Sacral Nerve Stimulation for Fecal Incontinence: External Anal Sphincter Defect <Emphasis Type="Italic">vs</Emphasis>. Intact Anal Sphincter

Purpose  This prospective study was designed to assess the effectiveness of sacral nerve stimulation for fecal incontinence in patients with external anal sphincter defect and to evaluate its efficacy regarding presence and size of sphincter defect. Methods  Fifty-three consecutive patients who underwent sacral nerve stimulation for fecal incontinence were divided into two groups: external anal sphincter defect group (n = 21) vs. intact sphincter group (n = 32). Follow-up was performed at 3, 6, and 12 months with anorectal physiology, Wexner’s score, bowel diary, and quality of life questionnaires. Results  The external anal sphincter defect group (defect <90°:defect 90°–120° = 11:10) and intact sphincter group were comparable with regard to age (mean, 63 vs. 63.6) and sex. Incidence of internal anal sphincter defect and pudendal neuropathy was similar. All 53 patients benefited from sacral nerve stimulation. Weekly incontinent episodes decreased from 13.8 to 5 (P < 0.0001) for patients with external anal sphincter defects and from 6.7 to 2 (P = 0.001) for patients with intact sphincter at 12-month follow-up. Quality of life scores improved in both groups (P < 0.0125). There was no significant difference in improvement in functional outcomes after sacral nerve stimulation between patients with or without external anal sphincter defects. Clinical benefit of sacral nerve stimulation was similar among patients with external anal sphincter defects, irrespective of its size. Presence of pudendal neuropathy did not affect outcome of neurostimulation. Conclusions  Sacral nerve stimulation for fecal incontinence is as effective in patients with external anal sphincter defects as those with intact sphincter and the result is similar for defect size up to 120° of circumference. ^†Deceased.     

Treatment of Experimental Injury of Anal Sphincters with Primary Surgical Repair and Injection of Bone Marrow-Derived Mesenchymal Stem Cells

Purpose Sphincter injury is a common cause of anal incontinence. Surgical repair remains the operation of choice; however, the outcome often is poor. We investigated the ability of injected bone marrow-derived mesenchymal stem cells to enhance sphincter healing after injury and primary repair in a preclinical model. Methods Twenty-four inbred Wistar Furth rats were divided into three groups. As a control, Group A underwent sham operation. Group B had sphincterotomy and repair of both anal sphincters plus saline injections. The study group (Group C) underwent sphincterotomy and repair followed by intrasphincteric injections of syngenic bone marrow-derived mesenchymal stem cells. A further group (Group D) of outbred Wistar rats treated with mesenchymal stem cells and immunosuppressive therapy also was evaluated. At 30 days, histologic and morphometric analysis and in vitro contractility testing was performed. Results A significant decrease of muscle tissue was observed at the site of repair after sphincter injury. However, in Groups C and D, histologic examination demonstrated new muscle fibers and morphometric analysis revealed a significantly greater muscle area fraction than in Group B (P < 0.05). Moreover, mesenchymal stem cells injection improved contractility of sphincters strips compared with Group B (P < 0.05). No significant differences were found between Groups C and D. Conclusions In our experimental model, bone marrow-derived mesenchymal stem cells injection improved muscle regeneration and increased contractile function of anal sphincters after injury and repair. Therefore, mesenchymal stem cells may represent an attractive tool for treating anal sphincter lesions in humans. Investigations into the biologic basis of this phenomenon should increase our knowledge on underlying mechanisms involved in sphincter repair. Supported by a grant from the University of Siena (PAR 2005). Address of correspondence: Marco Lorenzi, M.D., Department of Surgery, University of Siena, Viale Bracci, 53100 Siena, Italy.     

