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ANAL INCONTINENCE AND THE PLASTIC SURGEON

Sr Tambwekar*, Kumkum Khadalia**
*Consultant Plastic Surgeon; **Asst. Plastic Surgeon; Bombay Hospital, Mumbai.

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Anal incontinence may need to be corrected by the creation of a neoanal sphincter by providing innervated muscle tissue from a nearby muscle. Any such procedure would need the application of the basic principles of plastic surgery. So anal incontinence cases also do get referred to the plastic surgeon.

Definition[9]

Faecal incontinence can be defined as the involuntary excretion of faeces at an inappropriate time or in an inappropriate place more than twice in the last month.

Minor incontinence is the inadvertent escape of flatus or the soiling of undergarments which can usually be tackled by attention to local causative conditions.

Major incontinence is the involuntary excretion of stools of normal consistency.

Causes[6]
o Descent Perineal descent Prolapsing haemorrhoids Rectal prolapse	oDeficiency Congenital abnormalities Spina bifida, Meningocoele, Myelomeningocoele, Aganglionic megacolon Imperforate anus
oDestruction Malignant tumour Irradiation	oDamage Impalement injury Fracture pelvis Obstetric injuries Deviant sexual practice Insertion of foreign bodies Surgical procedures for piles, fissure, fistula
oDenervation Spinal injury Neuro-surgical procedure
oDebility Illness Old age-faecal impaction	oDementia Senility, psychological abnormality

 

Study of a case

This includes the usual history, examination and investigation. Today there is a gamut of investigative procedures8 available. Some help in making a complete diagnosis and in deciding on the therapeutic regimen. Some investigative procedures help in making an objective documentation of a case before and after therapy, in order to prove the efficacy of the chosen therapeutic regimen.

Anal surgical repair

The surgical procedure suitable for a particular case can only be decided upon after a total understanding of the underlying pathophysiologic abnormality in that case.

Role of the plastic surgeon

Cases of anal incontinence with associated loss of perineal skin and those that warrant the use of encirclement myoplasty for the creation of a neoanal sphincter are often referred to the plastic surgeon.

These cases include :

• Congenital anomalies
• Muscular denervation
• Destruction of more than half of the sphincter

The most frequently used procedures are the graciloplasty and the gluteoplasty.

History of gluteoplasty and graciloplasty[4]

The first documented use of the gluteus maximus for anal sphincter repair dates back to 1902. Thereafter various modifications and improvements have been tried. The gracilis anal sphincter myoplasty was introduced in 1952. Over the subsequent years the results of the graciloplasty proved to be disappointing and attention once again reverted to the gluteus maximus in 1981.

Types of anal surgical repair

* Sphincter repair o Apposition of sphincter muscles o Overlapping of sphincter muscles o Reefing of sphincter muscles

* Postanal repair o Levator ani and external anal sphincter muscle plication o Puborectalis repair

* Neoanal sphincters o Muscle transposition Gluteus maximus Gluteus maximus with neuromuscular stimulator Gracilis Gracilis with neuromuscular stimulator Vastus internus Adductor longus

o Free muscle graft - previously denervated donor muscle is transplanted over the surface of the levator ani from where its reinnervation is anticipated to occur Palmaris longus Sartorius

* Artificial sphincter - silicone rubber filled with a radio-opaque solution

* Neuroprosthesis implant - stimulator implanted in vicinity of pudendal nerve

* Anal slings - silastic, fascia lata, Thiersch procedures

Comparison of the conventional gluteus maximus and gracilis myoplasties[3],[4]
Gluteus maximus	Gracilis
o It functions as an accessory muscle to continence	o It brings about adduction of the hip
o It can encircle the anus with muscular non-tendinous powerful voluntary muscle able to maintain a basal tone	o It provides a tendinous sling around the anus
	o Unable to maintain muscle contraction despite training
o Its lower half has an independent neurovascular pedicle	o Because of the pattern of blood supply there may be necrosis of the distal part after local transposition
o The neurovascular pedicle is subjected to less traction	o There may be traction on the obturator nerve
o Traction on the pedicle does not increase with contraction of the muscle	o Traction on the neuorvascular pedicle increases when the muscle contracts
o The myoplasty produces a double curvature of the anal canal	o The myoplasty enhances the natural anorectal angle

 

Fig 1 :

 

Fig : 2 Making the area of the gluteus maximus. Fig : 3 The muscle slips turned over to show the neurovascular pedicle.

In 1987 postoperative intermittent muscle stimulation2 was used following graciloplasty. This was based on the concept of the implantable pulse generator used in dynamic cardiomyoplasty, which was introduced in 1985. In 1988 the implantable pulse generator was used with the graciloplasty. Now the results of the dynamic graciloplasty became comparable with the results of gluteoplasty. The first gluteoplasty with implantation of the pulse generator was done in 1992.

