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Peter J Lunniss

Publications and source records attributed to Peter J Lunniss.

15 recordsLinked to original sources
PubMed2007

A novel technique to identify patients with megarectum.

PURPOSE: Traditional methods of identifying patients with persistent dilation of the rectum, or megarectum, are associated with inherent methodologic limitations. The purpose of this study was to use a barostat to establish criteria for the diagnosis of megarectum and to assess rectal diameter during isobaric (barostat) and volumetric (barium contrast) distention protocols in constipated patients with megarectum on anorectal manometry. METHODS: During fluoroscopic screening, rectal diameter was measured at minimum distending pressure of the rectum, achieved using a barostat. It was also measured during evacuation proctography (volumetric distention). Having established a normal range in 25 healthy volunteers, 30 constipated patients with evidence of megarectum on anorectal manometry (elevated maximum tolerable volume on latex balloon distention) were studied. A further 10 constipated patients without evidence of megarectum were studied (normal rectum). RESULTS: Megarectum was diagnosed when the rectal diameter was greater than 6.3 cm at minimum distending pressure. Rectal diameter at minimum distending pressure was increased in 20 patients (67 percent) with megarectum on anorectal manometry, but was normal in the remaining 10 patients (33 percent) and all patients with a normal rectum on anorectal manometry. Rectal diameter was increased at evacuation proctography in only 15 patients (50 percent) with evidence of megarectum on anorectal manometry. CONCLUSIONS: The prevalence of megarectum is overestimated and underestimated when rectal diameter is assessed using anorectal manometry and contrast studies, respectively. Controlled (pressure-based) distention combined with fluoroscopic imaging allowed accurate identification of patients with megarectum on the basis of a rectal diameter greater than 6.3 cm at the minimum distention pressure. Measurement of rectal diameter at minimum distention pressure may be useful in those patients with an elevated maximum tolerable volume on anorectal manometry when surgery is being contemplated.

Adult↗
PubMed2006

Multimedia article. External pelvic rectal suspension (the express procedure) for internal rectal prolapse, with or without concomitant rectocele repair: a video demonstration.

PURPOSE: Internal rectal prolapse has been proposed as a cause of symptomatic rectal evacuatory dysfunction. Abdominal rectopexy, the standard surgical approach, has significant attendant risk and does not address any concomitant rectocele. This video was designed to demonstrate a novel surgical method that uses porcine collagen implants (Permacol), designed to correct internal rectal prolapse, with or without rectocele. METHODS INCLUSION CRITERIA: severe rectal evacuatory dysfunction refractory to maximal conservative therapy and full-thickness internal rectal prolapse impeding rectal emptying on defecography with or without associated functional rectocoele; normal colonic transit. Patients undergo comprehensive preoperative and postoperative symptomatic assessment and anorectal physiologic testing, including defecography. A crescenteric perineal skin incision allows development of the rectovaginal/rectoprostatic plane to Denonvilliers fascia, with rectal mobilization. A curved tunneller inserted via the perineal wound is guided retropubically to emerge through suprapubic wounds created on each side. Permacol T-strips are sutured to the anterolateral rectal wall bilaterally, upward traction exerted, and the stem of each T-strip is sutured to the suprapubic periosteum, suspending the rectum. Concomitant rectocele is repaired using a Permacol patch in the rectovaginal plane. RESULTS: Short-term results for the "Express" are encouraging with improvement in evacuatory and prolapse symptoms and concomitant anatomic improvement at defecography. CONCLUSIONS: This procedure promises to be an effective technique for managing patients with refractory evacuatory dysfunction secondary to internal rectal prolapse, with or without rectocele.

Collagen↗
PubMed2006

Rectal hyposensitivity.

Rectal hyposensitivity (RH) relates to a diminished perception of rectal distension that is diagnosed during anorectal physiologic investigation. There have been few direct studies of this physiologic abnormality, and its contribution to the development of functional bowel disorders has been relatively neglected. However, it appears to be common in patients with such disorders, being most prevalent in patients with functional constipation with or without fecal incontinence. Indeed, it may be important in the etiology of symptoms in certain patients, given that it is the only "apparent" identifiable abnormality on physiologic testing. Currently, it is usually diagnosed on the basis of elevated sensory threshold volumes during balloon distension in clinical practice, although such a diagnosis may be susceptible to misinterpretation in the presence of altered rectal wall properties, and thus it is uncertain whether a diagnosis of RH reflects true impairment of afferent nerve function. Furthermore, the etiology of RH is unclear, although there is limited evidence to support the role of pelvic nerve injury and abnormal toilet behavior. The optimum treatment of patients with RH is yet to be established. The majority are managed symptomatically, although "sensory-retraining biofeedback" appears to be the most effective treatment, at least in the short term, and is associated with objective improvement in the rectal sensory function. Currently, fundamental questions relating to the contribution of this physiologic abnormality to the development of functional bowel disorders remain unanswered. Acknowledgment of the potential importance of RH is thus required by clinicians and researchers to determine its relevance.

