syndrome are paradoxical puborectalis contrac- tion (PPC) and puborectalis hypertrophy (PH).
When PPC is a functional disorder, it is also known as spastic pelvic floor syndrome or pelvic outlet obstruction. In patients with PPC, the structure of the puborectali muscle is normal but the puborectalis muscle cannot properly relax and contract.4 Therefore, the ideal treat- ment should aim at restoring the normal pub- orectalis function rather than at removing normal tissue.5
Jorge et al6 reported that the mean success rate for biofeedback for constipation was 68.5%, attributable to paradoxical puborectalis syn- drome. Other nonsurgical methods, such as bot- ulinum toxin injection and anal dilation, can also offer improvement to some patients with PPC who do not respond to biofeedback.7,8 Another, often neglected cause of puborectalis syndrome is PH. The etiology of PH is unclear.
The most common cause may be due to inflammation around the puborectalis, which causes puborectalis edema and stimulates hypertrophy. Gradually, the puborectalis loses its elasticity and cannot contract and relax func- tionally.9,10The authors reviewed 200 cases of PH and found sepsis around the puborectalis in 15%
to 30%.9Other factors such as congenital trauma and chronic diarrhea may also play a role in the development of PH. The structure of the pub- orectalis is abnormal among patients with PH.
Successful treatment cannot rely on biofeedback and other conservative methods, but does respond favorably to segmental excision of the puborectalis muscle.
Defecation is a complicated procedure in which pelvic floor muscles actively participate in the process. Rectal distention evokes the desire to defecate and induces relaxation of the anal sphincter. Under conducive circumstances, the act of defecation is completed by adoption of a suitable posture, contraction of the diaphragm and abdominal muscles to increase the intraab- dominal pressure, and relaxation of the two stri- ated muscle of the puborectalis and external anal sphincter. Puborectalis relaxation allows widen- ing and lowering of the anorectal angle. Coordi- nation between abdominal contraction and pelvic floor relaxation is crucial to this process (Fig. 26.1).
The puborectalis muscle is the most impor- tant component of the levator mechanism relat- ing to continence and defecation. This muscle originates from the inferior border of the pubis and the superior fascia of the urogenital diaphragm, and slings around both sides of the rectum to exert a pull and create the anorectal angle. If the puborectalis muscle cannot relax or even contracts during defecation, the anorectal angle will not change or may even decrease, defecation will be difficult, and constipation can ensue.1,2In 1964, Wasserman3 termed this syn- drome “puborectalis syndrome,” which is char- acterized by difficult and painful defecation and, occasionally, the inability to defecate for several days. On the basis of pathologic findings that have shown marked hypertrophy of the muscle fibers, this type of anorectal stricture was known due to spasmodic hypertrophy of the puborec- talis muscle. The main causes of puborectalis
26
Surgical Treatment of Puborectalis Hypertrophy
De-hong Yu and Hei-ying Jin
247
Diagnosis and Differential Diagnosis of Puborectalis Hypertrophy
Clinical Manifestation
The most common complaint of patients with PH is difficult defecation, including frequent attempts, a sense of incomplete evacuation, and prolonged straining. Approximately 50% of these patients require 15 to 30 minutes, and some require 60 minutes or more, to evacuate.
Although all patients desire to defecate once or more every day, they are usually unsuccessful.
Digital rectal examination shows that there is
increased anal sphincter tension in most of these patients and the puborectalis is clearly palpable, thick and stiff with a sharp border. When queried, these patients do try to push; however, the puborectalis has limited movement. The length of the anal canal is generally more than 4 cm and any attempt to force the examining finger through the anal canal causes more spasm and pain. There is a residue of dry and hard stool in the rectum even after defecation. Anorectal manometry generally confirms the functional length of the anal canal of more than 4 cm, although the resting pressures are in the normal range from 5 to 8.6 cm. The maximal squeeze pressures are generally 3 to 8 cm, without a significant amount of puborectalis contraction.
Thus, the ability of the puborectalis to contract is decreased in patients with PH. Although balloon expulsion test shows that most patients can expel the balloon, the time of expulsion is longer than that in nonconstipated individuals.
Colonic transit time study can show either rectal retention or colonic inertia, or it can be normal.
