Comparing short-term outcomes between conus medullaris and cauda equina surgical techniques of selective dorsal rhizotomy

[Invasive neurostimulation in neuro-urology: state of the art]

Modulation or stimulation of the nerves supplying the lower urinary tract is a possible treatment option for dysfunction of the lower urinary tract, pelvic floor and rectum if conservative or minimally invasive treatment approaches fail. This overview shows the possibilities and limitations of sacral neuromodulation, sacral deafferentation with sacral anterior root stimulation and conus deafferentation.Sacral neuromodulation (SNM) is a procedure for the treatment of refractory pelvic floor dysfunction of various origins (idiopathic, neurogenic or post-operative), such as overactive bladder, non-obstructive retention and faecal incontinence. A particular advantage of SNM is the possibility of prior test stimulation with a high prognostic value. The procedure is minimally invasive, reversible and associated with relatively low morbidity rates.Following the introduction of MRI-compatible SNM systems, there has been renewed interest in the treatment of neurogenic bladder dysfunction. A recent meta-analysis reports similar success rates as in the idiopathic patient population.Sacral deafferentation with implantation of a sacral anterior root stimulator (SARS/SDAF) is an excellent therapeutic option for patients with spinal cord injury, which can significantly improve the quality of life of those affected and, in addition to treating neurogenic lower urinary tract dysfunction, can also have a positive effect on neurogenic bowel dysfunction, neurogenic sexual dysfunction or autonomic dysreflexia. If conservative or minimally invasive treatment fails, it is crucial for the success of this procedure to consider SDAF/SARS at an early stage in order to avoid irreversible organic damage.Conus deafferentation (KDAF) is a less invasive surgical treatment option for patients with spinal cord injury for whom sacral deafferentation would be indicated but who would not benefit from the simultaneous implantation of a sacral anterior root stimulator. In principle, these patients also have the option of being subsequently treated with an extradural implant and thus utilising the advantages of anterior root stimulation. Indications for KDAF are autonomic dysreflexia, therapy-refractory detrusor overactivity, recurrent urinary tract infections, urinary incontinence and spasticity triggered by detrusor overactivity. With KDAF, we have a safe and efficient procedure with great potential for improving the spectrum of paraplegiological and neuro-urological treatment.

Postoperative pain and pain management following selective dorsal rhizotomy

BACKGROUND

Selective dorsal rhizotomy (SDR) is a neurosurgical procedure that reduces lower limb spasticity, performed in some children with spastic diplegic cerebral palsy. Effective pain management after SDR is essential for early rehabilitation. This study aimed to describe the anaesthetic and early pain management, pain and adverse events in children following SDR.

METHODS

This was a retrospective cohort study. Participants were all children who underwent SDR at a single Australian tertiary hospital between 2010 and 2020. Electronic medical records of all children identified were reviewed. Data collected included demographic and clinical data (pain scores, key clinical outcomes, adverse events and side effects) and medications used during anaesthesia and postoperative recovery.

RESULTS

22 children (n=8, 36% female) had SDR. The mean (SD) age at surgery was 6 years and 6 months (1 year and 4 months). Common intraoperative medications used were remifentanil (100%), ketamine (95%), paracetamol (91%) and sevoflurane (86%). Postoperatively, all children were prescribed opioid nurse-controlled analgesia (morphine, 36%; fentanyl, 36%; and oxycodone, 18%) and concomitant ketamine infusion. Opioid doses were maximal on the day after surgery. The mean (SD) daily average pain score (Wong-Baker FACES scale) on the day after surgery was 1.4 (0.9), decreasing to 1.0 (0.5) on postoperative day 6 (POD6). Children first attended the physiotherapy gym on median day 7 (POD8, range 7-8). Most children experienced mild side effects or adverse events that were managed conservatively. Common side effects included constipation (n=19), nausea and vomiting (n=18), and pruritus (n=14). No patient required return to theatre, ICU admission or prolonged inpatient stay.

CONCLUSIONS

Most children achieve good pain management following SDR with opioid and ketamine infusions. Adverse events, while common, are typically mild and managed with medication or therapy. This information can be used as a baseline to improve postoperative care and to support families' understanding of SDR before surgery.

Spinal cord tethering after selective dorsal rhizotomy below the conus medullaris

BACKGROUND

Two techniques for selective dorsal rhizotomy (SDR) involve stimulating and sectioning nerve rootlets either below the conus medullaris or above the entrances to their respective dural root sleeves. In general, both techniques lead to sustained improvements in lower extremity spasticity with low complication rates. To our knowledge, spinal cord tethering has not been previously reported as a complication of SDR using either technique.

