Perioperative management - Rehn-Delorme transanal mucosal resection

•  External full-wall rectal prolapse (grade III) in patients in whom abdominal surgery should be avoided (high-risk patients).
•  Internal rectal prolapse (intussusception) as seen in obstructive defecation syndrome (ODS) with rather careful indication by an experienced coloproctologist.

• Relative contraindication in large prolapse
• General inoperability
• No burden of suffering

Medical history
Is the prolapse present only during defecation and physical exertion or is it permanent?
Often, peranal passage of blood is reported, e.g., from a solitary rectal ulcer (benign, common in rectal prolapse, always anterior).
Is there constipation or diarrhea, possibly alternating?
Other complaints are a feeling of incomplete bowel evacuation (= repetitive trips to the toilet with intense, futile straining attempts), tenesmus and mucus discharge.
There is almost always fecal incontinence with adverse social implications. For example, proximity to a toilet must always be assured, and a period of fasting observed before leaving home.
In women, urinary incontinence in pelvic floor prolapse is often a concomitant manifestation.

Basic proctologic examination with inspection, palpation and proctorectoscopy

• Inspection/straining attempt: Regardless of how impressive advanced rectal prolapse may present: it may be easily overlooked if it only presents during defecation and if the patient avoids intense straining during the examination out of a sense of shame or - which is common - confuses straining with pinching. Often, the prolapse manifests only after several attempts at straining. If necessary, examine the patient in a squatting position or on the commode chair. Concentric mucosal folds are characteristic of complete rectal prolapse.
• Digital rectal examination: Active contraction and relaxation allow a rough assessment of the sphincter apparatus. With the patient straining, it may be possible to palpate an intussusception or rectocele. Mucosal induration may point to a solitary rectal ulcer.
• Proctoscopy: Intussusception is often (not always) recognizable as bulging of the anterior rectal wall through the anal canal when the proctoscope is withdrawn to the distal end of the anal canal and the patient is asked to strain.
• Rectoscopy: May be able to visualize a solitary rectal ulcer (always localized anteriorly).
  Distal proctitis beginning at the anorectal junction and abruptly ending 10-12 cm from the anal verge is often accompanied by rectal prolapse.

Functional diagnostic work-up

Defecography can confirm a prolapse; it can be dispensed with if there is a clear diagnosis

• Standard defecography
  In addition to rectal prolapse. standard defecography can also assess changes such as rectocele, intussusception and sigmoidocele. Since differential diagnosis defecography can detect both functional and morphological changes in the pelvic floor and rectosigmoid - as well as enteroceles in contrast enhanced studies - it is a powerful imaging modality, in particular, for pelvic floor dysfunction with the leading symptom of impaired bowel evacuation.
  Due to the multifactorial etiology of pelvic floor dysfunction, mainly involving several compartments and often combined disorders, dynamic visualization of all pelvic organs is paramount.
  Changes in the middle “gynecological” compartment and in the anterior, “urological” compartment of the pelvic floor cannot be visualized. In the past, this was only possible indirectly through additional contrast enhancement of the accessible organs by colpocystorectography. However, radiation exposure and the psychological stress should not be overlooked.
• Dynamic pelvic floor MRI
  Compared with standard defecography, dynamic pelvic floor MRI can provide a complete picture of the pelvic floor and its organs, since the anterior, middle and posterior compartments and any concomitant enteroceles can be visualized in one study and without radiation exposure. At the same time, dynamic pelvic floor MRI can depict the anatomical position of all pelvic organs during breathing, straining and pinching phases, both as single images and video sequences of great informational value.
  In general, dynamic pelvic MRI (as MR defecography) offers the, mainly female, patients the benefit over standard defecography of being able to visualize all compartments and organ systems with enhanced patient comfort.
  The main benefit is the lack of radiation exposure. Having the patient seated or recumbent does not change the study outcome. However, the morphological significance of dynamic MRI studies has not yet been fully clarified since normal and pathological findings overlap.
• Endosonography (endoscopic ultrasound) is helpful if a sphincter defect is suspected.
• Additional function testing, such as electromyography and measurement of the nerve conduction velocity, is reserved for exceptional cases.

Colonoscopy
Preoperative standard modality to study colorectal topography and rule out other pathologies.

• A simple enema on the evening before surgery and on the morning of the day of the operation is adequate for bowel preparation.
• Optional orthograde colonic lavage

In the operating room (OR):

• Perioperative antibiotic prophylaxis as single shot 1.5-3.0 g iv. ampicillin/sulbactam
• Foley catheter

General risks

• Bleeding
• Secondary bleeding
• Necessity of blood transfusions with corresponding transfusion risks
• Thromboembolism
• Wound infection
• Abscess
• Injury to adjacent organs/structures (internal female genitalia, urinary bladder)

Special risks

• Abscess formation
• Changes in stool habits
• Recurrent prolapse
• Persistent fecal or residual incontinence
• Supraanal rectal stenosis