Puborectalis electromyography (EMG) shows many fibrillation potentials at rest without significant increases in action potentials when the patient is asked to squeeze or push (Figs.
26.2 and 26.3). Single-fiber electromyography (SFEMG) shows that the single-fiber conduction time (SFCT) is often longer than 3.4µsec and the fiber density increases.11–14Cui et al12studied 64 patients with PH and found that 92.2% showed abnormal EMG and 95.3% showed abnormal SPEMG. The EMG and SPEMG differences between PPC and PH are reported in Table 26.1.
Figure 26.1. Mechanism of the puborectalis muscle. Top: lateral view;
bottom: anteroposterior view.
Figure 26.2. Electromyography (EMG) of the puborectalis muscle of patients with puborectalis hypertrophy (PH). A: EMG at rest. B: EMG during straining.
The most important examination of PH is defecography. The anorectal angle becomes acute paradoxically in most cases of PH. At rest, the mean anorectal angle is 91 ± 11 degrees, and in most patients it is less than 90 degrees. During defecation, the mean anorectal angle is 93 ± 16 degrees and the angle is in fact less than 90 degrees in more than half of these patients.
These angles see little change between rest and defecation,9unlike the anorectal angle of normal individuals, which can increase by more than 20 degrees during defecation. Furthermore, the anal length becomes longer rather than shorter during evacuation as shown by defecography.
The most significant sign of PH in defecography is the “shelf ” sign, which can be noted in the lateral sitting position and is caused by the upper position of the anorectal junction without changing between rest and defecation (Fig.
26.4).9,10 This telltale sign can be noted in all patients with PH but is not seen in other patients with constipation. During a 10- to 15-minute evacuatory effort, little or none of the barium is
Table 26.1. The EMG and the SFEMG difference(s) between PPC and PH
PPC (n= 38) PH (n= 64) EMG
Rest Little fibrillation Great fibrillation potential potential Slight contraction Polyphasic motor Dominant in short
unit potential spike wave Exertion contraction High wave Low wave
amplitude amplitude
Push Paradoxical No or slight
electrical electrical activity activity SPEMG
SFCT 2.8µsec >3.4µsec
Fiber density Normal Increase(d) EMG, electromyography
SPEMG, single fiber electromyography PPC, paradoxical puborectalis contraction PH, puborectalis hypertrophy SFCT, single fiber conduction time
Figure 26.3. Anal manometry of PH; the final functional anal canal length is increased, and the anal canal pressures do not change between the rest and strain phases. The anorectal reflex is inhibited.
expelled.6,11,15 During videodefecography,16 the anorectal angle does not change or changes less than 3 degrees in patients with PH, while it can change more than 3 degrees between rest and defecation in patients with PPC or other reasons for constipation. Pathologic examination of the puborectalis demonstrates marked hypertrophy of the skeletal muscle in patients with PH.
Differentiation Between Paradoxical Puborectalis Contraction and Puborectalis Hypertrophy
Paradoxical puborectalis contraction is a very common disorder and is thought to be the sole cause of puborectalis syndrome, especially since biofeedback is successful in some patients with PPC.17Few series include patients with PH, and many surgeons believe that division of the pub-
orectalis should be abandoned due to the poten- tial for incontinence. However, in these authors’
experience, PH is also a very important cause of puborectalis syndrome. Ger et al14studied 116 patients with chronic constipation and found that the evacuation pressure by anorectal manometry (ARM) was divided into a normal relaxed pattern, an equivocal or nonrelaxed pattern, and a paradoxical contracted pattern.
Some patients with the equivocal or nonrelaxing pattern may have had PH. If PPC is the only cause of puborectalis syndrome, then theoreti- cally biofeedback should cure all patients.
However, at most only 70% of patients with PPC respond to biofeedback. In fact, more recent data suggest success rates of approximately 55%.5 Therefore, PH is an important cause of puborec- talis syndrome, although seldom recognized.
The differences between PPC and PH are sum- marized in Table 26.2.
Figure 26.4. The shelf sign. The top row shows the typical shelf sign preop- eratively at rest (left), squeeze (center), and defection (right); the barium retained in the rectum cannot be evac- uated. Postoperatively (bottom row), the anorectal angle is still 90 degrees at rest (left), while at straining (middle) and defecation (right) the anorectal angle is greater than 90 degrees and the barium can be evacuated.
