Maximum Anal Resting Pressure Research Articles

Anal canal and sphincter function in children with Hirschsprung disease after definitive surgery

IntroductionAnorectal manometry may be useful to objectively evaluate anorectal function following definitive pullthrough for Hirschsprung Disease (HD) but there is little published data. Our study aims to investigate anorectal manometry findings and their association with bowel function. MethodologyThis was a prospective observational study. Convenience sampling method was used to recruit all HD patients who had definitive pullthrough from January 2019 to December2020 in our institution. High-resolution anorectal manometry (HRAM) was used to record anal resting pressure (ARP), length of high-pressure zone (HPZ), and presence/absence of recto-anal inhibitory reflex (RAIR). The Paediatric Incontinence/Constipation Scoring System (PICSS) was scored for all participants. PICSS is a validated questionnaire with scores mapped to an age-specific normogram to denote constipation, incontinence, and their combinations. Non-parametric and chi-square tests at significance p<0.05 were conducted to examine the relationship between PICSS categories and manometry findings. Ethical approval was obtained. ResultsThere were 32 participants (30 boys). Median age at participation was 26.5 months (range: 13.8–156). Twenty-four (75%) had transanal pullthrough, 8(25%) underwent Duhamel procedure. PICSS scored 10(31.3%) as normal, 8(25%) as constipation, 10(31.3%) as incontinent, and 4(12.5%) as mixed. RAIR was present in 12 patients (37.5%). HPZ, maximum ARP, mean ARP were comparable across all PICSS groups without statistically significant differences. Presence of RAIR was not significantly associated with any PICSS groups (p = 0.13). ConclusionBowel function does not appear to be significantly associated with HRAM findings after definitive pullthrough for HD, but our study is limited by small sample size. RAIR was present in 37.5% patients after pullthrough. Level of EvidenceLevel II

Normal values for solid state high resolution anorectal manometry in healthy adult volunteers

Objective: To explore the normal values for two-dimension solid state high resolution anorectal manometry (HRAM) in healthy adult volunteers. Methods: The healthy adult volunteers were recruited by advertisement and underwent solid state HRAM in the left lateral position. Anorectal pressures and rectal sensation were recorded and analyzed. Results: (1) A total of 126 Chinese healthy adult volunteers (male: 50 cases (39.7%); age: (37.5±14.2) years old ) were recruited in this study. (2) Mean anal resting pressure (MERP) was (71.8±17.3) mmHg (1 mmHg=0.133 kPa). Maximum anal resting pressure (MARP) was (79.3±17.8) mmHg, Maximum anal squeeze pressure (MSP) was (178.7±52.8) mmHg. Anal high pressure zone (HPZ) length was (3.4±0.6) cm. During simulated evacuation, residual anal pressure (RAP) was (63.8±20.5) mmHg, and anal relaxation rate (ARR) was (37.0±11.5)%. Rectal threshold volume for first sensation (FST), desire to defecate (DDT), urgency to defecate (UDT) and maximum discomfort (MDT) was (47.4±10.0) ml, (84.5±18.2) ml, (125.8±28.5) ml, and (175.5±36.1) ml, respectively. (3) Compared with female subjects, male subjects had higher MSP[(211.0±50.7) mmHg vs (157.5±42.5) mmHg], RAP[(71.6±18.1) mmHg vs (58.8±20.5) mmHg]and rectal MDT[(187.0±36.4) mmHg vs (168.0±34.1)mmHg], but lower ARR[(32.1±8.0)% vs (40.2±12.3)%], all P<0.01. (4) MERP, MARP, MSP and rectal MDT were higher in young group (≤40 years old), all P<0.05. Conclusions: These observations provide normal values for two-dimension solid state HRAM, which have significant difference between genders and different age groups.

