Outcome of ultrasonographic imaging in infants with sacral dimple

Utility of routine mid-trimester fetal ultrasound scan in detecting filar cysts and follow-up outcomes

PURPOSE

To assess the value of routine mid-trimester fetal ultrasound scans in detecting FCs, as well as the related ultrasound and clinical follow-up outcomes.

METHODS

A retrospective analysis was conducted on 1064 fetuses who underwent standardized ultrasound screening during the mid-trimester. During the examination, high-frequency ultrasound was used to examine the fetal spine. Different frequency ultrasound probes were used to compare and analyze the detection rates of FCs. We conducted follow-up ultrasound observations on all FCs and conducted long-term follow-up observations in terms of the motor function of the children after birth.

RESULTS

Among 1064 fetuses detected by ultrasound, a total of 910 fetuses were completely evaluated using high-frequency and low-frequency ultrasound, and 24 FCs were found. In all 24 cases of FCs, 7 cases were detected using low-frequency ultrasound, while high-frequency ultrasound detected all cases. There was a significant difference in the detection rates between the two groups (χ2 = 26.323, P = 0.000). Of all the 24 FCs, 21 cysts disappeared spontaneously (87.5%); one fetus was induced for abortion due to a concurrent cleft lip; after multiple ultrasound examinations, it was found that the cyst persisted in one fetus; one case was not followed up by ultrasound. There was no statistically significant difference in the start of sitting and crawling time between the control group and the FCs group.

CONCLUSION

Routine mid-trimester fetal ultrasound scan detect FCs, particularly when high-frequency ultrasound probes were routinely applied. Most FCs detected by prenatal ultrasound spontaneously disappear and have no impact on the motor function of the fetus after birth (with the conus medullaris located at or above the L3 level). The shortest time interval from the detection to the disappearance of the cyst was 11 days.

Prenatal ultrasound diagnosis and prognosis of fetus with isolated filar cyst: a retrospective analysis

Objective

This study aimed to investigate the prenatal ultrasonographic diagnosis and prognosis of fetuses with isolated filar cysts (FCs).

Methods

The ultrasonographic features, reasons for missed diagnosis, and prognosis of eight isolated FCs diagnosed using ultrasound were analyzed retrospectively through follow-up.

Results

Eight isolated FCs showed round or fusiform cystic anechoic areas at the end of the conus medullaris. Among them, six cases were prenatally diagnosed and the other two cases were diagnosed after birth. Of the six cases diagnosed prenatally, four (66.7%) disappeared during pregnancy, and the shortest time to disappearance was 1 month after the first diagnosis. All patients were followed up without any clinical symptoms or functional abnormalities.

Conclusion

Isolated FCs may exhibit physiological variations that disappear spontaneously during pregnancy and usually have no clinical symptoms. They are usually benign and have a good prognosis. Ultrasonography is helpful for the diagnosis and follow-up of FCs.

Spontaneous Disappearance of Filar Cysts Diagnosed by Transabdominal Ultrasonography: A Report of Three Cases

Filar cysts (FCs) can be detected using ultrasound before or after delivery. They usually present as anechoic structures with a clear boundary just caudal to the lower end of the conus medullaris. They are generally considered a physiological variation and do not affect health. Some studies have pointed out that FCs in children can disappear spontaneously, as identified by ultrasound or magnetic resonance imaging. Three cases of FCs diagnosed by prenatal transabdominal ultrasound were reported in this study, and it was observed that FCs could disappear spontaneously in utero. The shortest time of disappearance was 4 weeks.

Incidence of Occult Spinal Dysraphism Among Infants With Cutaneous Stigmata and Proportion Managed With Neurosurgery: A Systematic Review and Meta-analysis

IMPORTANCE

Occult spinal dysraphism (OSD) is the most common congenital spinal anomaly. Cutaneous anomalies such as skin dimples or deviated gluteal folds are well known as stigmata of OSD and are indicators for further evaluation; however, the association between cutaneous anomalies and OSD has not been systemically evaluated.

OBJECTIVE

To evaluate the incidence of OSD and the proportion of OSD cases managed with a neurosurgical intervention among neonates or infants with various cutaneous stigmata.

DATA SOURCES

PubMed and Embase databases were searched for studies published up to July 25, 2018, that evaluated the proportion of OSD cases in neonates or infants with cutaneous stigmata. Search terms included ultrasound, dysraphism, dimple, and infant or neonate. The search was limited to English-language publications.

STUDY SELECTION

Two reviewers selected the studies evaluating the incidence of OSD among neonates or infants with cutaneous stigmata.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for data extraction were followed. Pooled proportions of OSD cases and OSD cases that were managed with a neurosurgical intervention were obtained using the generalized linear mixed model and maximum likelihood method.