Table 26.2. The differences between PPC and PH
PH PPC
Etiology Puborectalis organic abnormal Puborectalis functional abnormal
Length of the anal canal More than 4 cm Less than 4 cm
Evacuation pressure Not change or slightly decrease Increase paradoxical
EMG and SFEMG See Table 26.1 See Table 26.1
Shelf sign Yes No
Change of the anorectal angle in video defecography Less than 3 degrees More than 3 degrees
Paradoxical contraction No Yes
Biofeedback No response Respond mostly
Pathology of puborectalis Hypertrophy Normal
PPC, paradoxical puborectalis contraction PH, puborectalis hypertrophy EMG, electromyography
SFEMG, single fiber electromyography
Anal Dilation
Anal dilation is indicated for those patients who are unresponsive to conservative treatment.
Maria et al8treated 13 patients with puborectalis syndrome with 10-minute daily progressive anal dilations by insertion of three dilators sized 20, 23, and 27 mm in diameter, from the smallest to the largest, for a 3-month period. Six months after completion of treatment, all patients reportedly had good clinical outcome and none reported any incontinence. Spontaneous bowel movement frequency increased from zero to six per week and the need for laxative use decreased from 12 patients with a weekly mean of 4.6 to two patients once per week. During straining, tone measured with anal manometry decreased from 93 to 62 mm Hg 6 months after completion of therapy, and the anorectal angle measured by defecography during strain increased from 95 to 110 degrees. The authors concluded that daily progressive anal dilation should be considered as the first and simplest therapeutic procedure in patients with puborectalis hypertrophy.
However, daily progressive anal dilation is time- consuming and is not universally appealing to patients. Alternatively, after local anesthesia, a Pratt speculum can be inserted into the anus and gradually opened to its maximum aperture after which it is held in that position for 5 minutes.
These authors have treated 100 patients with PH by this method since 1999 with an 80%
improvement rate. There was decreased anal resting pressure and an increased anorectal angle; no incontinence was reported at a follow- up that ranged from 1 to 5 years.
Partial Resection of the Puborectalis Muscle
Indications
1. Meets diagnostic criteria of PH.
2. Defecation cannot be improved by conserva- tive methods and dilation.
3. An abscess around the puborectalis is found by intrarectal ultrasonography, computed tomography (CT) scan, or magnetic reso- nance imaging (MRI).
4. No colonic inertia or other abnormalities that can cause outlet obstruction-type constipa- tion are present.
Diagnostic Criteria of Puborectalis Hypertrophy
1. Difficult defecation, including frequent attempts at defecation, a sense of incomplete evacuation, and/or prolonged straining with incomplete evacuation.
2. Elongated anal canal confirmed by digital examination, anal manometry, and defecography.
3. Anal canal resting pressure is normal or slightly increased, and there is no signi- ficantly change during evacuation.
4. Fibrillation potential is common at rest, while the action potential does not significantly change when the patient squeezes or pushes;
SFCT is more than 3.4µsec.
5. No paradoxical contraction is found by digital anal examination, manometry, or videodefecography.
6. “Shelf sign” can be found in all patients, and the anorectal angle changes less than 3 degrees between rest and push during defecography.
7. Does not respond to biofeedback.
8. PH can be found on pathologic examination.
9. PPC has been excluded.
Treatment
Conservative Treatment
Patients with PH and mild symptoms of consti- pation should initially be given conservative treatment, which includes (1) a high-fiber diet of at least 15 g per day and adequate water intake of 2000 to 3000 mL per day; (2) physical exercise (habit training is also very important for patients with PH); (3) bulk or lubricated laxa- tives, which can be given if evacuation is very difficult and painful, but stimulant laxatives should be avoided; and (4) puborectalis exer- cises in the knee–chest position, with contrac- tion and relaxation of the puborectalis at least 500 times per day to help recover the elasticity of the puborectalis. According to these authors’
experience, conservative treatment in approxi- mately 200 patients with PH has resulted in significant symptomatic relief in 50%.
