Ahmed Shafik

A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation

A study, comprising dissection and microscopic examination of the pectinate area with special consideration to anal glands, was performed in 29 cadavers varying from fully mature neonatal deaths to 52 years of age. At the junction of the anal canal proper with the rectal neck, an “anorectal sinus” (a submucosal anal circumferential depression) was identified in 18 specimens; in 6 specimens, the anorectal sinus was replaced by a fibroepithelial band (“anorectal band”); in 5 specimens, the anorectal sinus was absent, and in 3 of the 5 specimens only scattered epithelial cells (“epithelial debris” of the anorectal sinus) were detected. These findings suggest that the anorectal sinus is an embryonic vestige which results from hindgut “invagination” by the proctodeum. Its persistence or partial obliteration would result in the formation of tubular structures which are considered by investigators as anal glands. The sinus may be completely obliterated or may leave behind a submucosal “anorectal band” or scattered “epithelial debris”. Evidence in favor of this new concept is put forward. The role of anorectal sinus, anorectal band, and epithelial debris in the genesis of some idiopathic anal lesions is discussed.

Pudendal canal syndrome as a cause of vulvodynia and its treatment by pudendal nerve decompression.

Notwithstanding many established causes of vulvodynia there still remains an idiopathic group with unknown etiology and variable results of treatment. We present 11 women with idiopathic vulvodynia in whom the etiology could be defined and who were successfully treated. Age varied from 28-53 years. The vulvar pain was associated with stress urinary incontinence in 6/11 patients and all had constipation. Perineal and vulvar hypoesthesia occurred in 6, weak anal reflex in 7 and diminished EMG activity of the external anal sphincter in 3, of the external urethral sphincter in 6 and of the levator ani muscle in 11. There was significant increase (P<0.05) of the pudendal nerve terminal motor latency (PNTML) in all. The motor and sensory change as well as the increased PNTML point to pudendal canal syndrome. Pudendal nerve block, as a diagnostic and therapeutic test, effected temporary pain relief. Pudendal nerve decompression was performed. The inferior rectal nerve was exposed through a para-anal incision, and followed to the pudendal nerve in the pudendal canal. Pudendal canal fasciotomy was done to release the pudendal nerve in the ischiorectal fossa. Vulvar pain disappeared in 9/11 women and stress urinary incontinence in 4/6. Anal reflex was normalized in 5/7 women, and vulvar and perineal hypoesthesia in 4/6. The EMG activity of the external urethral sphincter improved in 4/6, of the external anal sphincter in 2/3 and of the levator ani in 9/11 women. The PNTML was normalized in 9/11 women. In conclusion, pudendal nerve decompression effected relief and improvement in the sensory and motor manifestations of the pudendal nerve in 9/11 women. Two women did not improve due probably to an irreversible damage of the pudendal nerve, or to incomplete pudendal nerve decompression.

Venous Tension Patterns in Cord Veins. I. In Normal and Varicocele Individuals

A study on venous tension patterns in the cord veins was done on 30 normal individuals and 32 patients with a left varicocele. Semen analyses and testicular biopsies were done. Venous tension was measured with the patient at rest and during Valsalvs maneuver with a saline manometer. The average normal venous tension with the patient at rest was 58.7 mm. Hg on the right side and 59.9 mm. Hg on the left side. In varicocele patients venous tension on the right side was slightly higher than normal (the average difference being 0.9 mm. Hg), whereas on the left side it was considerably higher (the average difference being 19.7 mm. Hg with the patient at rest and 22 mm. Hg during Valsalvas maneuver). The average increase of venous tension in varicose veins during demonstrates conclusively the presence of venous reflux and hypertension in patients with varicocele. The possible effects of venous reflux on cord veins and testes are presented. The role of venous hypertension in the bilateral effect of varicocele is discussed.

A STUDY OF THE CONTINENCE MECHANISM OF THE EXTERNAL URETHRAL SPHINCTER WITH IDENTIFICATION OF THE VOLUNTARY URINARY INHIBITION REFLEX

PURPOSE The role of the external urethral sphincter in the opposition and interruption of the act of voiding was investigated. MATERIALS AND METHODS The study included 7 men and 5 women with a mean age plus or minus standard deviation of 38.6 +/- 11.2 years. The bladder was filled with saline up to the urge sensation. Detrusor and posterior urethral pressures were recorded before and upon resisting the reflex detrusor contraction, and upon interrupting voiding by voluntary external urethral sphincter contraction. The test was repeated by interrupting the urinary stream with external urethral sphincter electrostimulation. The electromyography response of the internal urethral sphincter to the suppression and interruption of voiding was documented before and after internal urethral sphincter anesthetization. RESULTS Suppression of the reflex detrusor contraction as well as of urinary stream interruption by external urethral sphincter contraction voluntarily or by electrostimulation resulted in a significant detrusor pressure decrease (p <0.01) and urethral pressure increase (p <0.001). Internal urethral sphincter electromyography activity, which normally disappears during voiding, was still present. After internalurethral sphincter anesthetization subjects suppressed the reflex detrusor contraction by voluntary external urethral sphincter contraction for a mean of 62.6 +/- 9.6 seconds, after which involuntary voiding occurred. The internal urethral sphincter showed no electromyography activity. CONCLUSIONS The external urethral sphincter induces continence by preventing internal urethral sphincter relaxation at the detrusor contraction, which is suggested to be reflex in nature and is called the voluntary urinary inhibition reflex, and by mechanically compressing the urethra. Contraction of the external urethral sphincter, which is a striated muscle, mechanically occludes the urethra for a few seconds, by which time the detrusor has relaxed as an effect of the voluntary inhibition reflex.