MAIN OUTCOME AND MEASURES

The pooled incidence of OSD and OSD cases managed with neurological surgery among patients with cutaneous stigmata was the primary outcome. This outcome was also evaluated in each subgroup, and heterogeneity was explored using subgroup analysis.

RESULTS

A total of 15 studies, involving 6558 neonate or infant patients with various cutaneous stigmata, were included. The pooled proportion of OSD cases among the patients with cutaneous stigmata was 2.8% (95% CI, 2.1%-3.8%; I2 = 51.6%), and the proportion managed with neurological surgery was 0.6% (95% CI, 0.3%-1.3%; I2 = 66.4%). Cases with combined stigmata showed a significantly higher association with OSD than those with a single stigma (10.5% [95% CI, 6.9%-15.8%] vs 2.3% [%, 95% CI, 1.5%-3.5%]; P < .001). The pooled proportion of OSD cases among patients with an atypical dimple was significantly higher than among those with simple dimple (8.8% [95% CI, 4.5%-16.6%] vs 0.6% [95% CI of 1.4%-2.1%]; P = .001).

CONCLUSIONS AND RELEVANCE

The proportion of OSD in healthy, asymptomatic patients with midline cutaneous stigmata was low, and the proportion of patients who underwent a neurosurgical intervention was even lower. However, a careful evaluation as well as potential spinal magnetic resonance imaging is recommended for neonates or infants with combined stigmata or an atypical dimple for possible high-risk lesions.

Filar cysts in rare cases may progress in size, particularly when associated with filar lipoma

PURPOSE

Filar cysts (FCs) are detected incidentally on ultrasonography (US) of the neonatal spine. Their clinical significance has not been widely discussed in the literature because FCs are usually asymptomatic. This study aimed to investigate the clinical features of FCs and distinguish FCs that warrant attention.

METHODS

We retrospectively analyzed 396 patients with lumbosacral skin stigmata. Patients who were younger than 1 month old at reference underwent US initially, and those older than 1 month of age underwent magnetic resonance imaging (MRI) at the age of 5-12 months. Patients with an FC in the US underwent subsequent MRI at the age of 5-12 months. Patients with an FC were followed clinically for at least 3 years.

RESULTS

FCs were identified in 56 (14.1%) patients. Of the 195 children who underwent US initially, FCs were detected in 49 (25.1%) children. FCs were detected in seven children who underwent MRI initially. Of the 50 children with FCs who underwent MRI at the age of 5-12 months, FCs in 20 patients (40%) showed natural regression and FCs in 30 patients (60%) remained. Two of these 30 patients showed progression in size of the FC, and in both cases, the FCs were associated with a filar lipoma; however, the resected cysts were not neoplastic and did not have obvious clinical significance.

CONCLUSIONS

Our study characterizes clinical features of filar cysts. Two-thirds of FCs remained in late infancy. The best sequence of MRI to follow-up FCs is heavily T2-weighted images.

Dorsal midline cutaneous stigmata associated with occult spinal dysraphism in pediatric patients

PURPOSE

To investigate the prevalence of occult spinal dysraphism (OSD) and subsequent neurosurgery in pediatric patients with isolated or combined dorsal midline cutaneous stigmata with or without other congenital malformations.

METHODS

We carried out a retrospective review of patients who underwent sonography or magnetic resonance imaging (MRI) for OSD because of suspicion of dorsal midline cutaneous stigmata (presumed to be a marker for OSD) between January 2012 and June 2017. Information about patient characteristics, physical examination findings, spinal ultrasound and MRI results, neurosurgical notes, and accompanying congenital anomalies was collected.

RESULTS

Totally 250 patients (249 ultrasound and one MRI screening) were enrolled for analysis. Eleven patients underwent secondary MRI examinations. The prevalence of OSD confirmed by an MRI was 2.4% (6 patients including one MRI screening). Five patients (2%) had tethered cord and underwent prophylactic neurosurgery, 3 of whom had a sacrococcygeal dimple and a fibrofatty mass. Prevalence of tethered cord increased as markers associated with a sacrococcygeal dimple increased (0.5% of the isolated marker group, 8.1% of the 2-marker group, and 50% of the 3-marker group). Incidence of OSD with surgical detethering in 17 other congenital anomaly patients was 11.8%, which was higher than the 1.3% in 233 patients without other congenital anomalies.

CONCLUSION

Our results suggest that the presence of dorsal midline cutaneous stigmata, particularly fibrofatty masses, along with a sacrococcygeal dimple is associated with OSD or cord tethering requiring surgery. OSD should be suspected in patients with concurrent occurrence of other congenital anomalies.