Diagnostic precision of endoanal MRI in the detection of anal sphincter pathology—a meta-analysis

Objective This study aims to evaluate the diagnostic precision of endoanal magnetic resonance imaging in identifying anal sphincter injury and/or atrophy when compared with either endoanal ultrasound or surgical diagnosis. Materials and methods Quantitative meta-analysis was performed on nine studies, comparing endoanal MRI with endoanal ultrasound or surgical diagnosis in 157 patients. Sensitivity, specificity, and diagnostic odds ratio were calculated for each study. Summary receiver operating characteristic curves (SROC) and subgroup analysis were undertaken. Results The overall sensitivity and specificity of endoanal MRI for external sphincter injury was 0.78 (95%CI: 0.66–0.84) and 0.66 (95%CI: 0.51–0.79), respectively. For internal sphincter injury detection, this was 0.63 (95%CI: 0.50–0.74) and 0.71 (95%CI: 0.60–0.81), respectively. For detection of atrophy, this was 0.86 (95%CI: 0.71–0.95) and 0.82 (95%CI: 0.65–0.93), respectively. The area under the SROC curve and diagnostic odds ratio were 0.84 (SE = 0.07) and 6.14 (95%CI: 2.17–17.4) for external sphincter injury, 0.79 (SE = 0.07) and 4.60 (95%CI: 1.75–12.15) for internal sphincter injury, and 0.92 (SE = 0.08) and 21.49 (95%CI: 2.87–160.64) for sphincter atrophy. Conclusion Endoanal MRI was sensitive and specific for the detection of external sphincter injury and especially sphincter atrophy. It may be useful as an alternative to endoanal ultrasound in patients presenting with fecal incontinence, although further clinical studies are needed to identify its best application in clinical practice.     

Sacral Nerve Stimulation for Fecal Incontinence Related to Obstetric Anal Sphincter Damage

Purpose Sphincter repair is the standard treatment for fecal incontinence secondary to obstetric external anal sphincter damage; however, the results of this treatment deteriorate over time. Sacral nerve stimulation has become an established therapy for fecal incontinence in patients with intact sphincter muscles. This study investigated its efficacy as a treatment for patients with obstetric-related incontinence. Methods Fecally incontinent patients with external sphincter defects who would normally have undergone overlapping sphincter repair as a primary or repeat procedure were included. Eight consecutive women (median age, 46 (range, 35–67) years) completed temporary screening; all eventually had permanent implantation. Results Six of eight patients had improved continence at median follow-up of 26.5 (range, 6–40) months. Fecal incontinent episodes improved from 5.5 (range, 4.5–18) to 1.5 (range, 0–5.5) episodes per week (P = 0.0078). Urgency improved in five patients, with ability to defer defecation improving from a median of <1 (range, 0–5) minute to 1 to 5 (range, 1 to >15) minutes (P = 0.031, all 8 patients). There was no change in anal manometry or rectal sensation. There was significant improvement in lifestyle, coping/behavior, depression/self-perception, and embarrassment as measured by the American Society of Colon and Rectal Surgery fecal incontinence quality of life score. Conclusions Sacral nerve stimulation is potentially a safe and effective minimally invasive treatment for fecal incontinence in patients with de novo external anal sphincter defects or defects after unsuccessful previous external anal sphincter repair, although numbers remain small. Dr. Michael Kamm is a consultant to and received research support from Medtronic, however, study design, performance, analysis, and reporting have been conducted without the influence of Medtronic.     

Effect of Second Vaginal Delivery on Anal Function in Patients at Risk of Occult Anal Sphincter Injury after First Forceps Delivery

Purpose  The study was designed to determine the effect of further vaginal delivery on anal sphincter function in women after apparently uncomplicated primiparous forceps delivery. Methods  Fifty-two secundigravid women whose first child was forceps-assisted were compared with a control group of 20 women who had undergone spontaneous first vaginal delivery. Both groups were studied antenatally and again at 12 weeks after second delivery using a standardized bowel function questionnaire, endoanal ultrasound, and anal manometry. The primary outcome was fecal incontinence score after second delivery. Results  Before second delivery, 20 of 52 (39 percent) of the forceps group and 3 of 20 (15 percent) control subjects (P = 0.103) reported minor alteration in fecal incontinence. Endoanal ultrasound was more frequently abnormal (38/52 (73 percent) vs. 6/20 (30 percent); P = 0.002), and median anal canal squeeze (71 vs. 104 mmHg; P = 0.004) and resting pressures (43 vs. 58 mmHg; P = 0.004) were lower in the forceps group. There was no difference in continence score between first and second delivery for the forceps group (P = 0.19) group or control subjects (P = 0.18). However, 10 of 38 (26 percent) women with an abnormal endoanal ultrasound after first forceps delivery developed new or worsening symptoms after second delivery. Conclusions  One-quarter of women with occult anal sphincter injury after first forceps delivery experienced some minor alteration in fecal continence after the second delivery. Presented at the 23^rd annual meeting of the Society for Maternal Fetal Medicine, San Francisco, California. Supported by the Irish Health Research Board.     