Constipation↗
PubMed2005

Rectal hypersensitivity worsens stool frequency, urgency, and lifestyle in patients with urge fecal incontinence.

PURPOSE: Rectal sensory mechanisms are important in the maintenance of fecal continence. Approximately 50 percent of patients with urge incontinence have lowered rectal sensory threshold volumes (rectal hypersensitivity) on balloon distention. Rectal hypersensitivity may underlie the heightened perception of rectal filling; however, its impact on fecal urgency and incontinence is unknown. This study was designed to investigate the impact of rectal hypersensitivity in patients with urge fecal incontinence. METHODS: Prospective and retrospective audit review of all patients (n = 258) with an intact native rectum referred to a tertiary colorectal surgical center for physiologic investigation of urge fecal incontinence during a 7.5-year period. Patients with urge fecal incontinence who had undergone pelvic radiotherapy (n = 9) or rectal prolapse (n = 6) were excluded. RESULTS: A total of 108 of 243 patients (44 percent) were found to have rectal hypersensitivity. The incidence of anal sphincter dysfunction was equal (90 percent) among those with or without rectal hypersensitivity. Patients with urge fecal incontinence and rectal hypersensitivity had increased stool frequency (P < 0.0001), reported greater use of pads (P = 0.003), and lifestyle restrictions (P = 0.0007) compared with those with normal rectal sensation, but had similar frequencies of incontinent episodes. CONCLUSIONS: Urge fecal incontinence relates primarily to external anal sphincter dysfunction, but in patients with urge fecal incontinence, rectal hypersensitivity exacerbates fecal urgency, and this should be considered in the management and surgical decision in patients who present with fecal incontinence.

Adult↗
PubMed2005

Rectal intussusception: characterization of symptomatology.

PURPOSE: Rectal intussusception is a common finding at evacuation proctography; however, its significance has been debated. This study was designed to characterize clinically and physiologically a large group of patients with rectal intussusception and test the hypothesis that certain symptoms are predictive of this finding on evacuation proctography. METHODS: A total of 896 patients underwent evacuation proctography from which three groups were identified: those with isolated rectal intussusception (n = 125), those with isolated rectocele (n = 100), and those with both abnormalities (n = 152). Multivariate analyses were used to identify symptoms predictive of findings by evacuation proctography. RESULTS: The symptoms of anorectal pain and prolapse were highly predictive of the finding of isolated intussusception over rectocele (odds ratio, 3.6, P = 0.006; odds ratio, 4.9, P < 0.001) or combined intussusception and rectocele (odds ratio, 2.9, P = 0.02; odds ratio, 2.4, P = 0.03). The symptom of "toilet revisiting" was associated with the finding of rectoanal intussusception (odds ratio, 3.55, P = 0.04). Although patients with mechanically obstructing intussuscepta evacuated slower and less completely (P < 0.001) than those with nonobstructing intussuscepta, no symptom was predictive of this finding on evacuation proctography. CONCLUSIONS: Although certain symptoms are predictive of the finding of rectal intussusception, there is a wide overlap with symptoms of rectocele, another common cause of evacuatory dysfunction. Furthermore, the observation that "obstruction to evacuation" made on proctography had no impact on the incidence of evacuatory symptoms suggests that beyond simply demonstrating the presence of an intussusception, analysis of proctography and subclassifying intussusception morphology seems of little clinical significance, and selection for surgical intervention on the basis of proctographic findings may be illogical.

Adolescent↗
PubMed2005

Systematic review of surgical options for idiopathic megarectum and megacolon.

