HistoryThis syndrome was first proposed in 1966 by Parks et al, who, while observing rectal prolapse, found that the patient had hypotonia and decreased muscle tone of the pelvic floor muscular system and excessive prolapse of the anterior rectal wall, which prevented rectal emptying. Of the 100 patients seen in the anorectal unit reported by Parks et al. in 1966, 12 suffered from this syndrome. Subsequently, Henry et al. provided a concise definition of this syndrome, in which the perineal level is lowered beyond the sciatic tuberosity during forceful fecal evacuation. In recent years, as the use of fecal contrast has become more widespread in clinical practice, there has been an increasing number of reports of perineal descent syndrome.
This syndrome is not uncommon in clinical practice. It is more common in women than in men and is more common in menstruating women. It can occur at any age, but is rare in those under 30 years of age.
The cause of this syndrome is due to the prolonged squatting and excessive forceful defecation, which can weaken the function of the pelvic floor muscles and increase the normal rectal angle, and the vicious circle of anterior rectal wall mucosal prolapse, which transmits increased intra-abdominal pressure and prolapses the anterior rectal wall mucosa into the superior orifice of the anal canal. This anterior wall mucosal prolapse (AMP) can lead to a sense of incomplete fecal evacuation, and thus the patient further strains to evacuate feces, forming a vicious cycle. In addition, the patient is prone to this disease in multiple deliveries during menstruation.
This syndrome was first proposed by Parks (1966), who observed rectal prolapse in patients with hypotonia and muscle atrophy of the pelvic floor muscle system and excessive prolapse of the anterior rectal wall, thus affecting rectal evacuation. Most scholars agree that perineal descent syndrome is a concomitant lesion of endorectal condyloma or prolapse of the rectum. It is associated with obesity, advanced age, childbirth, anal surgery, or post-inflammatory strictures. Among them, prolonged excessive straining to defecate and birth injury are the main causes.
Clinical manifestations complain of a feeling of obstruction in the rectum, i.e., a sense of incomplete defecation, sluggishness and pain in the perineum, and difficulty in fecal expulsion. The main clinical feature is that the anal canal struggles during defecation and can often be accompanied by significant mucosal and hemorrhoidal prolapse.
Since this syndrome is often a concomitant pathological change of endorectal prolapse or rectal prolapse, this syndrome can manifest various symptoms of endorectal loops and rectal prolapse. The main symptoms include incomplete stool feeling, anal swelling, difficulty in defecation, increased stool frequency, perineal pain, partial incontinence, some patients have a history of applying various laxatives, a few have mucus and blood stools, and swelling in the anus after defecation or walking.
Physical examination: simulating defecation, the perineum is seen to be ballooning, the anal canal descends more than 2 cm, and there is obvious anal canal mucosa and hemorrhoid exstrophy. With rectal prolapse, rectal prolapse out of the anus is seen. The anal canal sphincter tone is reduced on finger palpation, and the patient is instructed to contract the anal canal with significantly reduced strength. Isolated ulcers may be found on the anterior rectal wall, and a weak area may be found on the anterior wall above the anal canal when there is anterior rectal prolapse.
Fecal imaging is a reliable method to diagnose perineal descent syndrome, not only to determine the position of the perineum at rest, but also to determine the degree of perineal descent during defecation. In addition, it can diagnose other pelvic floor relaxation disorders that often accompany perineal descent syndrome, such as endorectal condyloma, rectal prolapse, and rectal prolapse.
The diagnostic criteria for fecography in perineal descent syndrome are.
1.The perineal position is represented by the midpoint of the puborectal muscle pressure trace, and the horizontal line of the lower edge of the sciatic tuberosity is used as a reference. The perineal position in the resting phase before defecation is lower than the lower edge of the sciatic tuberosity by 2 cm, and/or the perineal descent during defecation is greater than 3 cm.
2, the upper part of the anal canal, that is, the midpoint of the anal canal-rectal union represents the perineal position, with the line from the lower edge of the pubic symphysis to the tip of the coccyx, that is, the pubic-caudal line as a reference; at normal rest, the upper part of the anal canal is located exactly at the lower edge of the pubic-caudal line, and the upper part of the anal canal is lower than the pubic-caudal line by 3 or 5 cm in menstruating women, and lower than 3 cm in others; or the drop in defecation is greater than 3 cm.
On rectal finger examination, the dilatation force of the anal canal at rest was reduced, and when the patient was instructed to do random contractions, the contraction force of the anal canal was significantly weakened.
On anoscopy, mucosal buildup in the anterior rectal wall was seen, blocking the mirror end.
On anal canal manometry, the resting and maximum systolic pressure of the anal canal can be reduced.
Diagnosis is confirmed based on the patient’s history of prolonged excessive straining to defecate, the examination reveals squatting nuisance anal canal descending more than 2 or 5 cm, and rectal finger examination with significantly reduced anal canal tone. However, it needs to be differentiated from simple internal hemorrhoid prolapse and rectal prolapse.
(I) Treatment
1.Non-surgical treatment
(1) Develop good defecation habits: develop good habits of regular defecation, avoid excessive forceful defecation, and avoid excessively long defecation time each time, no more than 10 min is appropriate; fiber preparations can be properly applied to help defecation, thus avoiding further aggravation of pelvic floor muscle damage.
(2) Strengthen anal lifting exercise: the function of the pelvic floor muscle is concentrated in the contraction and diastole of the anus, and this movement is coordinated by the internal and external anal sphincter and anal levator muscle through a complex mechanism.
(3) Active treatment of concomitant lesions: In order to reduce symptoms and avoid further damage to pelvic floor muscles, perineal descent syndrome accompanied by endorectal stasis or rectal prolapse should be actively treated for prolapse, interrupting the vicious circle between perineal descent syndrome, excessive forceful defecation and prolapse. First of all, injection therapy is used to strengthen the anal lifting exercise, and the efficiency is still possible.
2.Surgical treatment
If the treatment by injection is ineffective, or if the rectum is overlapped in the anal canal, surgery is feasible to correct the rectal overlapping. However, because the perineal descent syndrome is accompanied by pelvic floor muscle dysfunction, even if the diameter of the abdominal rectum is fixed or suspended, some symptoms may remain after surgery.
Since perineal descent syndrome is accompanied by some degree of pelvic floor muscle dysfunction, clinicians should avoid anal dilation treatment to avoid aggravating sphincter damage and leading to postoperative anal incontinence, and advise patients to establish the good habit of defecating regularly every morning, with each defecation not exceeding 7-10 min. Special emphasis should be placed on reducing the effort during defecation. Patients with constipation can use expansive laxatives as appropriate. If necessary, enemas can be used.
For patients with prolapsed mucosa of the anterior rectal wall or prolapsed internal hemorrhoids, sclerotherapy can be used, and if it is not effective, rubber band ligation therapy or surgical excision can be considered.
The main prevention from the improvement of fecal habits, in addition to the regular defecation, it is best to go to defecation when there is a clear sense of bowel movement, the use of sectional squeeze fecal method has a better prevention effect, can reduce the strength of anal struggle. It is advisable to eat more fresh vegetables, fruits and high-fiber foods. Long-term adherence to anal health exercises or qigong practice to lift the anus will help the pelvic floor muscle function recovery.