Etiology of the resting myoelectric activity of the levator ani muscle: physioanatomic study with a new theory.

Abstract Of all the striated muscles in the bodies of mammals, only the pelvic floor muscles, which include the levator ani (LA), have resting electric activity. The cause and function of this resting myoelectric activity are not exactly known. The current study investigated the effect of intraabdominal pressure (IAP) and visceral weight on the electromyographic (EMG) activity of the LA, seeking to elucidate its cause and function. A series of 18 subjects (12 women, 6 men, mean age 38.6 years) were subjected to laparoscopic cholecystectomy for calcular cholecystitis. Prior to cholecystectomy, the resting LA EMG and IAP were recorded with the patient in the recumbent and erect positions. During laparoscopic cholecystectomy, the IAP was elevated by CO2 insufflation in increments of 5 cm of H2O, and the LA EMG activity was recorded for the recumbent and vertical positions during inflation and after deflation at the end of the operation. In 5/18 patients in whom laparoscopic cholecystectomy was extended to open cholecystectomy, the IAP and LA EMG were also registered. The study also included histologic examination of the LA muscle from 15 cadavers (7 adults, 8 neonates). Levator ani EMG increased (p < 0.05) on standing. At operation, IAP elevation was associated with a significant increase of LA EMG activity. On deflation, the IAP and LA EMG activity level returned to the pre-insufflation state. In open cholecystectomy, the IAP was zero and the LA EMG recorded no activity for the recumbent position, but there was an activity for the vertical position. Histologically, the lateral part of the LA in the adult cadavers consisted solely of skeletal muscle fibers. Proceeding medially, smooth muscle fibers started to appear and gradually increase until, at the midportion, the LA split into two layers, a deep layer consisting of smooth muscle fibers and a superficial layer consisting of skeletal fibers. In neonates, the LA was composed of purely skeletal muscle fibers. The LA EMG activity seems to be related to both the IAP and the visceral weight. It is probably attributable to the presence of smooth muscle bundles in the LA muscle. The LA EMG activity increased with the elevation of the IAP and visceral weight, which resulted in increased muscle tone to oppose the augmented pressure or weight. This effect seems to be mediated through the straining-levator reflex. A chronic increase of IAP or visceral overload is suggested to affect muscle integrity and function.

Botulin Toxin in the Treatment of Nonrelaxing Puborectalis Syndrome

Purpose: To evaluate the results of botulin toxin injection in the external anal sphincter for the treatment of nonrelaxing puborectalis syndrome. Method: 15 patients (13 women, 2 men; aged 36–48 years) were treated with botulinum A toxin injection, using a dose of 25 IU diluted in 1 ml normal saline injected into the top loop of the external anal sphincter at the 3 and 9 o’clock positions. The mean follow-up period was 14.6 ± 3.3 (SD) months. Results: Two patients did not respond to the treatment while improvement occurred in 13. Straining at defecation disappeared and stool frequency was normalized. Improvement was maintained for a mean of 4.8 ± 1.4 SD months, after which time reinjection needed to be done. No adverse side effects were encountered. Conclusions: Botulin toxin injection is a simple, easy and safe method for the treatment of nonrelaxing puborectalis syndrome. It is to be considered after biofeedback has failed.

Levator ani muscle: new physioanatomical aspects and role in the micturition mechanism

Abstract The anatomy of the levator ani muscle was studied in relation to the urinary bladder. The study was performed on 23 cadavers by dissection and microscopic examination. The levator ani is funnel-shaped and consists of a transverse portion called the levator plate and a vertical portion called the suspensory sling. The levator plate is a cone and consists of two “lateral masses” and two “crura,” with the levator hiatus occupying its anterior part. Three crural patterns could be identified: classic, crural overlap, and crural scissors. The levator crura are connected to the intrahiatal organs by the hiatal ligament; the pubovesical ligament constitutes the anterior part of this ligament. The suspensory sling forms a vertical cuff around the intrahiatal organs, from which it is separated by a “tunnel septum.” Its urethral portion ends in multiple fibrous septa, which penetrate the striated urethral sphincter. The levator ani plays an important role in bladder-neck fixation provided by the suspensory sling and hiatal ligament. Levator ani and hiatal ligament subluxation leads to ptosis of the urinary bladder. Furthermore, the present study demonstrates that the urethra is located in the infralevator compartment and is thus protected from the effect of intraabdominal pressure. A chronic increase in intraabdominal pressure leads to levator subluxation and sagging and to urethral exposure to intraabdominal pressure, which seems to interfere with the micturition mechanism. The infralevator location of the urethra might have a bearing on the pathogenesis and treatment of stress urinary incontinence.