OBJECTIVE: A subgroup of patients with intractable constipation has persistent dilatation of the bowel, which in the absence of an organic cause is termed idiopathic megabowel (IMB). The aim of this systematic review was to evaluate the published outcome data of surgical procedures for IMB in adults. METHODS: Electronic searches of the MEDLINE (PubMed) database, Cochrane Library, EMBase, and Science Citation Index were performed. Only peer-reviewed articles of surgery for IMB published in the English language were evaluated. Studies of all surgical procedures were included, providing they were performed on 3 or more patients, and overall success rates were documented. Studies were critically appraised in terms of design and methodology, inclusion criteria, success, mortality and morbidity rates, and functional outcomes. RESULTS: A total of 27 suitable studies were identified, all evidence was low quality obtained from case series, and there were no comparative studies. The studies involved small numbers of patients (median 12, range 3-50), without long-term follow-up (median 3 years, range 0.5-7). Inclusion of subjects, methods of data acquisition, and reporting of outcomes were extremely variable. Subtotal colectomy was successful in 71.1% (0%-100%) but was associated with significant morbidity related to bowel obstruction (14.5%, range 0%-29%). Segmental resection was successful in 48.4% (12.5%-100%), and recurrent symptoms were common (23.8%). Rectal procedures achieved a successful outcome in 71% to 87% of patients. Proctectomy, the Duhamel, and pull-through procedures were associated with significant mortality (3%-25%) and morbidity (6%-29%). Vertical reduction rectoplasty (VRR) offered promising short-term success (83%). Pelvic-floor procedures were associated with poor outcomes. A stoma provided a safe alternative but was only effective in 65% of cases. CONCLUSIONS: Outcome data of surgery for IMB must be interpreted with extreme caution due to limitations of included studies. Recommendations based on firm evidence cannot be given, although colectomy appears to be the optimum procedure in patients with a nondilated rectum, restorative proctocolectomy the most suitable in those with dilatation of the colon and rectum, and VRR in those patients with dilatation confined to the rectum. Appropriately designed studies are required to make valid comparisons of the different procedures available.

Adolescent↗
PubMed2005

Rectal hyposensitivity: a disorder of the rectal wall or the afferent pathway? An assessment using the barostat.

OBJECTIVES: Rectal hyposensitivity (RH) relates to a diminished perception of rectal distension. Diagnosis on the basis of abnormal threshold volumes on balloon distension alone may be inaccurate due to the influence of differing rectal wall properties. The aim of this study was to investigate whether RH was actually due to impaired afferent nerve function or whether it could be secondary to abnormalities of the rectal wall. METHODS: A total of 50 patients were referred consecutively to a tertiary referral unit for physiologic assessment of constipation (Rome II criteria), 25 of whom had associated fecal incontinence. Thirty patients had RH (elevated threshold volumes on latex balloon distension), and 20 patients had normal rectal sensation (NS). Results were compared with those obtained in 20 healthy volunteers (HV). All subjects underwent standard anorectal physiologic investigation, and assessment of rectal compliance, adaptive response to isobaric distension at urge threshold, and postprandial rectal response, using an electromechanical barostat. RESULTS: Mean rectal compliance was significantly elevated in patients with RH compared to NS and HV (p < 0.001). However, 16 patients with RH (53%) had normal compliance. Intensity of the urge to defecate during random phasic isobaric distensions was significantly reduced in patients with RH compared to NS and HV (p < 0.001). The adaptive response at urge threshold was reduced in patients with RH compared to NS and HV (p < 0.001), although spontaneous adaptation at operating pressure was similar in all three groups studied (p= 0.3). Postprandially, responses were similar between groups. CONCLUSIONS: In patients found to have RH on simple balloon distension, impaired perception of rectal distension may be partly explained in one subgroup by abnormal rectal compliance. However, a second subgroup exists with normal rectal wall properties, suggestive of a true impairment of the afferent pathway. The barostat has an important role in the identification of these subgroups of patients.

Adult↗
PubMed2005

Rectal intussusception: a study of rectal biomechanics and visceroperception.