Effects of Caffeine on Anorectal Manometric Findings

Purpose  This study was designed to evaluate the effects of caffeine on anorectal function by anorectal manometry. Methods  Ten healthy subjects were studied. They drank 200 ml of water and later 200 ml of a solution that contained caffeine 3.5 mg/kg body weight. The anorectal manometric study was divided into three periods: basal, water, and caffeine; each period lasted 45 minutes. Results  After the ingestion of water, the basal anal sphincter pressure showed no change during the 45-minute recording, whereas after caffeine consumption the basal anal sphincter pressure increased at 10 minutes (P = 0.047) and 15 minutes (P = 0.037). The average basal anal sphincter pressure throughout the 45 minutes was significantly higher after caffeine ingestion than after water (P = 0.013). After caffeine intake, the maximum squeeze pressure increased significantly (P = 0.017) compared with the basal period. Both water and caffeine consumption caused a decrease in the rectal sensory threshold for the desire to defecate. Conclusions  Caffeine 3.5 mg/kg body weight in 200 ml of water resulted in stronger anal sphincter contractions both at basal period and during voluntary squeeze. The sensory threshold was also decreased, leading to an earlier desire to defecate. Caffeine consumption may result in an earlier desire to defecate, leading to defecation if the anal sphincter can relax voluntarily.     

Closure Mechanism of the Anal Canal in Women: Assessed by Three-Dimensional Ultrasound Imaging

Purpose  To describe the functional correlates of anal canal anatomy using 3 dimensional ultrasound imaging. Methods  Ten nulliparous women were studied by using a 10-cm bag of 20-mm diameter. The bag was placed along the anal canal and inflated with 20 to 45 ml water, in 5-ml increments. At each volume, a three-dimensional ultrasound volume of the anal canal was obtained while the subjects were at rest and squeeze. The ultrasound images were analyzed to determine the relationship between the bag cross-sectional area and bag pressure. Results  At low distension volumes, the bag is shaped like an “hourglass.” The flared ends of the funnels correspond with the proximal and distal margins of the puborectalis muscle and external anal sphincter respectively. With increasing bag volumes, the length of completely closed segment of anal canal decreased. The last anal segment to open at rest was the one surrounded by all three structures. Anal contraction resulted in reduction of the anal canal cross-sectional area; the least compliant part of the anal canal was the one surrounded by external anal sphincter. Conclusion  The internal anal sphincter, external anal sphincter, and puborectalis muscle are all involved in the anal canal closure function. During contraction, the external anal sphincter is the strongest component of anal canal closure mechanism. Supported by an NIH grant-RO-1, grant DK60733.     

A novel magnetic device to prevent fecal incontinence (preliminary study)

Background and aims In this research we propose an original magnetic device to strengthen the hypo-atonic anal sphincter and prevent fecal incontinence. Methods The device consists in a couple of small magnetic plaques to be surgically inserted in the wall of the anal canal between the external and internal anal sphincters with the opposite polarities face to face, so that, attracting themselves, close the anal lumen. Three couples of magnets made of materials of different magnetic force (neodymium > ferrite > plastoferrite) were evaluated in each of three swine anatomical preparations by measuring the endoanal pressure with a manometric catheter, both before and after magnet implantation. The mean pressures obtained before and after magnet insertion were statistically compared with Student t test. Results The endoanal pressure after the insertion of neodymium magnets was 79.7 ± 13.1 (mean ± SD), after ferrite magnets was 42.1 ± 5.6 mmHg and after plastoferrite magnets was 21.6 ± 4.6 mmHg, all of them significantly higher than the pressure recorded in basal conditions (1.72 ± 0.71 mmHg). Conclusion This research demonstrated that the implantation of a couple of magnets in the wall of the anal canal is able to create a high pressure zone of a value sufficient to prevent fecal incontinence and that the strength of this “dynamic closure” can be modulated by using magnets of various attraction force, so allowing a “tailored correction” of the anal sphincter hypotension.     

