Bladder Urethral Dysfunction after Abdominoperineal Resection of the Rectum for Anorectal Cancer

Contemporary concepts in the aetiopathogenesis of detrusor underactivity

Detrusor underactivity (DUA) is a poorly understood, yet common, bladder dysfunction, referred to as underactive bladder, which is observed in both men and women undergoing urodynamic studies. Despite its prevalence, no effective therapeutic approaches exist for DUA. Exactly how the contractile function of the detrusor muscle changes with ageing is unclear. Data from physiological studies in animal and human bladders are contradictory, as are the results of the limited number of clinical studies assessing changes in urodynamic parameters with ageing. The prevalence of DUA in different patient groups suggests that multiple aetiologies are involved in DUA pathogenesis. Traditional concepts focused on either efferent innervation or myogenic dysfunction. By contrast, contemporary views emphasize the importance of the neural control mechanisms, particularly the afferent system, which can fail to potentiate detrusor contraction, leading to premature termination of the voiding reflex. In conclusion, the contemporary understanding of the aetiology and pathophysiology of DUA is limited. Further elucidation of the underlying mechanisms is needed to enable the development of new and effective treatment approaches.

Predictors of postoperative urinary retention after colorectal surgery

BACKGROUND

National quality initiatives have mandated the earlier removal of urinary catheters after surgery to decrease urinary tract infection rates. A potential unintended consequence is an increased postoperative urinary retention rate.

OBJECTIVE

The aim of this study was to determine the incidence and risk factors for postoperative urinary retention after colorectal surgery.

DESIGN

This was a prospective observational study.

SETTINGS

A colorectal unit within a single institution was the setting for this study.

PATIENTS

Adults undergoing elective colorectal operations were included.

INTERVENTIONS

Urinary catheters were removed on postoperative day 1 for patients undergoing abdominal operations, and on day 3 for patients undergoing pelvic operations. Postvoid residual and retention volumes were measured.

MAIN OUTCOME MEASURES

The primary outcomes measured were urinary retention and urinary tract infection.

RESULTS

The overall urinary retention rate was 22.4% (22.8% in the abdominal group, 21.9% in the pelvic group) and was associated with longer operative time and increased perioperative fluid administration. Mean operative time for those with retention was 2.8 hours and, for those without retention, the mean operative time 2.2 hours (abdominal group 2 hours vs 1.4 hours, pelvic group 3.9 hours vs 3.1 hours, p ≤ 0.02). Patients with retention received a mean of 2.7L during the operation, whereas patients without retention received 1.8L (abdominal group 1.9L vs 1.4L, pelvic group 3.6L vs 2.2L, p < 0.01). In the abdominal group, patients with and without retention also received different fluid volumes on postoperative days 1 (2.2L vs 1.7L, p = 0.004) and 2 (1.6L vs 1L, p = 0.05). Laparoscopic abdominal group had a 40% retention rate in comparison with 12% in the open abdominal group (p = 0.004). Age, sex, preoperative radiation therapy, preoperative prostatism, preoperative diagnosis, and level of anastomosis were not associated with retention. The urinary tract infection rate was 4.9%.

LIMITATION

The lack of documentation of preoperative urinary function was a limitation of this study.

CONCLUSIONS

The practice of earlier urinary catheter removal must be balanced with operative time and fluid volume to avoid high urinary retention rates. Also important is increased vigilance for the early detection of retention.

Methylene blue staining for nerve-sparing operative procedures: an animal model

OBJECTIVES

To evaluate methylene blue fiber staining as a method of nerve fiber identification in an animal model, because the maintenance of organ function after surgery depends on exact intraoperative identification of the relevant nerve fibers.

METHODS

Brindley electrodes were implanted bilaterally at S3 for sacral anterior root stimulation in six minipigs. For reference, stimulation-induced detrusor contractions were recorded urodynamically. After exposure of the ureterovesical junction on both sides, a 2:8 methylene blue solution was applied to the right side; the left side remained untreated. Bilateral dissection of the ureter from the surrounding tissue for a distance of 4 cm proximal to the ureterovesical junction was performed. The methylene blue-stained nerve fibers on the right side were spared; no particular attention was paid to the nerves on the left. Again, sacral anterior root stimulation-induced detrusor contractions were monitored urodynamically on both sides. Then, the identified nerve fibers on the right were cut intentionally, and the detrusor pressure was recorded again under stimulation. Finally, the dissected nerve structures were evaluated histologically.

RESULTS

The reference bladder pressures after unilateral stimulation on the left side before ureter dissection showed a mean detrusor pressure (Pdet) of 19 cm H2O. On the right side, the Pdet was 18 cm H2O. After preparation on both sides, a mean Pdet of 3 cm H2O was recorded after left side stimulation, and a Pdet of 17 cm H2O after right side stimulation. When the stained nerve fibers on the right side were cut, no bladder contractions could be induced. The histomorphology of the stained and dissected structures revealed multiple autonomous nerve fibers and small vessels in connective tissue.

CONCLUSIONS

The identification of minute nerve bundles is a tedious and difficult task. The results from our animal model demonstrated that supravital staining of autonomous nerve fibers with methylene blue is a simple and reliable method of identification.

