Peripheral nerve graft architecture affects regeneration

The primary goal in repairing a peripheral nerve lesion is to guide the outgrowing axon back to its original target organ, which can be done by bridging the defect with an autograft or, more experimentally, a synthetic nerve graft. In this thesis an overview is presented of the evaluation methods that are currently used to assess peripheral nerve regeneration and their expediency is discussed. An in vitro electrophysiological evaluation method that charts the electrophysiological properties of the myelinated Aα- and Aβ-nerve fibres was introduced, and it was demonstrated that small differences between grafted nerves could be discriminated. Moreover, the electrophysiological data could be correlated to the morphometrical data, that was likewise broken up into Aα- and Aβ-components. This correlation especially provided new insight in the changes that occur in regenerating nerve fibres. After applying a panel of evaluation methods it was demonstrated that the presence of pores in and biodegradability of synthetic nerve grafts are beneficial to regeneration, evidenced mainly by preferable values of the electrophysiological parameters. Finally the changes that occurred in reinnervated muscles helped to gain insight into the preferential architecture of a synthetic nerve graft.​​​​​​​UBL - phd migration 201

Adhesion and proliferation of human schwann cells on adhesive coatings

Attachment to and proliferation on the substrate are deemed important considerations when Schwann cells (SCs) are to be seeded in synthetic nerve grafts. Attachment is a prerequisite for the SCs to survive and fast proliferation will yield large numbers of SCs in a short time, which appears promising for stimulation of peripheral nerve regeneration. The aim of the present study was to compare the adhesion and proliferation of human Schwann cells (HSCs) on different substrates. The following were selected for their suitability as an internal coating of synthetic nerve grafts; the extracellular matrix proteins fibronectin, laminin and collagen type I and the poly-electrolytes poly( -lysine) (PDL) and poly(ethylene-imine) (PEI). On all coatings, attachment of HSCs was satisfactory and comparable, indicating that this factor is not a major consideration in choosing a suitable coating.\ud \ud Proliferation was best on fibronectin, laminin and PDL, and worst on collagen type I and PEI. Since nerve regeneration is enhanced by laminin and/or fibronectin, these are preferred as coatings for synthetic nerve grafts seeded with SCs

Outcome of non-instrumented lumbar spinal surgery in obese patients: a systematic review

Introduction: Lumbar spinal decompression procedures are well known in their techniques and outcomes. However, outcomes of lumbar spinal surgery in patients with obesity are relatively unknown. The aim of this review is to assess the effect of obesity on post-operative outcomes of lumbar non-instrumented decompressive spinal surgery. Methods and materials: A literature search through PubMed, Embase, Web of Science and Cochrane was performed. Articles were included if they reported outcomes of obese patients after non-instrumented lumbar decompression surgery, if these outcomes were described using patient-reported outcome measures and if there was at least two months of follow-up. Risk of bias was assessed using an adjusted version of the Cowley score. Results: From the 222 unique articles, 14 articles, comprising 13,653 patients, met the inclusion criteria. Eight out of 14 studies had a low risk of bias, while the remaining six had an intermediate risk of bias. Thirteen studies evaluated leg and back pain, and the vast majority demonstrated less decrease in pain in the obese group. Six studies evaluated disability and all but one showed less improvement in obese patients. Five studies evaluated functionality and wellbeing and all but one showed less satisfactory outcome in obese patients. Conclusions: Literature does not reveal a difference in clinical outcome nor in complications in patients undergoing non-instrumented lumbar surgery with a BMI lower than 30 or equal to or higher than 30. This may be used by physicians to inform patients prior to lumbar decompression surgery

Clinical outcome in decompression alone versus decompression and instrumented fusion in patients with isthmic spondylolisthesis:A prospective cohort study