Muscle change after anal sphincter reinnervation by a normal somatic peripheral nerve

INTRODUCTION: Pudendal neuropathy causes idiopathic fecal incontinence. We thus designed a new operation for idiopathic fecal incontinence based on the hypothesis that a conversion from innervation by the neuropathic pudendal nerve to that by the normal somatic peripheral nerve innervating a larger skeletal muscle might enable the anal sphincter to recover from neuropathic muscular atrophy. This study was undertaken to investigate the muscular change of the external anal sphincter after such an operation. METHODS: On 14 sides of eight dogs, the transected proximal end of the nerve innervating the biceps femoris muscle was microsurgically cross-transferred to the distal end of the transected pudendal nerve. The external anal sphincter was analyzed by electromyography and adenosine 5'-triphosphatase staining at three months after surgery. RESULTS: On 13 of 14 sides, the external anal sphincter was well preserved and the evoked potential was clearly recorded. The external anal sphincter in these dogs, however, had neither any basal electrical activity nor any increased electrical activity. The percentage of Type 1 muscle fibers of the external anal sphincter innervated by the nerve to the biceps femoris muscle (30.9 +/- 9.8 percent) was significantly higher than that of the normal external anal sphincter (15.2 +/- 8.5 percent; P < 0.001) and also significantly lower than that of the normal biceps femoris muscle (38.5 +/- 7.5 percent; P = 0.006). The diameter of the muscle fibers (Types 1 and 2) of the external anal sphincter (expressed as mean +/- standard deviation) innervated by the nerve to the biceps femoris muscle (32.9 +/- 6.2 microm) was also significantly larger than that of the normal external anal sphincter (29.9 +/- 5.1 microm; P = 0.021) and significantly smaller than that of the normal biceps femoris muscle (36.1 +/- 6.1 microm; P = 0.028). CONCLUSIONS: The cross-nerve transfer procedure in a dog model was found to prevent muscular atrophy of the external anal sphincter when performed immediately after pudendal nerve transection.     

Prognostic Value of Endoanal Ultrasound for Fistula-in-Ano: A Retrospective Analysis

Abstract Purpose  This study was designed to assess whether preoperative endoanal ultrasound plays a prognostic role in the surgical outcome of anal fistula. Methods  A retrospective review was conducted at a single institution. Results  Sixty-nine patients underwent 83 studies. Indications for endoanal ultrasound included complex fistulas and tracts, multiple external openings, recurrent fistulas, and/or failed previous surgical intervention. Mean age was 51.7 years. Fifty-three patients (77 percent) were men. Mean duration of symptoms was 3.1 years. Forty-nine patients (71 percent) had undergone previous surgical intervention to eradicate sepsis or fistula. Sixty patients (87 percent) underwent surgical interventions and were divided into two groups: Group A (73.3 percent), concordance with ultrasound findings; and Group B (26.7 percent), nonconcordance. Mean follow-up in the surgical group was 15.6 months. Measured outcome was total number of operations per patient and failure rate of primary surgical intervention. No difference was noted in mean total number of operations between Group A (1.57) and Group B (1.69) (P = 0.71). There was a statistically nonsignificant trend toward a higher failure rate of the primary intervention in the nonconcordance group [failure rate 18.2 percent in Group A vs. 25 percent in Group B (P = 0.72)]. Conclusions  The findings and accuracy of preoperative endoanal ultrasound did not influence postoperative outcome. Reprints are not available. Read at the meeting of The American Society of Colon and Rectal Surgeons, St. Louis, Missouri, June 2 to 6, 2007     

