Are high lumbar punctures safe? A magnetic resonance imaging morphometric study of the conus medullaris

A high lumbar puncture (LP) at L2-L3 or above is often necessary to consider on technical grounds, but complications of conus medullaris (CM) damage during high LP are potentially concerning. We hypothesized that a high LP might be safer than previously thought by accounting for movements of the CM upon patient positional changes. We retrospectively reviewed standard normal supine lumbar spine magnetic resonance imaging of 58 patients and used electronic calipers on axial images at the T12-L1, L1-L2, and L2-L3 disc levels to measure the transverse diameter of the CM relative to the size of the dorsal thecal sac space (DTSS) through which a spinal needle could be inserted. On 142 axial images, the means for CM diameters were 8.2, 6.0, and 2.9 mm at the three levels, respectively. We then used known literature mean CM displacement values in the legs flexed and unflexed lateral decubitus position (LDP) to factor in CM shifts to the dependent side. We found that at all three levels, the likely positional shift of the CM would be too small and insufficient to displace the entire CM out of the DTSS. However, if needle placement could be confined to the midsagittal plane, an LP in the unflexed LDP would theoretically be entirely safe at both L1-L2 and L2-L3, and almost so at L2-L3 in the legs flexed LDP. Thus, high LPs at L1-L2 and L2-L3 are in theory likely safer than considered previously, more so in the legs unflexed than in the flexed LDP. Clin. Anat. 32:618-629, 2019. © 2019 Wiley Periodicals, Inc.

Obstetrical Outcomes in Adult Patients Born with Complex Anorectal Malformations and Cloacal Anomalies: A Literature Review

Patients born with complex anorectal malformations often have associated Müllerian anomalies, which might affect fertility and obstetrical outcomes. Other vertebral-anorectal-tracheoesophageal-renal-limb associations, such as renal or cardiac anomalies, could also affect pregnancy intention, fertility rates, and recommendations about mode of delivery or obstetrical outcomes. Associated conditions present at birth, like hydrocolpos, could also potentially affect fertility. Depending on the complexity of the anomaly, primary reconstruction might include vaginoplasty, vaginal interposition, perineal body reconstruction, and extensive pelvic dissection. After the initial reconstruction, patients might have multiple additional surgeries for stoma reversal, bladder augmentation, and creation of conduits, all with potential for pelvic adhesions. Pregnancy intention, fertility rates, mode of delivery, and obstetrical outcomes data are limited in this patient population, making it challenging to counsel patients and their families. We sought to evaluate all available literature in an attempt to better counsel families. A PubMed literature search was undertaken to review this topic. Search terms of "cloaca," "anorectal malformation," "pregnancy," "cloacal exstrophy," "vaginal delivery," and "cesarean section" were used and citation lists from all identified articles were checked to ensure that all possible articles were included in the review. We also outline comorbidities from the fetal period to adulthood that might affect reproductive health. Of the articles on anorectal and cloacal anomalies, 13 reports were identified that covered obstetrical outcomes. They were in patients with previous anorectal malformation, cloaca, and cloacal exstrophy repair. Twenty-four pregnancies were reported in 16 patients. Two ectopic pregnancies, 5 spontaneous miscarriages, 1 triplet pregnancy, and 16 singleton pregnancies were reported with a total of 19 live births. Regarding the method of conception, 15/18 pregnancies occurred spontaneously and 3/18 were via assisted reproductive technology with in vitro fertilization. There were 19 live births, of which at least 8 were preterm. Müllerian anatomy was reported in 8 of 13 articles. Only 2 patients underwent vaginal delivery (1 patient with repaired cloaca malformation had an operative vaginal delivery and 1 patient with repaired imperforate anus with rectovaginal fistula had a normal spontaneous vaginal delivery). The remaining patients all underwent a cesarean section. There were no reported cases of maternal mortality, and maternal morbidity was limited to recurrent urinary tract infections and worsening chronic kidney disease. There is a paucity of information regarding obstetrical outcomes in adult anorectal and cloaca patients. However, patients with previous cloacal repairs have achieved pregnancy spontaneously, as well as with in vitro fertilization. Patients with repaired cloacal malformations are at increased risk of preterm birth and cesarean delivery. Most patients with cloacal anomalies have an associated Müllerian anomaly and therefore have an increased risk of preterm labor. From our review we conclude that contraception should be offered to patients not desiring pregnancy, and cesarean section is likely the preferred mode of delivery. On the basis of this review, we recommend proactive data collection of all such patients to document outcomes and collaboration among providers and between centers devoted to this complex patient population.