OBJECTIVE In the surgical treatment of isthmic spondylolisthesis, it is debatable whether instrumented fusion is mandatory in addition to decompression. The objective of this prospective cohort study was to assess the long-term effect of decompression alone compared with decompression and instrumented fusion in patients who underwent the intervention of their own preference. The results were compared with those in patients who underwent randomly assigned treatment. METHODS The authors performed a prospective observational multicenter cohort study, including 91 patients with isthmic spondylolisthesis assigned to undergo either decompression alone (n = 44) or decompression and fusion (n = 47). The main outcomes were the Roland-Morris Disability Questionnaire (RDQ) scores and the patient's perceived recovery at the 2-year follow-up. Secondary outcomes were visual analog scale (VAS) leg pain and back pain scores and the reoperation rate. A meta-analysis was performed for data from this cohort study (n = 91) and from a randomized controlled trial (RCT) previously reported by the authors (n = 84). Subgroup analyses were performed on these combined data for age, sex, weight, smoking, and Meyerding grade. RESULTS At the 12-week follow-up, improvements of RDQ scores were comparable for the two procedures (decompression alone [D group] 4.4, 95% CI 2.3-6.5; decompression and fusion [DF group] 5.8, 95% CI −4.3 to 1.4; p = 0.31). Likewise, VAS leg pain scores (D group 35.0, 95% CI 24.5-45.6; DF group 47.5, 95% CI 37.4-57.5; p = 0.09) and VAS back pain scores (D group 23.5, 95% CI 13.3-33.7; DF group 34.0, 95% CI 24.1-43.8; p = 0.15) were comparable. At the 2-year follow-up, there were no significant differences between the two groups in terms of scores for RDQ (difference −3.1, 95% CI −6.4 to 0.3, p = 0.07), VAS leg pain (difference −7.4, 95% CI −22.1 to 7.2, p = 0.31), and VAS back pain (difference −11.4, 95% CI −25.7 to 2.9, p = 0.12). In contrast, patient-perceived recovery from leg pain was significantly higher in the DF group (79% vs 51%, p = 0.02). Subgroup analyses did not demonstrate a superior outcome for decompression alone compared with decompression and fusion. Nine patients (20.5%) underwent reoperation in total, all in the D group. The meta-analysis including both the cohort and RCT populations yielded an estimated pooled mean difference in RDQ of −3.7 (95% CI −5.94 to −1.55, p = 0.0008) in favor of decompression and fusion at the 2-year follow-up. CONCLUSIONS In patients with isthmic spondylolisthesis, at the 2-year follow-up, patients who underwent decompression and fusion showed superior functional outcome and perceived recovery compared with those who underwent decompression alone. No subgroups benefited from decompression alone. Therefore, decompression and fusion is recommended over decompression alone as a primary surgical treatment option in isthmic spondylolisthesis.</p

Design of the Verbiest trial: cost-effectiveness of surgery versus prolonged conservative treatment in patients with lumbar stenosis

Background: Degenerative changes of lumbar spine anatomy resulting in the encroachment of neural structures are often regarded progressive, ultimately necessitating decompressive surgery. However the natural course is not necessarily progressive and the efficacy of a variety of nonsurgical interventions has also been described. At present there is insufficient data to compare surgical and nonsurgical interventions in terms of their relative benefit and safety. Previous attempts failed to provide clear clinical recommendations or to distinguish subgroups that substantially benefit from a certain treatment strategy. We present the design of a randomized controlled trial on (cost-) effectiveness of surgical decompression versus prolonged conservative treatment in patients with neurogenic intermittent claudication caused by lumbar stenosis. Methods/Design. The aim of the Verbiest trial is to evaluate the effectiveness of prolonged conservative treatment compared to decompressive surgery. The study is a multi-center randomized controlled trial with two parallel groups design. Patients (age over 50) presenting

Association between clinical findings and the presence of lumbar spine osteoarthritis imaging features:A systematic review

OBJECTIVE: Spinal osteoarthritis is difficult to study and diagnose, partly due to the lack of agreed diagnostic criteria. This systematic review aims to give an overview of the associations between clinical and imaging findings suggestive of spinal osteoarthritis in patients with low back pain to make a step towards agreed diagnostic criteria.DESIGN: We searched MEDLINE, Embase, Web of Science, and CINAHL from inception to April 29, 2021 to identify observational studies in adults that assessed the association between selected clinical and imaging findings suggestive of spinal osteoarthritis. Risk of bias was assessed using the Newcastle Ottawa Scale and the quality of evidence was graded using an adaptation of the GRADE approach.RESULTS: After screening 7902 studies, 30 met the inclusion criteria. High-quality evidence was found for the longitudinal association between low back pain (LBP) intensity, and both disc space narrowing and osteophytes, as well as for the association between LBP-related physical functioning and lumbar disc degeneration, the presence of spinal morning stiffness and disc space narrowing and for the lack of association between physical functioning and Schmorl's nodes.CONCLUSIONS: There is high- and moderate-quality evidence of associations between clinical and imaging findings suggestive of spinal osteoarthritis. However, the majority of the studied outcomes had low or very low-quality of evidence. Furthermore, clinical and methodological heterogeneity was a serious limitation, adding to the need and importance of agreed criteria for spinal osteoarthritis, which should be the scope of future research.</p

Influence of low back pain and prognostic value of MRI in sciatica patients in relation to back pain

