Lack of efficacy of an intradural somatic-to-autonomic nerve anastomosis (Xiao procedure) for bladder control in children with myelomeningocele and lipomyelomeningocele: results of a prospective, randomized, double-blind study

Clinical Anatomy of the Sacral Nerve Roots and Its Relevance to Their Reconstruction After Sacrectomy

BACKGROUND AND OBJECTIVES

En bloc sacrectomy is associated with sacral root transection causing loss of urinary bladder, rectum, and sexual function. The aim of the study was to determine the position of the pudendal branches (sensorimotor) and pelvic splanchnic nerves (parasympathetic) on the sacral roots relative to the sacrum, and the minimal and maximal defects in the sacral roots that can be reconstructed by grafting after various types of sacrectomy.

METHODS

Five cadaveric pelves were dissected bilaterally. The lengths and widths of the S1-S4 roots and their branches were measured. Then, the minimal and maximal defects between the proximal and distal stumps of the sacrificed roots were measured following 3 models of sacrectomy (below S2, below S1, and total sacrectomy).

RESULTS

The mean distance of the splanchnic nerves from the S2 and S3 anterior sacral foramina was 17.7 ± 7.3 and 23.6 ± 11.1 mm, respectively, and the mean distance of the pudendal S2 and S3 branches was 36.8 ± 13.7 and 30.2 ± 10.8 mm, respectively. The mean widths of the S2 and S3 roots were 9.3 ± 1.9 and 5.4 ± 1.2 mm, respectively. The mean maximal defects in S2 and S3 roots after various types of sacrectomies were between 61.8 ± 16.3 and 100.7 ± 14.3 mm and between 62.7 ± 20.2 and 84.7 ± 25.1 mm, respectively. There were no statistically significant differences between sides or sexes for all obtained measurements.

CONCLUSION

The reconstruction of the S2-S3 roots is anatomically feasible after partial or total sacrectomies in which the resection of the soft tissue does not extend further than approximately 1.5 to 2 cm ventrally from the sacrum.

Pragmatism in Pediatric Neurosurgery: More Than a Pipe Dream? A Systematic Literature Review and Analysis

BACKGROUND

Classic randomized controlled trials (RCTs) form the cornerstone for medical guidelines and protocols. However, in neurosurgery, RCTs are not always applicable to everyday clinical practice. Pragmatic controlled trials aim to incorporate real-life data with the preservation of the methodologic quality. This study is a systematic literature review of all pediatric neurosurgical RCTs published between 2000 and 2020 and an analysis of their pragmatism.

METHODS

An electronic database search was performed in PubMed, EMBASE, and the Cochrane Library to identify all relevant trials. Pragmatism was evaluated retrospectively on 9 domains: eligibility, recruitment, setting, organization, flexibility (delivery and adherence), follow-up, primary outcome, and primary analysis.

RESULTS

Of the 1862 studies included, 15 met the inclusion criteria. On average, studies scored between equally pragmatic/explanatory and rather pragmatic (M = 3.59, standard deviation [SD] = 0.56). Lowest ratings were seen for setting (M = 2.80, SD = 1.66) and eligibility (M = 3.20, SD = 1.66). Highest scores of pragmatism were given to analysis (M = 4.67, SD = 0.82) and intervention organization (M = 4.60, SD = 1.06). There was no significant difference between studies based on number of patients included, main subject, or publication year.

CONCLUSIONS

Pediatric neurosurgical RCTs scored reasonably well on overall pragmatism. In the future, there will be a greater need for pragmatic controlled trials in pediatric neurosurgery to bridge the divide between real-life data and reliable methodological quality. There is an opportunity to develop further applications of pragmatism tailored to surgical interventions.

The TGF-β1 pathway is early involved in neurogenic bladder fibrosis of juvenile rats

BACKGROUND

This study investigated whole neurogenic bladder's progression changes, as well as the expression of TGF-β1 fibrosis pathway-related proteins in bilateral spinal nerve-amputated juvenile rats.

METHODS

Sixty-four 8-week-old rats (32 bilateral L6 + S1 spinal nerve amputated and 32 sham operated) were selected. Cystometry was performed. General assessments, Masson, Sirius red, immunohistochemical staining, and western blotting of fibrosis and TGF-β1 pathway-related proteins were conducted using bladder tissues.

RESULTS

Cystometry results showed that the basal intravesical pressures and bladder capacities in nerve-amputated rats were significantly higher than those in sham-operated ones. Compared to the sham-operated groups, the bladder size and wall thickness in the nerve-amputated groups increased initially but then decreased over time. However, bladder weight continuously increased over time. Disintegration, thickening, and hypertrophy of the bladder wall were found over time in the amputated rats. Moreover, there was a significant increase in collagen III, and the ratio of collagen III/I was higher in amputated rats (P < 0.01). Finally, the expression of TGF-β1, TGF-βRI, Smad2, and collagen III and I increased in amputated bladder tissues, while Smad6 decreased over time.

CONCLUSIONS

The main clinical features of pediatric neurogenic bladder (PNB) were detrusor paralysis and continuous intravesical pressure. Biological molecular findings are earlier than the pathophysiological findings. Therefore, early preventing bladder fibrosis by targeting TGF-β1/Smad pathway-related proteins once knowing the PNB diagnosis might be an alternative treatment for PNB.

IMPACT

The study found that the main clinical features of PNB were detrusor paralysis, continuous intravesical pressure, and increased TGF-beta/Smad signal proteins over time. The study makes contributions to the literature because it suggests biological molecular findings are earlier than the pathophysiological findings by various staining in PNB. The study investigated whole neurogenic bladder's progression changes, as well as the expression of TGF-β1 fibrosis pathway-related proteins in the spinal nerve-injured PNB juvenile rat models, which suggests that early prevention of bladder fibrosis by targeting TGF-β1/Smad pathway-related proteins once knowing the PNB diagnosis might be an alternative treatment for pediatric neurogenic bladder.

Lumbar to sacral root rerouting to restore bladder function in a feline spinal cord injury model: Urodynamic and retrograde nerve tracing results from a pilot study

AIMS

Lumbar to sacral rerouting surgery can potentially allow voiding via a skin-central nervous system-bladder reflex pathway. Here, we assessed if this surgery was effective in treating neurogenic bladder dysfunction/sphincter in felines.

METHODS

Eight cats underwent spinal cord transection (SCT) at thoracic level 10/11. Unilateral L7 to S1 ventral root anastomosis was performed 1 month later in six cats. Two cats served as transection-only controls. Electrical and manual stimulation of L6-S1 dermatomes, and urodynamics were performed at 3, 5, 7, and 9/10 months post transection. At 9/10 months, cats were also evaluated by direct electrophysiological testing of anastomosed roots with urodynamics, then tissue collection and examination of the root anastomosis site and lumbosacral cord ventral horns for cells retrogradely labeled from tracer dye injected 2 weeks earlier into the bladder wall.

RESULTS

At 9/10 months, four of six rerouted cats exhibited increased detrusor pressure provoked by cutaneous stimulation, one cat bilaterally. Two cats presented with a voiding stream after ipsilateral cutaneous stimulation at 7 and 9 months. All six rerouted animals showed regrowth of axons from the L7 ventral horn to the bladder, although some aberrant axonal regrowth was also observed.

CONCLUSION

L7 to S1 ventral root rerouting below the level of SCT showed successful axonal regrowth to the bladder from the L7 spinal cord segment in all rerouted animals, and induced increased detrusor pressure response to cutaneous stimulation in a subset. This feasibility study paves the way for future animal studies for bladder reinnervation.