A multi-center, randomized, double-blind, placebo-controlled trial of glyceryl trinitrate ointment in the treatment of anal fissure

To evaluate the clinical efficacy and safety of glyceryl trinitrate (GTN) ointment in the treatment of anal fissure. In this multi-center, randomized, double-blind and placebo-controlled trial, 240 chronic anal fissure patients from 7 clinical centers were randomized to receive eight-week treatment with GTN ointment (treatment group) or vaseline ointment (control group) respectively. Healing rate, visual analogue score (VAS), maximum anal resting pressure (MARP) and adverse reactions were recorded and compared. A total of 221 patients (92.1%) finished the trial, including 114 patients in treatment group (95.0%, 114/120) and 107 in control group (89.2%, 107/120). At the endpoint of treatment (56 d), 90 patients in treatment group (78.9%, 90/114) healed completely compared to 31 patients in control group (29.0%, 31/107), and decrease rates of VAS in the two groups were (94.8±15.7)% and (61.2±35.7)% respectively, both differences were statistically significant (P<0.01). MARP after first administration was (20.2±18.5) mm Hg in treatment group (n=12) and (7.1±14.7) mm Hg in control group (n=6), which was not significantly different (P=0.152). Adverse reaction incidence was higher in treatment group (42.1% vs. 9.3%, P<0.05), while these adverse reactions were mainly headache and fullness in head, which were self-limiting. GTN ointment can effectively promote healing and relieve pain in anal fissure with safety and tolerance.

Importance of anorectal manometry after definitive surgery for Hirschsprung′s disease in children

The purpose of this investigation is to evaluate anorectal function after definitive surgery for Hirschsprung's disease (HD) by anorectal manometry. We evaluated the anorectal manometric assessment of 18 children who were operated for HD. Functional outcomes were determined by a questionnaire. Rectoanal inhibitory reflex (RAIR) and maximum anal resting pressure (MARP) were monitored. The results were compared between obstructive patients and asymptomatic patients. The median age at definitive operation was 19 months (range 12-72 months). Anorectal manometry was performed in 14 male and 4 female patients. All the cases underwent three staged procedure for HD and modified Duhamel procedure was performed as definitive procedure for all the patients. Mean age was 4.3 months (range 25 days to 5 years) at time of diagnosis. Post-operative enterocolitis or severe constipation was observed in seven patients (38.8%). There were no patients with incontinence. Eighteen patients underwent anorectal manometry meanly 2 years after definitive operation. RAIR was absent in 14 (77.7%) patients and abnormal in 4 (22.2%). There were no significant differences in the MARP values between symptomatic and asymptomatic patients. The results of our study showed that the majority of the patients have impaired anorectal motility. There were no significant differences in the results of the functional studies for the seven patients with symptoms of obstruction or constipation when compared with asymptomatic patients after surgery for HD.

Fissurectomy and anal advancement flap for anterior chronic anal fissure without hypertonia of the internal anal sphincter in females

Lateral internal sphincterotomy is considered the surgical treatment of choice for chronic anal fissure after failure of medical therapy but it risks continence. The aim of the study was to evaluate fissurectomy with advancement flap for anterior chronic anal fissure (CAAF) resistant to medical therapy. Sixteen women with CAAF without hypertonia of the internal anal sphincter, unresponsive to previous medical treatment, were included in the study. Absence of hypertonia was defined as a maximum anal resting pressure (MRP) of less than 85 mmHg. All patients underwent fissurectomy with an advancement skin flap. Complete healing occurred in all patients within 30 days. The intensity and the duration of pain after defecation reduced from the first postoperative defecation. MRP before surgery and at 6 months showed no significant difference. At 1 month, four patients experienced a continence disturbance, two of whom had it preoperatively. At 12 months, two (12.5%) patients continued to experience a continence disturbance. Fissurectomy with skin advancement flap resulted in complete healing and full relief of symptoms in all patients. There was a low incidence of continence disturbance.

The effect of neo-rectal wall properties on functional outcome after colonic J-pouch-anal anastomosis

Background/aimsIt has been suggested that normal function of both anal sphincters is essential for a good functional outcome after colonic J-pouch-anal anastomosis (CPAA). However, CPAA patients may have impaired continence despite adequate sphincter function. The present study was designed to identify those factors, which contribute to the functional outcome after a handsewn CPAA.Materials and methodsForty patients were studied before and 1 year after pouch surgery. Faecal continence was evaluated using the Rockwood faecal incontinence severity index (RFISI). At both occasions, maximum anal resting pressure (MARP) and maximum anal squeeze pressure (MASP) were recorded. In addition, sensory perception threshold-volumes (SPT-V) and compliance were assessed using an ‘infinitely’ compliant polyethylene bag connected to an electronic barostat assembly.ResultsThe median RFISI score 1 year after surgery was higher than the median RFISI score before surgery (13 vs 7 (p < 0.01). The median MARP dropped significantly (p < 0.01) whereas the median MASP remained unaffected. The mean compliance, calculated at three different sensation levels, and the pouch sensory perception threshold-volumes (PSPT-V) were lower than those of the original rectum (p < 0.05). The reduction of MARP showed no correlation with the post-operative change in RFISI scores. Low PC and low PSPT-V were associated with higher RFISI scores.ConclusionLow pouch compliance and low SPT-V adversely affect functional outcome after a handsewn colonic J-pouch-anal anastomosis.