Complications after spinal anesthesia in adult tethered cord syndrome

Since little has been reported about complications of spinal anesthesia in adult tethered cord syndrome (TCS), we sought to delineate the characteristics of the condition.A total of 4 cases of adult TCS after spinal anesthesia were reviewed. The medical charts of the patients were obtained. Anesthesia, which was combined spinal and epidural anesthesia or spinal anesthesia was performed, and follow-up were carried out in all patients.The most common neurological symptom of adult TCS before surgery was occasional severe pain in back, perineal region, or legs. Frequent micturition, diminished knee and ankle reflexes, and difficulty in bending were exhibited in partial patients. Paraesthesia of perineal region or/and lower extremities existed 2 to 3 days after spinal anesthesia in all the cases. Weakness of lower extremities existed in 1 case. Lumbar magnetic resonance imaging showed the low location of conus medullaris. At follow-up, 3 cases recovered completely within 3 weeks, and 1 case underwent permanent disability.These cases suggest anesthesiologists and surgeons alert to the association of adult TCS and spinal anesthesia. Spinal anesthesia should be prohibited in patients with adult TCS to prevent neurological damages.

Abdominal circumference but not the degree of lumbar flexion affects the accuracy of lumbar interspace identification by Tuffier's line palpation method: an observational study

Background

Lumbar puncture for spinal or epidural anesthesia is commonly performed by palpating bony landmarks, but identification of the desired intervertebral level is often inaccurate. It is unclear whether such inaccuracy is related to patient factors, such as body mass index and degree of lumbar flexion. We hypothesized that overweight patients and patients with less of an ability to hyperflex their lumbar spines are prone to inaccurate lumbar spinous intervertebral level identification.

Methods

52 adult volunteers were included in this study. 7 anesthesiologists with different years of experience identified and marked subjects’ levels of the iliac crests, then marked the presumed interspaces. Lumbar X-ray was then performed with metal markers, and actual radiographic findings were identified and compared to the initial markings.

Results

Patients with larger abdominal circumferences (mean (SD), 94.0(12.1) cm), higher body mass indices (25.9(3.9) kg/m²), and aged between 50 and 70 years old had lumbar interspaces that were higher than the presumed level; patients with smaller abdominal circumferences (82.8(13.5) cm) and lower body mass indices (21.6(4.1) kg/m²) had intervertebral levels that were lower than the presumed level. Cobb’s angle, indicating the degree of lumbar flexion, did not affect the accuracy obtained.

Conclusions

Patients’ abdominal circumference, body mass index, and age are factors that may impact the accuracy of lumbar level identification. Tuffier’s line, as identified by palpation, does not seem to be a reliable landmark for proper lumbar interspace identification in all cases.

The termination level of the conus medullaris and lumbosacral transitional vertebrae

BACKGROUND

The presence of lumbosacral transitional vertebrae (LSTV) may affect the variation of the termination level of conus medullaris (TLCM). However, there have been few studies examining the association between the distribution of the TLCM and LSTV, especially in young patients. The purpose of this investigation was therefore to assess the relationship between the TLCM and LSTV in young patients.

METHODS

A total of 379 patients with lumbar herniated disks were included in this study. There were 249 males and 130 females, with a mean age of 31 years (range 15-44). The patients were classified into three groups: (1) L4/TV group (7 %): 28 patients with sacralization of the fifth lumbar vertebrae; (2) L5/TV group (11 %): 41 patients with lumbarization of the sacrum; and, (3) normal group (82 %): 310 patients without LSTV. TLCM was assessed using MRI.

RESULTS

The median TLCM of the normal, L4/TV and L5/TV groups was the middle third of L1, the upper third of L1 and the lower third of L1, respectively. The TLCM in the L4/TV group was significantly higher than that observed in the normal group (p < 0.001), while that in the L5/TV group was significantly lower than observed in the normal group (p < 0.001).

CONCLUSIONS

The presence of LSTV affected the variation of the TLCM. Therefore, the distribution of the TLCM with or without lumbosacral TV may help clinicians to identify the neurological discrepancies observed among neurologic injuries at the thoracolumbar junction.