OBJECTIVES: Rectal intussusception (RI) is a significant cause of morbidity amongst those with a rectal evacuatory disorder. The pathophysiology is unknown, but may involve abnormal biomechanics of the rectal wall similar to that previously demonstrated in patients with overt rectal prolapse (RP). Using an electromechanical barostat, this study aimed to investigate the biomechanics and visceroperception of the rectal wall in patients with RI. METHODS: Twenty consecutive patients (12 females, median age 46 yr (range 24-66)) with symptomatic, full-thickness RI were studied. Patients underwent assessment of rectal compliance, visceroperception, adaptive response to isobaric distension at urge threshold, and assessment of the postprandial response. Results were compared with those obtained in 28 asymptomatic volunteers, 10 with RI (6 females, median age 29 yr (range 21-36)) and 18 (9 females, median age 33 yr (range 21-62)) without. RESULTS: In the absence of the clinical finding of solitary rectal ulcer syndrome (SRUS), patients with symptomatic RI have normal rectal wall biomechanics, as do asymptomatic volunteers with RI (p < 0.05). Patients with the clinical finding of SRUS had reduced compliance and adaptation. In all three groups, there was a linear relationship between rectal pressure and visceroperception. The postprandial contractile response was similar between groups. CONCLUSIONS: Patients with RI have normal rectal wall biomechanics. This is in contrast to patients with RP, and suggests that while they may represent different stages of the same disease process, they are physiologically distinct. In patients with RI and SRUS, rectal wall inflammation and fibrosis, perhaps arising secondary to the intussusception, may explain the physiological changes observed.

Adaptation, Physiological↗
PubMed2004

Anal sphincter morphology in patients with full-thickness rectal prolapse.

PURPOSE: The aim of this study was to assess the morphologic change of the anal canal in patients with rectal prolapse. METHODS: The endoanal ultrasound scans of 18 patients with rectal prolapse were compared with those of 23 asymptomatic controls. The thickness and area of the internal anal sphincter and submucosa were measured at three levels. RESULTS: Qualitatively, patients with rectal prolapse showed a characteristic elliptical morphology in the anal canal with anterior/posterior submucosal distortion accounting for most of the change. Quantitatively, internal anal sphincter (IAS) and submucosa (SM) thicknesses and area were greater in all quadrants of the anal canal (especially upper) in patients with rectal prolapse compared with controls. There was statistical evidence (in a regression model) of a relationship between increases in all measured variables and the finding of rectal prolapse. CONCLUSIONS: The cause of sphincter distortion in rectal prolapse is unknown but may be a response to increased mechanical stress placed on the sphincter from the prolapse or an abnormal response by the sphincter complex to the prolapse. Patients found to have this feature on endoanal ultrasound should undergo clinical examination and defecography to look for rectal wall abnormalities.

Adult↗
PubMed2004

Risk factors in acquired faecal incontinence.

Acquired faecal incontinence arising in the non-elderly population is a common and often devastating condition. We conducted a retrospective cohort analysis in 629 patients (475 female) referred to a tertiary centre, to determine the relative importance of individual risk factors in the development of faecal incontinence, as demonstrated by abnormal results on physiological testing. Potential risk factors were identified in all but 6% of patients (7 female, 32 male). In women, the principal risk factor was childbirth (91%), and in most cases at least one vaginal delivery had met with complications such as perineal injury or the need for forceps delivery. Of the males, half had undergone anal surgery and this was the only identified risk factor in 59%. In many instances, assignment of cause was hampered by a long interval between the supposed precipitating event and the development of symptoms. Abnormalities of anorectal physiology were identified in 76% of males and 96% of females (in whom they were more commonly multiple). These findings add to evidence that occult damage to the continence mechanism, especially through vaginal delivery and anal surgery, can result in subsequent faecal incontinence, sometimes after an interval of many years.

Adolescent↗
PubMed2003

Smooth muscle cholinergic denervation hypersensitivity in diverticular disease.

BACKGROUND: Evidence from clinical and laboratory investigations into the causes of diverticular disease suggests that disturbances in cholinergic activity are important, the effector mechanisms of which have yet to be established. We aimed to investigate the role of smooth muscle and neural cholinergic activity in the pathogenesis of this disease. METHODS: Two investigators independently did a blinded immunohistochemical image analysis of localising antibodies to choline acetyltransferase, co-localised with protein gene product (PGP)--a marker of general neural tissue-and smooth muscle muscarinic M3 receptors, on three histological sections of sigmoid colons from ten patients with diverticular disease and ten controls, after resections for rectal tumours. We also did isotonic organ bath experiments to assess muscle strip sensitivities to exogenous acetylcholine. FINDINGS: In circular muscle, activity of choline acetyltransferase was lower in patients with diverticular disease than in controls: median percentage surface area of choline acetyltransferase over PGP was 17.5% (range 10.0-37.0) in patients with diverticular disease and 47.0% (29.0-54.0) in controls (p<0.0001). M3 receptors were upregulated in patients with diverticular disease compared with controls: the median surface area was 13.2% (6.0-23.3) in patients with diverticular disease and 2.5% (1.6-3.7) in controls (p<0.0001). The sensitivity to exogenous acetylcholine was increased in patients with diverticular disease (mean -log EC(50) 5.6 [SD 0.3]) compared with controls (4.9 [0.5]; difference 0.7 [95% CI 0.3-1.1], p=0.006). In longitudinal muscle, choline acetyltransferase activity was lower in patients with diverticular disease (median 19.5%, range 12.0-30.0) than in controls (47.0%, 35.0-60.0; p<0.0001), with upregulation of M3 receptors in diverticular disease (diverticular disease 7.8% [1.9-20.4], controls 1.7% [0.8-3.0]; p<0.0001). However, sensitivity to exogenous acetylcholine did not differ between the two groups (diverticular disease mean 5.6% [SD 0.3], controls 5.2% [0.4]; difference 0.4% [95% CI -0.02-0.7], p=0.06). INTERPRETATION: Our results suggest that cholinergic denervation hypersensitivity can affect smooth muscle. Upregulation of smooth muscle M3 receptors might account for specific clinical, physiological, and pharmacological abnormalities associated with diverticular disease.

