The management of conus lipomas in children can be conservative, but prophylactic radical removal has been proven to be the only way to ameliorate the natural history of this disease. We started our surgical practice aiming toward total removal of spinal cord lipomas in 2017. This study aims to present our early results. Patients younger than 12 years of age that had a conus lipoma surgically treated between April 2017 and April 2024 were included in the study. We analysed the preoperative presence of symptoms, defined the subtype of lipoma, the presence of syringomyelia and the degree of rotation of the placode. Among the operative data, we reviewed the preservation of the bulbocavernosus reflex (BCR). Postoperatively, we analysed the onset of new neurological or urological deficits and calculated the cord/sac ratio and the amount of residual fat. A total of 19 patients have been included, with a median follow-up of 55.1 months. Dorsal lipomas were 21%, transitional 73.6% and chaotic 5.2% cases, while using the new classification of spinal lipomas (NCSL) type 1 were 63.1%, type 2 were 31.5%, and type 3 were 5.2%. Transitional and chaotic lipomas were significantly associated with a lower level of the conus (p = 0.0002), as type 2 and 3 of the NCSL (p = 0.0441). The patients were symptomatic in 31.5% and asymptomatic in 68.4% of cases. The preoperative presence of symptoms was associated with an age at surgery higher than 3 years (p = 0.0006). The median age at surgery was 65 months. The residual fat tissue was < 20 mm3 in 36.8%, 20-1000 mm3 in 47.3% and > 1000 m3 in 15.7%. A higher residual fat was associated with transitional and chaotic lipomas (p = 0.0082) and with types 2 and 3 (NCSL) (p = 0.0409). The median cord/sac ratio was 38.1%. After surgery, a permanent urinary deterioration occurred in 5.2% and a sensory deficit in 21%. The onset of permanent urological deficits was significantly associated with the loss of the BCR (p = 0.0012). Our results confirm the difficulty of achieving a safe and radical excision in transitional and chaotic (NCSL types 2 and 3) lipomas. These lipomas were significantly related to a higher postoperative amount of residual fat and to the occurrence of complications. For these lesions, the concept of radical resection should be shifted towards a concept of untethering by means of partial resection with maximal preservation of neurological function.

Total/near-total resection (TR/NTR) of complex lumbosacral lipomas (CSL) is reported to be associated with better long-term functional outcomes and lower symptomatic re-tethering rates. We report our institutional experience for CSL resection in affected children. This is a single-institution, retrospective study. Inclusion criteria consist of patients with CSL with dorsal, transitional and chaotic lipomas based on Pang et al's classification. The study population is divided into 2 groups: asymptomatic patients with a normal preoperative workup referred to as 'prophylactic intent' and 'therapeutic intent' for those with pre-existing neuro-urological symptoms. Primary aims are to review factors that affect post-operative clean intermittent catheterization (CIC), functional outcomes based on Necker functional score (NFS), and re-tethering rates. 122 patients were included from 2000 to 2021. There were 32 dorsal lipomas (26.2 %), 74 transitional lipomas (60.7 %), and 16 chaotic lipomas (13.1 %). 82 % patients achieved TR/NTR. Favourable NFS at 1-year was 48.2 %. The re-tethering rate was 6.6 %. After multivariable analysis, post-operative CIC was associated with median age at surgery (p = 0.026), lipoma type (p = 0.029), conus height (p = 0.048) and prophylactic intent (p < 0.001). Next, extent of lipoma resection (p = 0.012) and the post-operative CSF leak (p = 0.004) were associated with re-tethering. Favourable NFS was associated with lipoma type (p = 0.047) and prophylactic intent surgery (p < 0.001). Our experience shows that TR/NTR for CSL is a feasible option to prevent functional deterioration and re-tethering. Efforts are needed to work on factors associated with post-operative CIC.

