Rectal prolapse

A full-thickness, circumferential intussusception of the rectal wall

• Can also be partial

Epidemiology

• Uncommon - 0.5% of population

Risk factors

• Women >50yo (women make up 90% of patients)
• Prior pelvic surgery
• Chronic straining and constipation
• Chronic diarrhoea
• Vaginal delivery
• Multiparity
• Pelvic floor defects
• Neurologic disease/injuries
• Men tend to get it <40yo when they get it - uncommon
• Young patients with prolapse often have psychiatric conditions (autism/developmental delay) and take constipating medications

Pathophysiology

• Not completely known
• Commonly-found anatomic defects in patients with prolapse:
  • Diastasis of levator ani
  • Abnormally deep cul-de-sac
  • Redundant sigmoid colon
  • Patulous anus
  • Lack of fascia attachments of the rectum against the sacrum
• Theories:
  • Sliding hernia through defect in pelvic fascia (Moschowitz)
  • Circumferential intussusception of rectum (Broden and Snellman)
• Varies in severity from intra-rectal or internal rectal prolapse to external rectal prolapse
• Usually has a progressive course from transient self-reducing prolapse during defecation, to prolapse requiring digital self-reduction, to stable prolapse that may present with ulceration and even non-reducible incarcerated prolapse with necrosis in some cases
• Differentiate full-thickness vs partial-thickness. Partial thickness is just mucosa and usually looks similar to haemorrhoids, in that it is linear rather than concentric folds.

Presentation

• Sensation of external tissue after defecation (or continuously)
• Rectal bleeding/mucus discharge after defecation, especially with chronically incarcerated prolapse
• Faecal incontinence (due to impaired anorectal sensation) - 50-75%
• Tenesmus
• Constipation
• Urinary incontinence
• Pudendal neuropathy seen in 50%
• There are case reports of incarcerated and even strangulated rectal prolapse, but this seems to be very rare, and occurs in the setting of a giant prolapse that has reached venous strangulation due to being incarcerated. If it can be reduced, it's not strangulated.
  • If the prolapse cannot be reduced or there is mucosal necrosis, need emergency resection of the prolapsed rectum, possibly meaning Altemeier's perineal rectosigmoidectomy

Examination

• Look initially in lateral decubitus, but best way to diagnose is with the patient sitting on a commode and bearing down
• Often have a patulous anus and diminished resting tone and squeeze pressures
• Differentiate from prolapsed rectal mucosa or prolapsed haemorrhoids - radial mucosal folds, possibly with grooves along haemorrhoid cushions. A complete prolapse has circular folds.
• Consider proctoscopy to look for rectal ulcer (seen in 15%). Often see erythema at 5-6cm which is the leading edge of the prolapse.

Workup

1. Exclude cancer - colonoscopy (always)
2. Is it reproducible clinically?
   1. Defecography can identify occult prolapse, and document coexisting disorders (rectocoele, cystocoele, vaginal vault prolapse, enterocoele, sigmoidocoele)
3. Constipation workup if indicated (see separate topic)

Complications

• Solitary rectal ulcer (15%)

Initial management of painful, symptomatic prolapse

• Sugar (lots), either sit in it or place gentle pressure on muscle, and it will reduce over an hour or so
• Salt can also be used

Medical

• Avoid dehydration, stool bulking agents and softeners - but this is not a solution
• Enemas or suppositories can help with evacuation

Surgery

Goals:

• • Narrowing of anal orifice
  • Obliteration of the PoD
  • Restoration of the pelvic floor
  • Decreased rectosigmoid redundancy
  • Fixation of rectum to sacrum

Choice of approach

• • Abdominal approach is preferred, if the patient is a surgical candidate
    • If pre-existing constipation: ventral mesh rectopexy +/- resection (if there is a redundant sigmoid colon - generally the only situation where resectional procedures are used)
    • No constipation: Ventral or posterior rectopexy
    • Incontinence: posterior rectopexy
  • Unfit for abdominal approach/anaesthetic
    • Short segment (1-3cm): Delorme's
    • >3cm: Altemeier's

Abdominal approach - lap or open rectopexy

• • Rationale is to fix the rectum to provide adequate upwards tension to prevent a recurrence, but allow adequate evacuation during defecation
  • Recurrence rate <5%
  • Ventral rectopexy +/- mesh: expose the sacral promontory just inferior to iliac vessels, mobilise the rectum anteriorly down to pelvic floor, suture the rectum to a mesh or suture, and suspend the suture/mesh from the sacral promontory. Consider closing peritoneum again to prevent SBO/pelvic adhesions.

