Perioperative management - STARR — Stapled TransAnal Rectal Resection

Stapled transanal rectal resection of the rectum (STARR) has become a surgical option in the treatment of obstructed defecation syndrome (ODS - also known as outlet obstruction). The STARR technique is intended to reduce rectal intussusception (=internal rectal prolapse) and/or rectocele as the morphological cause of outlet obstruction by combining transversal tightening of the rectovaginal septum by the stapled suture line with annular rectal mucosal resection.

Defecation disorder in the sense of outlet obstruction is a form of chronic constipation. It is a high-incident pathology that significantly restricts the quality of life of many people.

The causes are many and varied: On the one hand, stenoses in the anal and lower rectum may impair defecation. On the other hand, there will be dysfunctions of the pelvic floor itself.

Pelvic floor dyssynergia, i.e. paradoxical contraction of the puborectal muscle and anal sphincter during defecation, and anismus (involuntary, uncontrollable, spontaneous contraction of the pelvic floor muscles) are regarded to be the most important functional causes.

Frequent morphological abnormalities of the pelvic floor in defecation disorders are rectoceles, intussusception of the distal rectum and enteroceles/ sigmoidoceles (prolapse of loops of the small intestine or sigmoid into the lower Douglas pouch, especially after hysterectomy and as part of a general prolapse problem). Mechanical occlusion is attributed to rectocele and intussusception.

Enterocele/sigmoidocele and genital prolapse are possible extrarectal causes. Stool retention in the pendulous sigmoid (cul de sac) and compression of the rectum by this segment of the colon may result in a defecation disorder.

The clinical significance of the various morphological abnormalities has not yet been fully understood.

Since correction of morphological abnormalities does not necessarily improve function, surgical intervention should be considered only after conservative treatment has failed or been ineffective.

• Slow-transit constipation with hypo-/aganglionosis
• Functional outlet obstruction, e.g. paradoxical levator ani syndrome, anismus
• Sigmoid pathology (diverticulitis, pronounced sigmoidocele) → relative contraindication, here, laparoscopic sigmoid resection with anterior or posterior rectopexy should be performed.
• Anal fissure
• Anal stenosis
• Fistulas
• Inflammation in the rectum, e.g. IBD, proctitis
• Rectal malignancies
• Previous operations in the lesser pelvis, especially rectal resection
• Foreign material from previous procedures (e.g. mesh implants after rectopexy or previous gynecological surgery)

Diagnostic work-up of the pelvic floor is preceded by basic proctologic work-up ruling out pathologic changes such as chronic anal fissure, possibly with consecutive anal stenosis, prolapsing hemorrhoidal disease, anal prolapse, manifest rectal prolapse.

Stenosis of the colon and rectum by malignancies or chronic IBD must, of course, be assessed as part of the primary diagnostic examination. Therefore, total colonoscopy is mandatory in all patients with defecation disorders. After ruling out these changes, to be treated as top priority, the patient's medical history provides the most important information regarding the present symptoms.

Medical history with use of standardized questionnaires to identify constipation or incontinence. Typical symptoms include delayed and incomplete defecation, a feeling of blockage, excessive straining during defecation, digital assistance with defecation, stool spotting (often assessed as soft stool incontinence), use of laxatives, and anal bleeding.

In order to differentiate it from irritable bowel syndrome with elements of constipation, history taking should ask for additional symptoms, in particular abdominal pain and meteorism. Urological and gynecological complaints should also be assessed. Together they are often the sign of complex organ prolapse.

Clinical proctological evaluation with inspection, rectal-digital examination, proctoscopy and rectoscopy, complete colonoscopy, CT of the abdomen in pronounced pain symptoms during defecation as indirect sign of sigmoid pathology, functional diagnostic work-up. The most important study is radiological imaging of the process of defecation.

Conventional defecography:

Conventional defecography allows assessment not only of rectal prolapse but also of abnormalities such as rectocele, intussusception and sigmoidocele. Since defecography diagnoses functional as well as morphological changes of the pelvic floor including the rectosigmoid - in case of oral contrast agents also enteroceles - this modality yields deep insight, especially in pelvic floor failure with the leading symptom " defecation disorder".
Due to the multifactorial etiology of pelvic floor failure, which usually involves several compartments and often combined disorders, dynamic imaging of all pelvic organs is crucial.

Changes in the central "gynecological" compartment and in the anterior "urological" compartment of the pelvic floor cannot be imaged. In the past, this was only possible indirectly by additional contrast of the accessible organs by means of colpocystorectography, although the exposure to radiation and the psychological stress caused by the examination itself cannot be neglected.

Dynamic pelvic floor MRI:

In comparison to conventional defecography, dynamic MRI of the pelvic floor offers the opportunity to ensure total imaging of the pelvic floor and its organs, since the anterior, central and posterior compartments, as well as enteroceles, may be imaged without radiation exposure in a single scan.

Studies with the patient sitting or recumbent do not result in different findings. In general, however, the relevance of image morphology in dynamic MRI studies has not yet been fully established, as normal and pathological findings overlap.

Ultrasonography as dynamic perineal or endorectal ultrasound:

Recommended as non-invasive study, especially if dynamic MRI is not available. This rather simple study can provide additional information on pelvic floor pathologies such as enterocele, rectocele and cystocele.

Colon transit time:

A transit time study according to Hinton is indicated only if the patient's medical history suggests a transit disorder with significantly less frequent defecation.

A simple enema the evening before the operation and on the morning of the day of surgery will suffice as intestinal preparation.

Perioperative prophylactic intravenous antibiotics (and in special cases possibly also as short-term therapy) with a second-generation cephalosporin and metronidazole or ampicillin/sulbactam.

• The relatively high complication rate must be considered when setting the indication and informing the patient.
• Secondary bleeding
• Septic complications
• Fecal urgency
• Urinary retention
• Suture line failure
• Fecal incontinence
• Recurrent intussusception and/or obstructive defecation syndrome
• Rectovaginal fistula