Conus region lumbosacral lipomas (LSLs) are highly heterogeneous in their morphology, clinical presentation, and outcome, with an incompletely understood natural history and often treacherous surgical anatomy. This systematic review aims to critically evaluate and assess the strength of the current LSL evidence base to guide management strategies. According to a systematic review following PRISMA guidelines, a search was conducted using the key term "lumbosacral lipoma" across MEDLINE (OVID), Embase, Cochrane Library, and PubMed databases from January 1951 to April 2021. All studies containing ten or more paediatric conus lipomas were included. Data heterogeneity and bias were assessed. A total of 13 studies were included, containing 913 LSLs (predominantly transitional type-58.5%). Two-thirds (67.5%) of all patients (treated and non-treated) remained clinically stable and 17.6% deteriorated. Neuropathic bladder was present in 8.6% at final follow-up. Of patients managed surgically, near-total resection vs. subtotal resection deterioration-free survival rates were 77.2-98.4% and 10-67% respectively. 4.5% (0.0-27.3%) required re-do untethering surgery. Outcomes varied according to lipoma type. Most publications contained heterogeneous populations and used variable terminology. There was a lack of consistency in reported outcomes. Amongst published series, there is wide variability in patient factors such as lipoma type, patient age, and methods of (particularly urological) assessment. Currently, there is insufficient evidence base upon which to make clear recommendations for the management of children with LSL. There is an imperative for neurosurgeons, neuroradiologists, and urologists to collaborate to better standardise the terminology, assessment tools, and surgical interventions for this challenging group of conditions.

This review summarises the classification, anatomy and embryogenesis of complex spinal cord lipomas and describes in some detail the technique of total lipoma resection and radical reconstruction of the affected neural placode. Its specific mission is to tackle two main issues surrounding the management of complex dysraphic lipomas: whether total resection confers better long-term benefits than partial resection and whether total resection does better than conservative treatment, i.e. no surgery, for asymptomatic lipomas. Accordingly, the 24-year progression-free survival data of the senior author and colleagues' series of over 300 cases of total resection are compared with historical data from multiple series (including our own) of partial resection, and total resection data specifically for asymptomatic lesions are compared with the two known series of non-surgical treatment of equivalent patients. These comparisons so far amply support the author's recommendation of total resection for most complex lipomas, with or without symptoms. The notable exception is the asymptomatic chaotic lipoma, whose peculiar anatomical relationship with the neural tissue defies even our aggressive surgical approach, and consequently projects worse results (admittedly of small number of cases) than for the other two lipoma subtypes of dorsal and transitional lesions. Prophylactic resection of asymptomatic chaotic lipomas is therefore not currently endorsed. We have also recently found that some dorsal lipomas with clear outline of the conus on preoperative imaging had a significantly better long-term prognosis of preserving neurourological functions without surgery. Whether this subset of lipomas should be managed conservatively until symptoms arise is now an open question awaiting a longer follow-up of a larger cohort of such patients.

The objective of this study was to assess the prevalence and spectrum of spinal dysraphism in a cohort of children with cloacal exstrophy (CEX) using MRI. Children with CEX presenting between 1999 and 2019 with baseline spinal MRI were included. The images were reviewed in consensus to assess the type of dysraphism. The dysraphisms were initially reviewed and described based on their descriptive anatomy, and then classified according to anomalies of gastrulation, primary neurulation, or secondary neurulation. Thirty-four children were included. Thirty-three of these children had closed spinal dysraphism, and 1 had a normal spine. Of the 33 cases of closed spinal dysraphism, the conus and/or filum terminale were involved in all cases. The most common malformations were spinal lipoma (n = 20) and terminal myelocystocele (n = 11). The lipomas were heterogeneous: 4 dorsal, 9 transitional, 4 chaotic, and 3 terminal. A large subgroup (10/20, 50%) within the lipomas had an unusual morphology of noncontiguous double lipomas, the proximal fat related to the conus and the distal fat within the filum. These were difficult to characterize using existing classifications. In 2 cases, only a thickened filum was noted. The majority of these malformations were compatible with a disorder of secondary neurulation. Complex spinal dysraphisms are consistently associated with CEX. The unusual dysraphism patterns found in this group of patients highlight the limitations of current embryological classifications. Given the propensity for neurological deterioration in this group of patients, spinal MRI should be routinely performed. The type and distribution of malformations seen have implications for the wider understanding of the pathogenesis and classification of lumbosacral lipomas.