Risk factors in childbirth causing damage to the pelvic floor innervation

The innervation of the pelvic floor musculature is damaged in both stress urinary incontinence and idiopathic (neurogenic) anorectal incontinence. Because childbirth has been considered to be a causative factor in stress incontinence we have assessed the effect of childbirth on the innervation of the pelvic floor musculature in 122 consecutively referred women. They were investigated 48–72 h and 2 months after delivery; 51 were also studied 6 months prior to delivery. In 45 of these 51 women delivered vaginally, EMG studies of the external anal sphincter muscle showed that the fibre density (FD) increased from 1.38±0.14 before delivery to 1.57±0.19 2 months after delivery (p<0.01). There was no change in the FD in the external anal sphincter muscle after delivery in 20 women delivered by Caesarean section. The pudendal nerve terminal motor latency (PNTML) measured 48–72 h after delivery was increased in the 102 women delivered vaginally compared to 34 nulliparous control subjects. Analysis of the whole group of 122 women showed that multiparity, forceps delivery, increased duration of the second stage of labour, third degree perineal tear and high birth weight were important factors leading to pudendal nerve damage. Epidural anaesthesia had no effect on pudendal nerve function. Modification of these obstetric risk factors may ultimately reduce the frequency of stress urinary and faecal incontinence in women.     

Delayed pudendal nerve conduction and endosonographic appearance of the anal sphincter complex

PURPOSE: The aim of this study was to test the hypothesis that a delay in pudendal nerve conduction as measured by pudendal nerve terminal motor latency should be associated with atrophy of the external anal sphincter as measured using endoanal ultrasound. METHODS: Sixty-two adult females (median age, 58.9 (range, 22–88) years) presenting for evaluation of fecal incontinence with no evidence of an external anal sphincter tear on ultrasound were recruited. Ultrasound was performed with a 7.5-MHz radial rotating axial endoprobe in the left lateral position. Four measurements were made in the transverse plane—the external anal sphincter thickness in the midanal canal at the 6 o'clock and 9 o'clock positions, the internal sphincter at the 9 o'clock position, and the external anal sphincter in the low canal at the 9 o'clock position. Pudendal nerve terminal motor latency was measured using a transrectal nerve stimulation technique with measurement of the evoked muscle response. RESULTS: Although there was a trend toward thinner external sphincter muscles in those with bilateral prolonged pudendal nerve terminal motor latency, independent sample t-tests and Pearson correlation coefficients showed no statistically significant relationship (right pudendal nerve terminal motor latency:P=0.083, 0.184, 0.128, 0.910;r=0.228, 0.175, –0.201, –0.015; left pudendal nerve terminal motor latency:P=0.946, 0.276, 0.510, 0.123;r=–0.009, –0.143, –0.087, –0.201). CONCLUSIONS: No statistically significant relationship between ultrasound-measured anal sphincter muscle thickness and pudendal nerve terminal motor latency was identified. Although a trend was suggested that could be further evaluated by a study with a larger sample size and a control group with asymptomatic patients, the small differences in muscle thickness involved and the difficulties in measurement suggest that the establishment of clinically useful ultrasound criteria for the detection of the neuropathic anal sphincter complex is unlikely.     

Overlap Technique Improves Results of Primary Surgery after Obstetric Anal Sphincter Tear

Purpose This study was designed to evaluate prospectively the results of the overlap technique in primary sphincter reconstruction after obstetric tear. Methods Obstetric tears in 44 women were operated on with primary overlap reconstruction. These women were investigated six to nine months after the operation. Results were compared with those of a historical control group of 52 women whose obstetric sphincter rupture had been treated with the end-to-end technique. Results The overlap group had significantly more incontinence symptoms after delivery and repair of the sphincter tear than before delivery (P < 0.0001); however, their incontinence symptoms were significantly fewer than those of the end-to-end group (P = 0.004). The prevalence of persistent rupture of the external anal sphincter was significantly lower in the overlap group (6/44, 13.6 percent) than in the end-to-end group (39/52, 75 percent; P < 0.0001). Internal anal sphincter rupture occurred in 5 patients (11.4 percent) in the overlap group and in 40 patients (76.9 percent) in the end-to-end group (P < 0.0001). Conclusions The overlap technique should be adopted as the method of choice for primary sphincter repair after obstetric tear.     