A Concept of the Anatomy of the Anal Sphincter Mechanism and the Physiology of Defecation

A review of the new concepts of the anatomy of the anal sphincter mechanism and the physiology of defecation is presented. The external sphincter is a triple-loop system; each loop can function as a separate sphincter through voluntary inhibition action and mechanical compression. Stress defecation resulting from internal sphincter damage is described. A new technique for repair of rectal incontinence is presented, which depends on inducing continence not only by mechanical compression, but also by voluntary inhibition. The mechanism of defecation and rectal continence is described and four types of incontinence presented. Also, the mechanism of both the levator dysfunction syndrome and prolapse is demonstrated and a technique of repair is presented. The study defines two types of rectal anomalies: suprahiatal and infrahiatal. The role of the embryonic anorectal sinus, anorectal band, and epithelial debris in the genesis of perirectal suppuration, chronic anal fissure, pruritus ani, and hemorrhoids is described. The communicating veins, identified between the hemorrhoidal and vesical plexuses, offer an explanation for the vague pathologic aspects of recurrent bacteriuria, urethral discharge, cervicitis, and vaginitis, and provide a proper line for their treatment. They also serve to perform a new radiographic technique—anal cystography—and to administer drugs, including chemotherapeutics, in the treatment of pelvic malignancies.

Contraceptive efficacy of polyester-induced azoospermia in normal men

The contraceptive effect of a polyester sling applied to the scrotum was studied in 14 men. The suspensor was worn for 12 months. Follow-up investigations comprised periodic check of semen character, testicular size, rectal-testicular temperature difference, serum reproductive hormones and testicular biopsy. The electrostatic potentials generated by friction between the polyester suspensor and the scrotal skin were determined. Female partners used contraceptives until the men became azoospermic. After 12 months, the suspensor was abandoned and the aforementioned investigations were performed again. In the suspensor-wearing period, all men became azoospermic after a mean of 139.6 +/- 20.8 sd days, with decrease in both testicular volume (P less than 0.05) and rectal-testicular temperature difference (P less than 0.001). Serum reproductive hormones showed no significant change (P greater than 0.05). Seminiferous tubules revealed degenerative changes. No pregnancy occurred during this period. The polyester suspensor generated electrostatic potentials (mean 366.4 +/- 30.5 sd volt/cm2 by day and 158.3 +/- 13.6 sd volt/cm2 by night). In the suspensor-release period, the sperm concentration returned to the pre-test level in a mean period of 156.6 +/- 14.8 sd days. Likewise, the testicular volume and rectal-testicular temperature difference were normalized. The 5 couples, who had planned to become pregnant, conceived. The azoospermic effect of the polyester sling seems to be due to two mechanisms: 1) the creation of an electrostatic field across the intrascrotal structures, and 2) disordered thermoregulation. To conclude, fertile men can be rendered azoospermic by wearing the polyester sling. It is a safe, reversible, acceptable and inexpensive method of contraception in men.

Study of the pelvic floor muscles in vaginismus: a concept of pathogenesis

BACKGROUND Neither the cause of vaginismus nor the muscles involved are precisely identified. AIM To define the involved muscles and their role in the pathogenesis of vaginismus. METHODS The EMG activity of the levator ani (LA), puborectalis (PR) and bulbocavernosus (BC) muscles was studied in seven female patients (age (years): 25.6(mean)+/-1.2(S.D.)) and seven healthy volunteers who matched the patients in age. Recordings were performed at rest and during induction of vaginismus by a vaginal dilator. MAIN RESULTS Upon approximating the vaginal dilator to the vaginal introitus or introducing it into the vagina of the healthy volunteers, the EMG activity of the LA, PR and BC muscles showed no significant difference from the basal activity. In the patients, the basal EMG activity of the examined muscles was significantly higher than that of the healthy volunteers (P<0.05). Upon vaginismus induction, the muscles showed a significant increase of the EMG activity (P<0.01). The latency recorded a mean of 14.2+/-2.3, 13.9+/-2.3 and 14.1+/-2.2ms (P>0.05) in the LA, PR and BC muscles, respectively. The muscle response was momentary lasting a mean of 31.2+/-5.7s. It was reproducible provided an off-time of a mean of 13.2+/-2.3s was observed. CONCLUSION The pelvic floor muscles of vaginismus patients exhibited increased EMG activity at rest and on vaginismus induction; the cause is unknown. The concept of a disordered sacral reflex arc is put forward but needs further studies to be verified.