• Posterior rectopexy (Wells procedure): Mobilise the rectum posteriorly or both posteriorly and anteriorly. The lateral stalks are preserved to avoid constipation except in patients with faecal incontinence. This is followed by fixation of the rectum to the sacral promontory with sutures or mesh.
• Anterior mesh rectopexy (modified Ripstein procedure): anteriorly-based mesh sling for fixation of the rectum to the sacral hollow
• Resection rectopexy: Mobilise sigmoid colon and rectum, resect a segment of the sigmoid, anastomose the remaining colon to the rectum, and suture the rectum to the sacral promontory.
• Fixation:
  • Suture or mesh are appropriate
  • Suture: use non-absorbable e.g. 0 Ethibond to form horizontal mattress sutures in presacral fascia, at or just below the level of the sacral promontory, but only on one side of the rectal mesentery
  • Mesh: Can use either non-absorbable or biologic mesh with seemingly no difference in complication or recurrence rates

Perineal approach

• • Typically reserved for more comorbid patients
    • Less pain, earlier return of bowel function and walking than abdo operations
    • Was thought to have higher recurrence rates, but systematic reviews have shown similar rates
  • Prolapse is resected but without concomitant fixation
  • Delorme's procedure (mucosal sleeve resection)
    • Good for patients with a short (<3-5cm) prolapse
    • Recurrence up to 20%
    • Technique
      • GA or spinal
      • Prone jacknife or lithotomy position
      • Pull prolapse out and apply lone star retractors
      • Inject a lot of adrenaline in the submucosal plane
      • Circumferential incision in mucosa 1cm proximal to dentate line (or as low as can be reached - if the leadpoint is a bit higher, it's hard to pull the prolapse out far enough to get this low).
      • Submucosa and mucosal layers are dissected with diathermy from muscularis up to the most proximal part of the prolapse/apex
      • Excise stripped mucosa
      • 4-8 parallel longitudinal plicating sutures to join the two distant mucosal edges and also bunch up the intervening muscle - use PDS, place all the circumferential sutures, then push the prolapse back in and tie them one by one
      • Can also do separate bunching muscularis sutures and then separate mucosal anastomosis sutures
    • Cx:
      • Overall safe with short hospital stay
      • Bleeding
      • Anastomotic leak
      • Stricture
      • Diarrhoea
  • Stapled transanal rectal resection
    • Primarily for internal intussusception or partial thickness prolapse
    • Use circular stapler to essentially do the same thing as Delorme's procedure
    • High rate of complications - not recommended
  • Perineal proctosigmoidectomy (Altemeier's procedure)
    • GA/spinal
    • Lithotomy
    • Prolapse exteriorised and grasped with Allis clamps
    • Score 1cm above dentate line
    • Infiltrate with saline/LA and adrenaline
    • Full-thickness circumferential incision made through the rectum 1cm above the dentate line - until you see external aspect of the inner layer of rectal prolapse, including dividing mesorectum circumferentially
    • Continue dissection proximally along the rectum, detaching it from the mesorectum and attachments until the peritoneal cavity is entered in the pouch of Douglas (keep pulling down - combination of blunt dissection and LigaSure, particularly anteriorly)
    • Palpate sigmoid via the peritoneal cavity to assess how much redundant sigmoid is present, and identify a proximal transection margin (basically assess how much can come down to the planned perianal anastomosis)
    • Transect at rectosigmoid junction and hand off specimen
    • Levator muscles visualised - can be plicated posteriorly
    • Handsewn or stapled colo-anal anstomosis
      • Single layer, interrupted 2/0 Vicryl

Recurrence

• Repeat surgery is high-risk for developing ischaemia, after having the blood supply messed with previously
• Therefore need to know previous operations in detail