METHODS

We review the presentation, treatment, and outcome of two patients who developed symptomatic spinal cord tethering after SDR below the conus.

RESULTS

A 4-year-old male and a 6-year-old female each with a history of spastic diparetic cerebral palsy underwent L1-L2 osteoplastic laminectomy and SDR below the conus. Both surgeries went well with no known complications. Both patients initially did well, with marked improvement in their tone and gait. There were no significant immediate postoperative bowel or bladder problems. The male patient presented 10 months after surgery with new-onset urinary incontinence. A urological evaluation was performed but no imaging was performed. He re-presented 8 months later with worsened urinary incontinence, new fecal incontinence, and worsened gait. An MRI showed signs of tethering, including a holocord syrinx. He underwent two untethering surgeries as well syrinx fenestration, and although his gait improved, it remained worse than it had been several months after surgery. The incontinence did not improve. The second patient also developed urinary incontinence a year after SDR. Due to our experience with the first patient, we obtained an MRI immediately and found evidence of tethering. She underwent untethering and her incontinence improved.

CONCLUSION

We report two cases of spinal cord tethering after SDR below the conus, a previously unreported complication. It is important to realize that this complication can occur after SDR.

Multidimensional Outcomes of Selective Dorsal Rhizotomy for Children With Spastic Cerebral Palsy: Single-Level Laminectomy vs Multiple-Level Laminotomy Techniques

BACKGROUND

Selective dorsal rhizotomy (SDR) reduces lower limb spasticity, improves gait patterns, and restores normal physical and social activity in children with spastic cerebral palsy. Single-level laminectomy (SLL) and multiple-level laminotomy (MLL) are 2 surgical approaches for SDR with limited clinical data comparing their postoperative outcomes.

OBJECTIVE

To compare the differences in multidimensional outcomes after SDR between SLL and MLL for children with spastic cerebral palsy.

METHODS

We retrospectively reviewed children who underwent SDR in our hospital from 1997 to 2016. The multidimensional outcomes in spasticity, joint range of motions, gait kinetics, gross motor activities, functional outcomes, and urological outcomes were assessed 1 year postoperatively. Hip dysplasia and scoliosis rate were compared as long-term outcomes.

RESULTS

Sixty children underwent SDR, including 34 SLL patients and 26 MLL patients. Most improvements in multidimensional outcomes were comparable between SLL and MLL. Patients in the SLL group had larger improvements in ankle dorsiflexion in the midstance phase (SLL 7.59° ± 11.48° vs MLL 0.29° ± 11.30°, P = .027). The rate of scoliosis was similar between the 2 surgical approaches (SLL 12.1% vs MLL 15.4%, P = .722).

CONCLUSION

SDR for children with spastic cerebral palsy could provide physical, functional, and urological improvements. SLL achieved a higher degree of improvement in ankle dorsiflexion in the midstance phase. The rate of scoliosis was not significantly increased by multiple-level laminotomy.

Short-term causal effects of common treatments in ambulatory children and young adults with cerebral palsy: three machine learning estimates

Orthopedic and neurological impairments (e.g., muscle contractures, spasticity) are often treated in children and young adults with cerebral palsy (CP). Due to challenges arising from combinatorics, research funding priorities, and medical practicalities, and despite extensive study, the evidence base is weak. Our goal was to estimate the short-term effectiveness of 13 common orthopedic and neurological treatments at four different levels of outcome in children and young adults diagnosed with CP. The outcome levels considered were body structures, specific gait kinematic deviations, overall gait kinematic deviations, and functional mobility. We used three well-establish causal inference approaches (direct matching, virtual twins, and Bayesian causal forests) and a large clinical gait analysis database to estimate the average treatment effect on the treated (ATT). We then examined the effectiveness across treatments, methods, and outcome levels. The dataset consisted of 2851 limbs from 933 individuals (some individuals underwent multiple treatment episodes). Current treatments have medium effects on body structures, but modest to minimal effects on gait and functional mobility. The median ATT of 13 common treatments in children and young adults with CP, measured as Cohen's D, bordered on medium at the body structures level (median [IQR] = 0.42 [0.05, 0.60]) and became smaller as we moved along the causal chain through specific kinematic deviations (0.21 [0.01, 0.33]), overall kinematic deviations (0.09 [0.03, 0.19]), and functional mobility (-0.01 [-0.06, 0.13]). Further work is needed to understand the source of heterogeneous treatment effects, which are large in this patient population. Replication or refutation of these findings by other centers will be valuable to establish the generalizability of these results and for benchmarking of best practices.