Use of glyceryl trinitrate ointment in the treatment of anal fissure

Anal fissure is often treated surgically by sphincterotomy. There is growing concern over the effects of this procedure on continence. Nitric oxide donors such as glyceryl trinitrate are thought to cause a reversible 'chemical sphincterotomy', capable of healing the fissure. Twenty-one consecutive patients with chronic anal fissure (13 women, mean age 36 years) were treated for 4-6 weeks with 0.2 per cent glyceryl trinitrate ointment applied to the fissure twice daily. Maximum anal resting pressure (MARP) was measured before and after application of the ointment at the first visit. There were 16 posterior and five anterior fissures. Mean(s.d.) MARP fell from 118.7(45.0) to 70.3(34.1) cmH2O over 20 min after application of the ointment (P < 0.001). Healing was complete in 11 patients at 4 weeks and in 18 at 6 weeks. The fissure recurred in four patients after cessation of treatment; three were successfully treated by further glyceryl trinitrate. Mild headache occurred in four patients. Anal fissure can be successfully treated with 0.2 per cent glyceryl trinitrate ointment applied topically.

Topical nitroglycerin versus lateral internal sphincterotomy for chronic anal fissure: prospective, randomized trial

Topical nitroglycerin (GTN) is one of the medical treatments of choice in chronic anal fissure. The present prospective, randomized, clinical trial was conducted to study the symptomatic relief, healing, and changes in the maximum anal resting pressure (MARP) in patients with chronic anal fissure comparing topical GTN and lateral sphincterotomy. Forty consecutive patients with chronic anal fissure were randomized for treatment with either topical GTN or internal sphincterotomy (20 patients in each group). Anal manometry was done before treatment in all patients, and 1 h after application of GTN or sphincterotomy. Patients were followed at 2-weekly intervals for 6 weeks for symptomatic relief and healing. Both GTN and sphincterotomy brought about a highly significant, but comparable drop in the MARP after treatment (P < 0.0001 in both groups). Sphincterotomy relieved pain much earlier compared to GTN (70% vs 40% at 2 weeks, P = 0.0032); but after 4 weeks of treatment, pain relief in both groups was comparable. Healing in the sphincterotomy group was also earlier than with GTN (55% vs 0% at 2 weeks, P < 0.0001; and 85% vs 30% at 4 weeks, P < 0.0001); but after 6 weeks, healing in both groups was comparable. Sphincterotomy had a significant incidence of minor, short-term complications; it also required surgical expertise, theatre time, and day-care beds. Nitroglycerin is safe, with mild and tolerable side-effects of headache and local burning sensation. Topical GTN should be the initial treatment in chronic anal fissure. Lateral sphincterotomy should be reserved for patients with severe disabling pain (because pain relief is much faster), and for patients not responding to at least 4 weeks of GTN therapy.

Botulinum toxin injection inhibits myogenic tone and sympathetic nerve function in the porcine internal anal sphincter.

Botulinum toxin is an effective treatment for anal fissure, though there is a lack of agreement over the optimal site for its injection. This reflects our current ignorance of its mechanism, and whether it has any action on the nerves of the internal anal sphincter (IAS). This study set out to resolve this issue through use of a pig model. Eight pigs were studied in pairs: one of each pair received a botulinum toxin injection into the anal sphincter, whilst the other acted as its control. Manometry was performed every two weeks under anaesthesia. Pigs were slaughtered at between four and six weeks after injection and the properties of the IAS compared in vitro. Whilst maximum anal resting pressure (MARP) increased slowly in control pigs during the experimental period, reflecting weight gain, a fall was observed in treated pigs. In vitro, IAS strips from control pigs generated 400 mg of spontaneous tone per gram of tissue (+/- 45; standard error), compared to 250 (+/- 25) mg/g tissue from treated pigs (P < 0.01). Electric Field Stimulation at 50 Hz produced 150 (+/- 22) mg contraction/gram tissue in IAS strips from control pigs compared to 53 (+/- 13) mg/g tissue in treated pigs (P < 0.0005). This contractile response was blocked by guanethidine. Botulinum toxin has a significant action on the IAS. It reduces myogenic tone and contractile responses of this tissue to sympathetic nerve stimulation. Further studies are required to clarify its mechanism of action more precisely.