Acetylcholine↗
PubMed2003

Rectal hyposensitivity: prevalence and clinical impact in patients with intractable constipation and fecal incontinence.

PURPOSE: Blunted rectal sensation, or rectal hyposensitivity, has been reported anecdotally in patients with functional disorders of evacuation and continence. The purpose of this study was to determine the prevalence of rectal hyposensitivity and whether the finding of such an abnormality was associated with any clinical impact. METHODS: One thousand three hundred fifty-one patients, referred for anorectal physiologic investigation, were divided according to presenting symptoms into the following categories: constipation (subdivided into infrequency of and/or obstructed defecation), fecal incontinence (subdivided into passive, postdefecation, and urge incontinence), fecal incontinence and constipation, or "other." Rectal hyposensitivity was judged to be present when at least one of the sensory threshold volumes was elevated beyond the normal range (mean plus 2 standard deviations). The prevalence of rectal hyposensitivity was then calculated in each group and in relation to other investigations. RESULTS: Rectal hyposensitivity was present in 16 percent of patients, with males and females equally affected. Twenty-three percent of patients with constipation, 10 percent of patients with fecal incontinence, 27 percent of patients with incontinence associated with constipation, and only 5 percent of patients with other symptoms were found to have rectal hyposensitivity. In patients with obstructed defecation, rectal hyposensitivity was present in 33 percent with rectocele, 40 percent with intussusception, and 53 percent with no mechanical obstruction evident on evacuation proctography. CONCLUSION: Rectal hyposensitivity is common in patients with constipation and/or fecal incontinence and may thus be important in the etiology of such conditions. Although the clinical relevance of this physiologic abnormality is unknown, its presence may have implications regarding the management of hindgut dysfunction and particularly the selection of patients for surgery.

Adolescent↗
PubMed2003

Rectal heat thresholds: a novel test of the sensory afferent pathway.

PURPOSE: Currently, rectal sensation may be measured by balloon distention or mucosal electrostimulation. This study investigated the application of a graded heat stimulus to the rectum using a novel thermal probe as a further method of evaluating rectal sensory afferent mechanisms. METHODS: A thermal probe specially designed in our institution was used to test rectal heat sensitivity in 31 healthy subjects. This was compared with all other standard anorectal physiologic measurements. Repeatability studies were also performed. RESULTS: Heat stimulation of the mid rectum elicited sensory responses in all subjects. The most common reported response was not heat but a sharp or prickling sensation. The median rectal heat threshold was similar in males (median, 47 degrees C; range, 44-50 degrees C) compared with females (median, 45 degrees C; range, 43-50 degrees C; P > 0.05). There was a high degree of repeatability with rectal heat and balloon distention thresholds, but not electrostimulation thresholds. A strong correlation was found between rectal heat thresholds and defecatory desire (r = 0.71; P < 0.001) and maximum tolerable volumes (r = 0.8; P < 0.001) measured with balloon distention. CONCLUSION: This is the first demonstration of a repeatable sensory response to heat stimulation in the rectum of normal subjects. Strong correlation between heat thresholds and balloon distention to maximum tolerable volumes and defecatory desire suggest common sensory afferent pathway excitation. Heat stimulation is a simple technique that has a high degree of repeatability and may be an objective assessment of polymodal nociceptor function in the rectum.

Adolescent↗