Endosonographic Imaging of Anal Sphincter Injury

PURPOSE: This study was designed to test the hypothesis that the extent of anal sphincter muscle injury as graded at endosonography correlates with the degree of functional impairment. METHODS: Three hundred and thirty adults presenting for evaluation of fecal incontinence were recruited. Ultrasound was performed with a 7.5-MHz radial rotating axial endoprobe in the left lateral position. Anal sphincter muscle tears were graded on the basis of the degree of circumferential involvement (< or >25 percent) and by an assessment of the superoinferior longitudinal extent of an external anal sphincter tear. Muscles that demonstrated multiple tears, poor visualization, or fragmentation were classed as fragmented. Sphincter injuries were correlated with basal and squeeze pressures at manometry, pudendal nerve terminal latencies, and the severity of symptoms using the Parks-Browning clinical score. RESULTS: Patients with an intact external anal sphincter had a higher squeeze pressure (mean, 162.6 cm H(2)O) than those with a partial- (mean, 125.7 cm H(2)O) or full-length tear (mean, 124.9 cm H(2)O; P < 0.0001). There was no significant difference in squeeze pressure between those with partial- vs. full-length external anal sphincter tears nor between circumference tears < or >25 percent. Basal pressure was significantly lower in those with a full-length external anal sphincter tear (47.8 cm H(2)O) vs. an intact external anal sphincter (65.7 cm H(2)O; P < 0.001). The basal pressure in those with an intact internal anal sphincter was not significantly different from those with clearly defined internal anal sphincter tears, and the degree of circumferential involvement was also not important in this regard. However, those with a fragmented internal anal sphincter had a significantly lower basal pressure than other subgroups of internal anal sphincter injuries (P < 0.001). There was no association between external or internal anal sphincter status and the mean pudendal nerve terminal motor latency, suggesting the patient groups were neurologically similar. There was no significant association between external or internal anal sphincter status and the severity of reported symptoms. CONCLUSION: Correlations between the presence or absence of muscle tears and reduced manometric function have been identified. Further grading of tears was of less importance. No relationship between muscle injuries and the severity of clinical symptoms could be elicited.     

Pelvic Nerve Stimulation Evokes Nitric Oxide Mediated Distal Rectal Relaxation in Pigs

Purpose  Pelvic nerve stimulation evokes a complex motility response in the pig rectum with a proximal decrease and a distal increase in cross-sectional area. This study investigated whether the distal increase in the cross-sectional area is because of smooth muscle relaxation mediated by nitric oxide. Methods  The pelvic nerves were stimulated with cuff electrodes in ten chloralose-anesthetized minipigs. Pressure, volume, and cross-sectional areas at five positions in the rectum were obtained during stimulation to examine the effect of N^G-nitro-L-arginine (an inhibitor of nitric oxide synthase) injection. Results  Stimulation evoked a median pressure decrease of 13 cm H₂O (range, 0–27; P < 0.05; n = 10) in the anal canal, a pressure increase of 6 cm H₂O (range,-15 to 30; P < 0.05; n = 10) in the rectum and a decrease of 39 mL (range, 30–63; P < 0.05; n = 6) in rectal volume. Rectal cross-sectional areas decreased 33 percent (range, 5–56; P < 0.02; n = 7) in the proximal part and increased 32 percent (range, 9–67; P < 0.02; n = 8) in the distal part. N^G-nitro-L-arginine eliminated the increase in the distal rectal cross-sectional area (n = 5) and the decrease in anal canal pressure (n = 9) in all tested animals. Conclusion  Pelvic nerve stimulation evokes distal rectal relaxation in pigs, sensitive to N^G-nitro-L-arginine, which suggests that this smooth muscle response is mediated by nitric oxide. This work was supported by grants from the Institute of Experimental Clinical Research, Aarhus University Hospital, Aarhus, Denmark Reprints are not available.     