Contraindications
1. Findings of PPC.
2. Identification of one or more abnormalities that cause obstruction, constipation, or colonic inertia.
Surgical Procedure
Either sacral or lumbar anesthesia is adminis- tered prior to positioning the patient. The surgeon should stand on the patient’s left side.
The patient is then placed in the prone jack-knife position with the buttocks retracted with adhe- sive straps, keeping the posterior median raphe in the midline. A low 3- to 5-cm midline incision is made from the posterior anal verge to the tip of the coccyx. A longer incision does not facili- tate superior exposure. The incision is subse- quently deepened by diathermy until the tip of the coccyx is exposed, as the coccyx is the land- mark of the superior border of the puborectalis muscle. The surgeon’s left index finger is intro- duced into the rectum and the puborectalis muscle is elevated into the surgical field. The superior border of the puborectalis muscle lies just beneath the tip of the coccyx, to which it is attached. Curved clamps are used to separate the puborectalis muscle posteriorly and laterally.
Simultaneously, the finger in the rectum is used to guard against enterotomy. The puborectalis is clamped laterally and then the intervening muscle is excised for a width of approximately 1.5 cm. The remaining end of the muscle is ligated with 00 silk sutures or absorbable sutures. After resection, a well-defined V-shaped defect should be palpable by the finger in the rectum. Any remaining fibers on the wall of the rectum should be resected and not merely divided. The wound is irrigated and, if necessary, a small drain is inserted. Finally, the subcuta- neous tissue and the skin are closed with inter- rupted sutures. The surgical treatment of PH is illustrated in Figures 26.5 to 26.8.
Results and Follow-Up
Between 1985 and 2003, 69 cases of PH fulfilled the inclusion criteria outlined earlier in this chapter and subsequently underwent partial division of the puborectalis muscle. The day
following the procedure, all patients reportedly had frequent discharge of gas, and within 7 days 90% of the patients were passing soft or formed stools at least once daily. Defecography per- formed 4 weeks after the procedure revealed a flatter anorectal angle during evacuation than that noted prior to surgery. The defecography of two typical patients are shown in Figures 26.9 and 26.10. At a median follow-up of 6 years (range 1–18), 42 (61%) of patients can freely defecate whereas 19 (28%) still experience some difficulty and require laxatives or have subsequent anal dilation. Six patients evac- uate with significant difficultly and require the use of enemas for complete evacuation.
The two patients who evacuate less than once weekly had endorectal ultrasonographic findings of perineal abscess. In these patients, a second division of the puborectalis was under- taken. Three patients reported slight inconti- nence to gas and liquid while all patients were fully continent.
Wasserman3 proposed spasmodic hypertro- phy of the puborectalis muscle. He reported on four patients, three of whom underwent partial resection of the puborectalis muscle with excel- lent results. Partial resection of the puborec- talis muscles was advocated by Wallace and Madden,18based on their series of 33 adults and 11 children. Kawano et al19 reported relief of symptoms in three of seven patients who under-
Figure 26.5. Surgical procedure for PH: an incision is made while the patient is in the prone jackknife position (PH, puborectalis hypertrophy).
Figure 26.6. Surgical procedure for PH: dissection (PH, puborectalis hypertrophy).
Figure 26.7. Surgical procedure for PH: clamping the puborectalis
muscle (PH, puborectalis hypertrophy). Figure 26.8. Surgical procedure for PH: resection (PH, puborectalis hypertrophy).
Figure 26.10. Preoperative (top) defecography. Note the shelf sign at rest (left) and during attempted but unsuc- cessful evacuation (right). Postoperative defecography (bottom) shows normal anatomy at rest (left) and during suc- cessful evacuation (right).
Figure 26.9. Preoperative defeco- graphy (top) and postoperative defeco- graphy (bottom).
went partial resection of the puborectalis muscle. However, in the series of Barnes et al,20 only two of nine patients who received complete division of the puborectalis muscle obtained relief, while seven had symptomatic improve- ment. This report suggests that complete divi-
sion is not as effective as partial resection, and the rate of fecal incontinence is higher after com- plete puborectalis division. Liu et al21studied 149 patients who underwent partial division of the puborectalis muscle and found complete resolu- tion of symptoms and no incontinence in 134
than 1.5 cm) is resected, the cut ends may re- adhese and cause stricture recurrence. Postoper- ative balloon dilation of the rectum may prevent adhesion recurrence. The authors treated two patients whose symptoms recurred owing to adhesions between the resected ends who subse- quently underwent a second procedure.