Topical nitrates potentiate the effect of botulinum toxin in the treatment of patients with refractory anal fissure

BACKGROUNDAnal fissure is perpetuated by high sphincter pressures and secondary local ischaemia. Pharmacological approaches include topical nitrates and botulinum toxin (BT) which act to reduce anal pressure. BT lowers anal...

A randomised, prospective, double-blind, placebo-controlled trial of glyceryl trinitrate ointment in treatment of anal fissure

Anal fissure is most commonly treated surgically by internal anal sphincterotomy. However, there is some concern over the effects of this procedure on continence. Nitric oxide donors such as glyceryl trinitrate (GTN) have been shown to cause a reversible chemical sphincterotomy capable of healing fissures in a small series of cases. This study reports a prospective, randomised, double-blind, placebo-controlled trial to test the hypothesis that topical GTN is the best first-line treatment for chronic anal fissure. 80 consecutive patients were randomised to receive treatments with topical 0.2% GTN ointment or placebo. Maximum anal resting pressure (MARP) was measured with a constantly perfused side-hole catheter before and after the first application of trial ointment. Anodermal blood flow was measured during manometry by laser Doppler flowmetry. After initial treatments, patients were given a supply of ointment (either GTN or placebo) to be applied to the lower anal canal twice daily. Patients were reviewed 2-weekly. At the initial and follow up visits patients were asked to record pain experienced on defaecation on a linear analogue pain score. Endpoints were healing of the fissure or condition after 8 weeks of treatment. After 8 weeks, healing was observed in 26/38 (68%) patients treated with GTN and in 3/39 (8%) patients treated with placebo (p < 0.0001, chi 2 test). Linear analogue pain score fell significantly in both groups after 2 weeks of treatment. This fall was maintained in those treated with GTN but pain scores returned to pre-treatment values by 4 weeks on treatment with placebo. MARP fell significantly from a mean of 115.9 (SD 31.6) to 75.9 (30.1) cm H2O (p < 0.001, Student's paired t-test) in patients treated with GTN but no change was seen in MARP after placebo. Anodermal blood flow measured by laser Doppler flowmetry significantly increased after application of GTN ointment but was unaffected by placebo. Topical GTN provides rapid, sustained relief of pain in patients with anal fissure. Over two-thirds of patients treated in this way avoided surgery which would otherwise have been required for healing. Long-term follow up is needed to assess the risk of recurrent fissure in patients with GTN.

Ultra slow wave pressure variations in the anal canal before and after lateral internal sphincterotomy.

Ultra slow waves (USW's) in the anal canal are discrete pressure fluctuations with a low frequency (1-2/minute) and high amplitude (> or = 10% above or below baseline resting pressure). To investigate the nature of these USW's, anorectal manometry was performed in 20 control subjects as well as in 58 patients presenting with anal fissure or symptomatic hemorrhoids, before and 2 weeks after lateral internal sphincterotomy. USW's could be demonstrated in two control subjects and in 29 patients. The median value of maximum anal resting pressure (MARP) in the two control subjects with USW's was significantly higher than the median MARP in the 18 control subjects without USW's (181.5 vs. 92 cm H2O, p < 0.001, two-tailed Mann-Whitney test). The same difference was found between MARP in patients with and without USW's (158 vs. 138 cm H2O, p < 0.05, two-tailed Mann-Whitney test). All patients were treated by means of lateral internal sphincterotomy (LIS). Two weeks after this procedure USW's had disappeared in half of the patients. The MARP in these patients was reduced to a level found in control subjects without USW's. This pressure reduction was significantly greater than in patients with persistent USW's (40% vs. 15%, p < 0.02, two-tailed Mann-Whitney test). Because USW's are associated with high MARP and disappear when such a high anal canal resting pressure is reduced by LIS to a level found in control subjects without USW's, it can be concluded that USW's are the manifestation of increased activity of the internal anal sphincter.