Risk of detrusor denervation in antireflux surgery demonstrated in a neurophysiological animal model

PURPOSE

Earlier anatomical studies have shown a close connection between the ureterovesical junction and detrusor innervation. It prompted us to develop an animal model to demonstrate the risk of partial or complete impairment of this neuronal connection during antireflux surgery.

MATERIALS AND METHODS

Six female Göttinger minipigs were anesthetized and laminectomized. After placement of the S3 sacral nerves into separate electrode compartments of a modified Brindley electrode the lower urinary tract was exposed by an abdominal midline incision. After bladder instillation with 150 ml NaCl 1 bilateral and 2 unilateral stimulations (left and right sides) were performed and intravesical pressure was recorded urodynamically. The left ureter was then prepared circularly in 3 steps 10, 5 and 1 cm, respectively, proximal to the ureterovesical junction. After each preparation step bilateral and unilateral stimulation was repeated. Results were recorded urodynamically and video documented.

RESULTS

Bilateral stimulation before preparation of the left ureter led to a concentric detrusor contraction with an average maximum detrusor pressure of 51 cm H(2)O. Unilateral stimulation resulted in ipsilateralbound bladder tilting with an intravesical pressure of 18 and 19 cm H(2)O on the right and left sides, respectively. After preparation of the left ureter 10, 5 and 1 cm from the ureterovesical junction a maximum detrusor pressure of 17, 10 and 1 cm H(2)O was documented, respectively. While there was almost no stimulation response of the bladder after the last preparation step at 1 cm on the left ureter, the initial bladder pressure of 18 cm H(2)O could be reproduced under stimulation on the right side.

CONCLUSIONS

Analogous to human cadaver studies, we were able to prove neurophysiologically strictly unilateral detrusor innervation, drawing from the pelvic plexus dorsomedial to the ureterovesical junction into the bladder. Preparation of this ureterovesical junction during antireflex surgery, coagulating measures in this area or the affixation of anchor sutures after a Vest suture involves the risk of unilateral or bilateral detrusor decentralization.

Avoiding long-term disturbance to bladder and sexual function in pelvic surgery, particularly with rectal cancer

Urinary and sexual dysfunction are common problems after rectal cancer surgery, and the likely cause is damage to the pelvic autonomic nerves during surgery. In recent years, attention has been focused on preserving the autonomic nerves through a technique which is usually combined with total mesorectal excision or radical pelvic lymphadenectomy. The autonomic nerves consist of the paired sympathetic hypogastric nerve, sacral splanchnic nerves, and the pelvic autonomic nerve plexus. We will demonstrate the anatomy of the pelvic autonomic nerves and the relation of these nerves to the mesorectal fascial planes, and review the medical literature on sexual and urinary dysfunction after rectal cancer surgery with and without autonomic nerve preservation.

Bladder and sexual dysfunction after mesorectal excision for rectal cancer

BACKGROUND

Urinary and sexual dysfunction are recognized complications of rectal excision for cancer. The aim of this study was to examine the frequency of such complications after mesorectal excision, shortly after this method was introduced.

METHODS

Spontaneous flowmetry, residual volume of urine measurement and urodynamic examination, including cystometry and simultaneous detrusor pressure and urinary flow recording, was carried out before and 3 months after curative rectal excision. Urinary symptoms and sexual function were evaluated by means of questionnaires before and after operation. Each patient served as his or her own control.

RESULTS

Forty-nine consecutive patients, 39 of whom had a total mesorectal excision (TME) and ten a partial mesorectal excision, were examined before surgery and 35 again after operation. In two patients, a weak detrusor was detected before operation. Two patients developed signs of bladder denervation after operation. Transitory moderate urinary incontinence appeared in four other women. Six of 24 men reported some reduction in erectile function and one became impotent. Two men reported retrograde ejaculation. All the complications were seen in the TME group.

CONCLUSION

Mesorectal excision for rectal cancer resulted in a low frequency of serious bladder and sexual dysfunction.

Quality of life after treatment for rectal cancer

BACKGROUND

The studies on patient-reported symptoms and quality of life following the treatment of rectal cancer were evaluated; guidelines for future quality of life studies in this field are proposed.

METHODS

Relevant papers in the English language were identified via Medline from January 1970 to November 1997, supplemented by a manual search for similar articles.

RESULTS

Patients suffer various short- and long-term complications after treatment of rectal cancer, although the reported prevalence of such problems varies from study to study. Recent prospective studies have shown that, despite these problems, global quality of life scores as measured by generic questionnaires improve after surgery.

CONCLUSION

The methodological shortcomings of previous work must be rectified if quality of life studies are to have relevance in patient management.

Micturitional dysfunction after anterior resection for rectal cancer. Rehabilitative treatment

A clinical study was made of 21 patients (13 men and eight women) who had undergone anterior resection of the rectum for cancer at the National Tumour Institute of Milan between April 1984 and April 1985. After surgery, 13 patients (including three men with benign prostatic hypertrophy) showed voiding dysfunctions (hesitancy, dysuria, and weak stream) and bladder areflexia. Two of them also had positive Lapides' tests. An early rehabilitative treatment was started after surgery and the entire group was thoroughly reexamined one year later. Only the two patients with positive Lapides' tests still had bladder areflexia with residual urine greater than 100 ml. One of them also had a urinary tract infection. None of them showed decreased renal function.