Conclusion
Constipation is a complex disorder, the under- standing of which remains superficial. Partial resection of the puborectalis muscle only releases the abnormal mechanism of defecation.
This procedure, therefore, should be restricted to those patients who have definite evidence of outlet obstruction caused by hypertrophy of the puborectalis muscle and who fail to respond to conservative therapy. It is also imperative to correct inappropriate bowel habits and diet prior to surgery.
Both PPC and PH are poorly understood con- ditions which require further investigation. Pub- orectalis hypertrophy is a condition that causes outlet obstruction constipation. Although it has some similarity with PPC, it is an organic disor- der caused by hypertrophy of the puborectalis muscle due to inflammation, congenital struc- ture, trauma, or other etiologies. While PPC is a functional disorder and the structure of the pub- orectalis is normal, it does respond to biofeed- back and botulinum toxin type-A injection, unlike PH. Only those patients who have definite evidence of outlet obstruction caused by hyper- trophy of the puborectalis muscle, and who fail to respond to conservative therapy, should undergo division of the puborectalis muscle.
(90%) patients. The results of division of the puborectalis muscle are summarized in Table 26.3.
Two factors may explain the significant vari- ability of the operative results. One is the diver- sity in the operative indications among the various series. For instance, Kamm et al22 included megarectum as an indication for pub- orectalis division. Other series include patients who have had one or more concomitant causes of outlet obstruction constipation. Puborectalis division is only valuable in patients with PH without other concomitant causes of constipa- tion. A second factor is the differing surgical techniques among the surgeons. There are three methods for this procedure: posterior partial resection; posterior division; and lateral, unilat- eral, or bilateral resection. Division of the pub- orectalis alone may not allow complete muscle end retraction, as adhesions may develop and can cause symptom recurrence. For this reason, the partial resection should extend from the pos- terior rectal wall to the puborectalis muscle, dissecting both cut ends as widely as possible.
At least a 1.5-cm width of muscle should be resected.
Why does partial resection of the puborectalis muscle fail? The reasons for failure may include concomitant unrecognized anatomic outlet obstruction due to either intussusception or rectocele. The authors emphasize the importance of thorough preoperative physiologic evaluation and exclusion or successful treatment of all other causes of constipation. Incompletely resected adhesions or fibrous bands between the pub- orectalis muscles and rectal wall may result in a persistent stricture and continued symptoms. If an insufficient width of puborectalis muscle (less
Table 26.3. The results of division of the puborectalis muscle
Success rate
Reference Diagnosis Procedure n n %
Wasserman (1964)3 Puborectalis syndrome Posterior partial resection 4 3 75
Wallace (1969)18 Puborectalis syndrome Posterior partial resection 44 33 75
Keighley (1984)24 Outlet syndrome Partial division 7 1 14
Barnes (1985)20 Chronic constipation Partial division 9 2 22
Kamm (1988)22 Chronic constipation Partial division 18 4 22
Kawano (1997)19 Puborectalis syndrome Partial resection 7 3 43
Yu (1990)23 Puborectalis syndrome Partial resection 18 15 83
Liu (2001)21 Puborectalis syndrome Partial resection 149 134 90
Xu (2002)25 Puborectalis hypertrophy Partial resection 29 28 97
References
1. Bharucha AE. Obstructed defecation: don’t strain in vain! Am J Gastroenterol 1998;93:1019–1020.
2. Schouten WR, Briel JW, Auwerda JJ, van Dam JH, Gosselink MJ, Ginai AZ, Hop WC. Anismus: fact or fiction? Dis Colon Rectum 1997;40:1033–1041.
3. Wasserman JF. Puborectalis syndrome, rectalis ster- nosis due to anorectal spasm. Dis Colon Rectum 1964;7:87–98.
4. Prather CM, Ortiz-Camach CP. Evaluation and treat- ment of constipation and fecal impaction in adults.
Mayo Clin Proc 1998;73:881.