Effect of neoadjuvant chemoradiation on postoperative fecal continence and anal sphincter function in rectal cancer patients

Background and aims Neoadjuvant chemoradiation (nCRT) followed by curative surgery has gained acceptance as the therapy of choice in locally advanced rectal cancer. This prospective study evaluates the effect of nCRT on postoperative anorectal function and continence. Patients and methods Group A consisted of 12 patients (59.8 ± 11.9 years, male:female = 8:4) who received nCRT (5-FU, CPT-11. 45 + 5.4 Gy boost) before surgery and Group B of 27 patients (61.9 ± 10.6 years, male:female = 16:11) who were treated by surgery alone. All patients received a questionnaire to evaluate stool continence and anorectal function before as well as after surgery. Anorectal function was further analyzed by perfusion manometry pre- and postoperatively. Results Preoperatively, none of the patients had signs or symptoms of fecal incontinence, and preoperative measurements showed values within normal limits. Postoperatively, fecal continence was impaired in both groups, but no significant difference was found between patients with or without nCRT. Anorectal manometry revealed an impairment of anorectal function after low anterior resection regardless of the treatment regime. Conclusion nCRT does not impair anorectal function and fecal continence. The deterioration of continence and anal sphincter function after sphincter preserving surgery is solely caused by the surgical procedure.     

Continence disorders after anal surgery—a relevant problem?

Subject  Anal incontinence is a well-known and feared complication following surgery involving the anal sphincter, particularly if partial transection of the sphincter is part of the surgical procedure. Methods  The literature was reviewed to evaluate the risk of postoperative incontinence following anal dilatation, lateral sphincterotomy, surgery for haemorrhoidal disease and anal fistula. Results  Various degrees of anal incontinence are reported with frequencies as follows: anal dilatation 0–50%, lateral sphincterotomy 0–45%, haemorrhoidal surgery 0–28%, lay open technique of anal fistula 0–64% and plastic repair of fistula 0–43%. Results vary considerably depending on what definition of “incontinence” was applied. The most important risk factors for postoperative incontinence are female sex, advanced age, previous anorectal interventions, childbirth and type of anal surgery (sphincter division). Sphincter lesions have been reported following procedures as minimal as exploration of the anal canal via speculum. Conclusions  Continence disorders after anal surgery are not uncommon and the result of the additive effect of various factors. Certain risk factors should be considered before choosing the operative procedure. Since options for surgical repair of postoperative incontinence disorders are limited, careful indications and minimal trauma to the anal sphincter are mandatory in anal surgery.     

Age Effects on Internal Anal Sphincter Thickness and Diameter in Nulliparous Females

Purpose Age can affect the delicate physiologic balance of the internal anal sphincter diameters and pressure governed by Laplace’s law. This study compares the effect of aging on the internal anal sphincter thickness and diameter in younger and older nulliparous females without symptoms of fecal incontinence undisturbed by an endoanal probe. Methods Magnetic resonance images were selected from a large database of nulliparous females to form two groups: “younger” females, aged 30 years and younger (n = 32), and “older” females, aged 50 years and older (n = 32). All patients were scanned without endoanal coils to allow undistorted measurement of the internal anal sphincter diameters. Inner and outer diameters were measured from axial magnetic resonance images and used to calculate sphincter thickness and mean radius by two independent investigators blinded to patient age. Results The mean age in the younger group was 26 ± 2.8 years, whereas that of the older group was 61.8 ± 7.6 years. Older females had a 33 percent thicker internal anal sphincter (younger vs. older: 4.5 ± 0.7 vs. 5.9 ± 1 mm; P < 0.001), a 20 percent larger inner diameter (7.1 ± 1.3 vs. 8.5 ± 1.8 mm; P = 0.001), and a 27 percent larger outer diameter (16 ± 2.1 vs. 20.3 ± 3.3 mm; P < 0.001) than younger females. Neither sphincter thickness nor inner or outer diameter correlated with body mass index. Conclusions There is an increase in internal anal sphincter thickness, inner diameter, and outer diameter, which correlates with age in asymptomatic nulliparous females. Supported by the National Institutes of Health, ORWH & NICHD Sex & Gender Factors Affecting Women’s Health SCOR: P50, and NICHD R01 HD 044406: NICHD R01 DK 051405, R01 HD 038665; German Research Foundation (DFG, HU1502/1–1). Presented as a poster at the annual meeting of the American Urogynecologic Society, October 19 to 21, 2006, Palm Springs, Florida. Presented as an oral poster at the annual meeting of the International Urogynecological Association, September 6 to 9, 2006, Athens, Greece. Presented as an oral poster and oral presentation at the annual meeting of the German Association of Gynecology and Obstetrics, September 19 to 22, 2006, Berlin, Germany.     

