Anorectal function after major resections of the sacrum with bilateral or unilateral sacrifice of sacral nerves

Abstract

The anorectal function in 3 patients with bilateral and 4 patients with unilateral well-defined loss of sacral nerves after radical tumour excision was studied by clinical examination and by simultaneous registration of the following variables: volume and pressure in the rectum, pressure in the internal anal sphincter area and myoelectrical activity in the external anal sphincter. The patients with bilateral loss of sacral nerves had serious impairment of function. Constipation was their only safeguard against incontinence. The preservation of the first and second sacral nerves bilaterally was not sufficient for discrimination between different qualities of rectal contents passing the anal canal. The sensation of rectal distension was also impaired. The reflex pattern of the internal anal sphincter was, however, intact. The external anal sphincter displayed a weak spontaneous myoelectrical activity in the patients who had at least one second sacral nerve intact, and a weak increase of the activity could be induced voluntarily. The normal transient increase of myoelectrical discharge from the external anal sphincter in response to rectal distension could not, however, be elicited. In patients with total unilateral loss of the sacral nerves no significant impairment of anorectal function was noted. Total one-sided denervation implied deficient sensibility of the anal canal unilaterally, but no disturbance of sphincter function as judged from the reflex response of the internal and external anal sphincters to rectal distension.

How Does the Level of Nerve Root Resection in En Bloc Sacrectomy Influence Patient-Reported Outcomes?

“…A recent study, using the same questionnaire, showed comparable results for physical health, but not for mental health [22]. Several studies done from a physiological point of view show that the sparing of S3 is necessary for normal function of bowel, bladder function, and sexual function [5,8,9,11,25]. This might explain the impact on physical and mental health when S3 is sacrificed.…”

“…These effects have been studied from a physiological point of view. For example, quantitative changes in bowel and bladder function using manometry and cystometry have been reported [8,20]. Other studies based their results on a retrospective review of pre-and postoperative medical records and use dichotomous outcomes [19,25].…”

How Does the Level of Sacral Resection for Primary Malignant Bone Tumors Affect Physical and Mental Health, Pain, Mobility, Incontinence, and Sexual Function?

“…However, the sacral nerves control anal sphincter, bladder, and sexual function and their removal can lead to functional loss and presumably a decreased quality of life. Previous studies have demonstrated the functional role of the sacral nerves from a physiologic perspective [7,[9][10][11]19]. Other studies have described the symptoms of bowel and bladder dysfunction as reported to the treating clinician [12,14,21].…”

“…Malignant tumors of the sacrum often invade the sacral nerve roots and they are therefore necessarily sacrificed during definitive resection. Several studies have documented the deleterious effects of sacral nerve root resection on the normal physiology of bowel, bladder, and sexual function [7,[9][10][11]19]. Other studies have documented the clinical effects of sacral tumor resection as reported in patients' medical records [3-5, 12, 14].…”

“…Other studies have documented the clinical effects of sacral tumor resection as reported in patients' medical records [3-5, 12, 14]. The level of sacral nerve root resection has been shown to be important and sparing of the S3 nerve root has been reported to allow some bowel, bladder, and sexual function [7,[9][10][11][12]14]. Because the level of nerve root resection is dictated by the location of the tumor if one is attempting to achieve negative margins, patients and clinicians must weigh the improved local control and survival associated with a particular surgical approach against the loss of bowel, bladder, and sexual function also associated with that surgery.…”