Background: Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica patients with and without disabling back pain. Methods: The study population contained patients with sciatica who underwent a baseline MRI to assess eligibility for a randomized trial designed to compare the efficacy of early surgery with prolonged conservative care for sciatica. Two neuroradiologists and one neurosurgeon independently evaluated all MR images. The MRI readers were blinded to symptom status. The MRI findings were compared between sciatica patients with and without disabling back pain. The presence of disabling back pain at baseline was correlated with perceived recovery at one year. Results: Of 379 included sciatica patients, 158 (42%) had disabling back pain. Of the patients with both sciatica and disabling back pain 68% did reveal a herniated disc with nerve root compression on MRI, compared to 88% of patients with predominantly sciatica (P,0.001). The existence of disabling back pain in sciatica at baseline was negatively associated with perceived recovery at one year (Odds ratio [OR] 0.32, 95% Confidence Interval 0.18-0.56, P,0.001). Sciatica patients with disabling back pain in absence of nerve root compression on MRI at baseline reported less perceived recovery at one year compared to those with predominantly sciatica and nerve root compression on MRI (50% vs 91%, P,0.001). Conclusion: Sciatica patients with disabling low back pain reported an unfavorable outcome at one-year follow-up compared to those with predominantly sciatica. If additionally a clear herniated disc with nerve root compression on MRI was absent, the results were even worse. Copyright

Full endoscopic versus open discectomy for sciatica:randomised controlled non-inferiority trial

OBJECTIVE: To assess whether percutaneous transforaminal endoscopic discectomy (PTED) is non-inferior to conventional open microdiscectomy in reduction of leg pain caused by lumbar disc herniation. DESIGN: Multicentre randomised controlled trial with non-inferiority design. SETTING: Four hospitals in the Netherlands. PARTICIPANTS: 613 patients aged 18-70 years with at least six weeks of radiating leg pain caused by lumbar disc herniation. The trial included a predetermined set of 125 patients receiving PTED who were the learning curve cases performed by surgeons who did not do PTED before the trial. INTERVENTIONS: PTED (n=179) compared with open microdiscectomy (n=309). MAIN OUTCOME MEASURES: The primary outcome was self-reported leg pain measured by a 0-100 visual analogue scale at 12 months, assuming a non-inferiority margin of 5.0. Secondary outcomes included complications, reoperations, self-reported functional status as measured with the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery. Outcomes were measured until one year after surgery and were longitudinally analysed according to the intention-to-treat principle. Patients belonging to the PTED learning curve were omitted from the primary analyses. RESULTS: At 12 months, patients who were randomised to PTED had a statistically significantly lower visual analogue scale score for leg pain (median 7.0, interquartile range 1.0-30.0) compared with patients randomised to open microdiscectomy (16.0, 2.0-53.5) (between group difference of 7.1, 95% confidence interval 2.8 to 11.3). Blood loss was less, length of hospital admission was shorter, and timing of postoperative mobilisation was earlier in the PTED group than in the open microdiscectomy group. Secondary patient reported outcomes such as the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery, were similarly in favour of PTED. Within one year, nine (5%) in the PTED group compared with 14 (6%) in the open microdiscectomy group had repeated surgery. Per protocol analysis and sensitivity analyses including the patients of the learning curve resulted in similar outcomes to the primary analysis. CONCLUSIONS: PTED was non-inferior to open microdiscectomy in reduction of leg pain. PTED resulted in more favourable results for self-reported leg pain, back pain, functional status, quality of life, and recovery. These differences, however, were small and may not reach clinical relevance. PTED can be considered as an effective alternative to open microdiscectomy in treating sciatica. TRIAL REGISTRATION: NCT02602093ClinicalTrials.gov NCT02602093

Lumbale herniaoperatie: Endoscopisch of open?

_Achtergrond en het waarom van de studie_ In Nederland vinden jaarlijks veel operaties voor een lumbale discushernia plaats. Patiënten krijgen meestal een open microdiscectomie, waarbij de hernia wordt opgeheven via een klein sneetje in de rug en de zenuwwortel wordt vrijgelegd (figuur a). Een andere techniek is percutane transforaminale endoscopische discectomie (PTED) (figuur b). Hierbij wordt de hernia onder indirect zicht opgeheven door een kleinere snee van 8 mm via het wortelkanaal, dus meer vanaf de zijkant. PTED vindt plaats in dagbehandeling onder lichte sedatie, waardoor de patiënt gedurende de ingreep aanspreekbaar is. Mogelijke voordelen van deze techniek zijn minder risico op littekenvorming en een snellere revalidatie. Een mogelijk nadeel is een groter risico op recidieven omdat er minder discusmateriaal kan worden uitgeruimd. PTED behoort nog niet tot het basispakket, omdat Zorginstituut Nederland meent dat PTED niet voldoet aan de stand van de wetenschap en praktijk. Met de PTED-studie willen wij de hypothese toetsen dat PTED bij patiënten met een lumbale hernia niet minder effectief is dan open microdiscectomie. Daarnaast zullen wij ook de kosteneffectiviteit analyseren. _Vraagstelling:_ Is PTED niet minder effectief en niet minder kosteneffectief dan microdiscectomie bij patiënten met lumbosacraal radiculair syndroom door een discushernia