduce the inflammatory effect, and improvements in the efficiency of gene delivery using non-viral vector technology, would allow this form of therapy to become more clinically applicable.

Radiological appearances in the pelvis following rectal cancer surgery.

Radiology has a significant role in the evaluation of surgery for rectal cancer. With recent developments in surgical techniques, the number of neorectal reservoir configurations has increased. It is important to recognize the normal and abnormal appearances, both early and late, following pelvic surgery. The aim of this pictorial review is to demonstrate the imaging techniques that are used in both the investigation and the follow-up of patients who have undergone uncomplicated or complicated rectal resection.

Contribution of the pudendal nerve to sensation of the distal rectum.

BACKGROUND: Anal and rectal sensory mechanisms and pudendal nerve function are important in the control of faecal continence. The contribution of the pudendal nerve to sensation of the distal rectum was investigated. METHODS: Heat thresholds in the anal canal, distal and mid rectum were measured using a specially designed thermoprobe. Rectal sensory threshold volumes were measured using the balloon distension method. Needle electrodes were inserted into the external anal sphincter. Pudendal nerve block was performed through a perineal approach, and completeness assessed by loss of electromyographic activity. Heat and rectal volume thresholds were measured again following unilateral and bilateral pudendal nerve block. RESULTS: The technique was successful in four of six volunteers. Bilateral pudendal nerve block produced complete anaesthesia to heat in the anal canal (P = 0.029), but had no effect on heat thresholds in the distal or mid rectum. Rectal sensory threshold volumes were also unaffected by pudendal nerve anaesthesia. CONCLUSION: Anal canal sensation is subserved by the pudendal nerve, but this nerve is not essential to nociceptive sensory mechanisms in the distal or mid rectum. The transition between visceral control mechanisms in the lower rectum and somatic mechanisms in the anal canal may have functional importance in the initiation of defaecation and the maintenance of continence.

The surgical management of haemorrhoids--a review.

A number of new surgical treatments have led to a reappraisal of haemorrhoid disease over the last few decades. Despite a range of treatment modalities, the options are limited in their effectiveness and can lead to a number of complications. An inadequate classification system based on appearance rather than symptoms makes the choice of appropriate therapy difficult. More recent techniques have led to a move away from surgical excision. However, further research is required to establish their precise indications and long-term efficacy.

What factors influence survival in patients with unresected synchronous liver metastases after resection of colorectal cancer?

OBJECTIVE: The aim of this study was to determine whether the survival of patients with untreated synchronous liver metastases after resection of a colorectal cancer was associated with any features of the primary tumour. METHODS: Information for 398 consecutive patients with unresected liver metastases in the period 1971-2001 was examined by multivariate survival analysis. RESULTS: Of 19 clinical and pathological variables considered, survival was independently associated only with residual tumour in a line of resection (hazard ratio (HR) 1.95), venous invasion (HR 1.87), right colonic tumour (HR 1.68), lymph node metastasis (HR 1.54), and extra-hepatic metastasis (HR 1.16); 8.3% of patients had none of these adverse features. Their 2-year overall survival rate was 39.2%, compared with only 16.5% (P < 0.001) in those with one or more adverse features. CONCLUSIONS: These findings may assist in selecting patients most likely to benefit from treatment of hepatic metastases and in counselling patients and their relatives.

Sensory fibres expressing capsaicin receptor TRPV1 in patients with rectal hypersensitivity and faecal urgency.

BACKGROUND: Faecal urgency and incontinence with rectal hypersensitivity is a distressing, unexplained disorder that is inadequately treated. We aimed to determine whether expression of the heat and capsaicin receptor vanilloid receptor 1 (TRPV1 or VR1) was changed in rectal sensory fibres, and to correlate nerve fibre density with sensory abnormalities. METHODS: We compared full-thickness rectal biopsy samples from nine patients with physiologically characterised rectal hypersensitivity with tissue samples from 12 controls. Sensory thresholds to rectal balloon distension and heating the rectal mucosa were measured before biopsy. We assessed specimens with immunohistochemistry and image analysis using specific antibodies to TRPV1; nerve growth factor (NGF) receptor tyrosine kinase A; glial cell line-derived neurotrophic factor (GDNF); neuropeptides calcitonin gene-related peptide (CGRP) and substance P; the related vanilloid receptor-like protein (VRL) 2; glial markers S-100 and glial fibrillary acid protein (GFAP); and the nerve structural marker peripherin. FINDINGS: In rectal hypersensitivity, nerve fibres immunoreactive to TRPV1 were increased in muscle, submucosal, and mucosal layers: in the mucosal layer, the median% area positive was 0.44 (range 0.30-0.59) in patients who were hypersensitive and 0.11 (0.00-0.21) in controls (p=0.0005). The numbers of peripherin-positive fibres also increased in the mucosal layer (hypersensitive 3.00 [1.80-6.50], controls 1.20 [0.39-2.10]: (p=0.0002). The increase in TRVP1 correlated significantly with the decrease in rectal heat (p=0.03) and the distension (p=0.02) sensory thresholds. The thresholds for heat and distension were also significantly correlated (p=0.0028). Expression of nerve fibres positive for GDNF (p=0.001) and tyrosine kinase A (p=0.002) was also increased, as were cell bodies of the submucosal ganglia immunoreactive to CGRP (p=0.0009). INTERPRETATION: Faecal urgency and rectal hypersensitivity could result from increased numbers of polymodal sensory nerve fibres expressing TRPV1. The triggering factor or factors remain uncertain, but drugs that target nerve terminals that express this receptor, such as topical resiniferatoxin, deserve consideration.