5. Lau CW, Heymen S, Alabaz O, Iroatulam AJ, Wexner SD.
Prognostic significance of rectocele, intussusception, and abnormal perineal descent in biofeedback treat- ment for constipated patients with paradoxical pub- orectalis contraction. Dis Colon Rectum 2000;43:
478–482.
6. Jorge JM, Habr Gama A, Wexner SD. Clinical applica- tions and techniques of cinedefecography. Am J Surg 2001;182:93–101.
7. Ron Y, Avni Y, Lukovetski A, et al. Botulinum toxin type- A in therapy of patients with anismus. Dis Colon Rectum 2001;44:1821–1826.
8. Maria G, Anastasio G, Brisinda G, Civello IM. Treatment of puborectalis syndrome with progressive anal dila- tion. Dis Colon Rectum 1997;40:89–92.
9. Yu DH, Meng RG, Li SZ. Puborectalis syndrome: a cause of obstinate constipation. Zhonghua Wai Ke Za Zhi 1989;27:267–268.
10. Lu R, Chen D, Yu DH. Defecographic diagnosis of pub- orectalis syndrome. Zhonghua Yi Xue Za Zhi 1991;71:
633–634.
11. Fucini C, Ronchi O, Elbetti C. Electromyography of the pelvic floor musculature in the assessment of obstructed defecation symptoms. Dis Colon Rectum 2001;44:1168–1175.
12. Cui Y, Hu HH, Cheng JS, Zheng HM, Liu Y. Significance of electromyography and single fiber electromyography in puborectalis. J Clin Electroencephalogr 1996;5:202–
204.
13. Fleshman JW, Dreznik Z, Cohen E, Fry RD, Kodner IJ.
Balloon expulsion test facilitates diagnosis of pelvic floor outlet obstruction due to nonrelaxing puborec- talis muscle. Dis Colon Rectum 1992;35:1019–1025.
14. Ger GC, Wexner SD, Jorge JM, Salanga VD. Anorectal manometry in the diagnosis of paradoxical puborec- talis syndrome. Dis Colon Rectum 1993;36:816–825.
15. Jorge JM, Wexner SD, Ger GC, Salanga VD, Nogueras JJ, Jagelman DG. Cinedefecography and electromyography in the diagnosis of nonrelaxing puborectalis syndrome.
Dis Colon Rectum 1993;36:668–676.
16. Pfeifer J, Oliveira L, Park UC, Gonzalez A, Agachan F, Wexner SD. Are interpretations of video defecographies reliable and reproducible? Int J Colorectal Dis 1997;12:67–72.
17. Glia A, Gylin M, Gullberg K, Lindberg G. Biofeedback retraining in patients with functional constipation and paradoxical puborectalis contraction: comparison of anal manometry and sphincter electromyography for feedback. Dis Colon Rectum 1997;40:889–895.
18. Wallace WC, Madden WM. Experience with partial resection of the puborectalis muscle. Dis Colon Rectum 1969;12:196–200.
19. Kawano M, Fujiyoshi T, Takasi K, et al. Puborectalis syndrome. J Jpn Soc Coloproctol 1997;40:612.
20. Barnes PRH, Hawley PR, Preston DM, et al. Experiences of posterior division of the puborectalis muscle in the management of colonic constipation. Br J Surg 1985;72:475–477.
21. Liu YG, Zang JX, Li YW, Gao CF, Xu Z. Treatment of musculi puborectalis syndrome with partial resection of musculi puborectalis: analysis in 149 cases. J LuoYang Med Coll 2001;19:17–18.
22. Kamm MA, Hawley PR, Lennard Jones JE. Lateral divi- sion of the puborectalis muscle in the management of severe constipation. Br J Surg 1988;75:661–663.
23. Yu DH, Cui FD. Surgical treatment of puborectalis syn- drome. J Pract Surg 1990;10:1599–1600.
24. Keighley MR, Shouler P. Outlet syndrome: is there a sur- gical option: J R Soc Med 1984;77(7):559–563.
25. Xu DK, Chen LL. Clinical observation of the therapeutic effect of 2 different surgical procedure for pubotrectalis hypertrophy. Chin J Coloproctol 2002;22:31–32.