Clinical outcome of anterior overlapping external anal sphincter repair with internal anal sphincter imbrication

Fecal incontinence caused by overt anterior sphincter defects sustained during childbirth is usually treated by a delayed overlapping repair of the external anal sphincter. However, an obstetric trauma is frequently associated with disruption of the perineal body and loss of the distal rectovaginal septum. Data regarding a combined repair, consisting of restoration of the rectovaginal septum and perineal body, overlapping external anal sphincter repair, and imbrication of the internal anal sphincter, are scanty. PURPOSE: This prospective study was aimed at the following: 1) evaluating the clinical outcome of such an anterior anal repair in patients with fecal incontinence caused by obstetric trauma; 2) comparing the functional results with those obtained in a historical group of patients who underwent a conventional direct sphincter repair. METHODS: During the period between 1973 and 1989, 24 female patients (median age, 44 (range, 28–67) years) with fecal incontinence underwent direct sphincter repair (Group I). During the period between 1989 and 1994, a consecutive series of 31 female patients (median age, 46 (range, 23–78) years) with fecal incontinence underwent anterior anal repair (Group II). RESULTS: At two years of follow-up, continence had been restored in 15 patients (63 percent) in Group I, whereas restoration of continence was successful in 21 patients (68 percent) in Group II. CONCLUSION: The more complex anterior anal repair fails to confer clinical benefit compared with the rather simple direct sphincter repair.Read at the meeting of The American Society of Colon and Rectal Surgeons, Montreal, Quebec, Canada, May 7 to 12, 1995.     

Effect of delivery on anal sphincter morphology and function

PURPOSE: Anal sphincter injury is a serious complication of childbirth, which may result in persistent anal incontinence. Occult injuries, visualized with endoanal ultrasonography, have previously been reported in up to 35 percent of females in a British study. The aim of the present study was to study anal sphincter morphology and function before and after delivery in primiparous females in the United States. METHODS: Thirty-eight primiparous patients (mean age, 31 years) were evaluated with endoanal ultrasonography, anal manometry, and pudendal nerve terminal motor latency during pregnancy and after delivery. Bowel function before and after delivery was recorded according to set questionnaires. Cesarean section was performed in three patients. RESULTS: Clinical sphincter tears, requiring primary repair, occurred in 15 percent of the patients. After delivery endoanal ultrasonography revealed disruptions in the external anal sphincter in six patients, but no patient had disruption in the internal anal sphincter. One patient had slight scarring in the external sphincter. Of the seven patients with pathologic findings at endoanal ultrasonography, the left pudendal latency increased after delivery (P<0.05), and manometric results were reduced. Three of these seven patients had a third-degree or fourth-degree tear during delivery. All investigations were normal in the three patients who underwent cesarean section. CONCLUSIONS: The present study demonstrates a significant frequency of sphincter injuries (20 percent) after vaginal delivery. Obstetricians should be aware of this risk and explicitly inquire about incontinence symptoms at follow-up after delivery.Health East Foundation and Mead Johnson Pharmaceutical Inc. provided economic support, enabling participating volunteers to receive a stipend and baby supplies on completion of their tests.Dr. Mellgren was supported by grants from Health East Foundation and Karolinska Institutet Research Funds. Dr. Zetterström was supported by grants from Karolinska Institutet Research Funds.Read at the meeting of The American Society of Colon and Rectal Surgeons, San Antonio, Texas, May 2 to 7, 1998. Poster presentation at the XVIIth Biennial Congress of the International Society Of University Colon and Rectal Surgeons, Malmö, Sweden, June 7 to 11, 1998.