History of gluteoplasty[3]

• Muscle slips

1902 Chestwood; 1929 Stone

CASE REPORT

A 23 year old male patient was referred for anal incontinence. Primarily he was treated for imperforate anus by colostomy followed by transfer of the rectum to the perineum and then closure of the colostomy. He remained incontinent ever since. This created a social problem, he was not sent to school and the family withdrew into social isolation due to the uncontrollable foul odour in their house.

On examination the anal opening was patulous as there was no external sphincter and the internal sphincter was also absent. The primary transfer had achieved a fairly satisfactory angle at the levator ani, however, due to the absence of the internal sphincter, continence was not achieved.

For the operation, the patient was placed in the jackknife position. An incision was made through the old midline operation scar. The rectum and the levator ani was identified. It was felt that there was a need for the repair of the internal as well as external sphincter.

The circular muscle was plicated to reinforce the internal sphincter. The levator ani sling was tightened. The gluteus maximus muscle was selected to provide a good muscular external sphincter. The gracilis was not selected, as it would not provide sufficient muscle tissue to encircle the anus.

The left gluteus maximus was separated from the subcuta neous tissue. The width and length necessary to make two proximally based muscle strips, which could go around the anus and cross over each other posterior to the anus was estimated. The required measurements were taken and about one third of the muscle width was cut through distally and then dissected upwards towards the sacrum until the neurovascular pedicle emerging from the lower border of the pyriformis muscle was visualised. Keeping this intact, two equal slips were made.

A curvilinear incision was made posterior to the anus and a subcutaneous tunnel was dissected around the anus. The two strips were crossed over and passed through the right and the left tunnels. They were stitched to each other at the anterior crossing. The ends were crossed over each other posterior to the anus and sutured together adjusting the tension sufficient to give a firm grip on an index finger placed in the anus. The incisions were then sutured.

This procedure is somewhat like the one described by Gueliuckx et al. The difference is that the muscle slips are not stitched to the ischial tuberosity. Thus the muscle, which now surrounds the anus, is able to act as a free-floating dynamic sling.

 

Fig 4 : The muscle slips encircling the anus, placed subcutaneously.

 

Fig : 5 The patulous, asphincteric anus, showing the scar of the previous surgery. The patient is in the jackknife position.

The wounds healed primarily. No special efforts were required to train the patient to use his gluteus as a sphincter. After an initial period of moderate constipation, which was relieved by repeated enemas, he remained continent and was able to pass stools at will, twice a day. Slowly he gained the control for flatus as well. Over the last three years he has remained continent.

CONCLUSION

Through the 20th century, starting from 1902, various procedures have been performed to reconstruct the anal sphincter apparatus using different muscles in cases where direct sphincter repair is not possible. Such cases include those in which the sphincter muscles are absent or denervated and those where previous attempts at sphincter repair have failed or where more than half the sphincter is destroyed.

Fig : 6 The patulous, asphincteric anus, showing the scar of the previous surgery. The patient is in the jackknife position.

Of all the muscles that have been utilised, gracilis and gluteus maximus have stood the test of time with variations and improvement in results. The gluteus maximus has been shown to give more predictable results, as discussed earlier. Being a muscle of posture, its dynamism is constant, even during sleep. This muscle must always be considered as a solution to this problem in appropriate cases.

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REFERENCES

1.Bruining HA, et al. Creation of an anal sphincter mechanism by bilateral proximally based gluteal muscle transposition. Plast Reconstr Surg 1981; 67 : 70.

2.Cavina E, et al. Construction of a continent perineal colostomy by using electrostimulated gracilis muscles after abdominoperineal resection. Ital J Surg Sci 1987; 17 : 305.

3.Devesa JM, et al. Total fecal incontinence - A new method of gluteus maximus transposition. Dis Colon Rectum 1992; 35 : 339.

4.Guelinckx PJ, et al. Anal sphincter reconstruction with the gluteus maximus muscle. Plast Reconstr Surg 1996; 98 : 293.

5.Hentz VR. Construction of a rectal sphincter using the origin of the gluteus maximus muscle. Plast Reconstr Surg 1982; 70 : 82.

6.Mann CV, et al. Bailey and Love's short practice of surgery. 22nd edition. ELBS Chapman and Hall. Anal incontinence. 1995; 868.

7.Orgel MG, Kucan JO. A double-split gluteus maximus muscle flap for reconstruction of the rectal sphincter. Plast Reconstr Surg 1985; 75 : 62.

8.Sangwan YP, et al. Fecal incontinence. Surg Clinics of North America 1994; 74 : 1377.

9.Thomas TM, Egan M, Walgrove A, et al. The prevalence of faecal and double incontinence. Community Med 1984; 6 : 216.

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