The lumbar autonomic nerves in males: a few anatomical insights into anterior lumbar interbody fusion

ALIF in a Spanish female cohort: No urinary and sexual complications or a gender bias?

BACKGROUND

The objective of the present study is to analyze urinary and sexual functions in females treated with ALIF and to describe possible complications not previously reported in the literature.

METHODS

We conducted a retrospective study of urinary and sexual functions in females treated with this technique in our hospital between 2019 and 2022. Inclusion criteria were: females treated with ALIF who provided informed consent.

RESULTS

22 patients consented to participate. The median age was 51.5 years, the median follow-up was 11.5 months, and there was an improvement in low back pain of 4 points on the postoperative (postop) visual analogue scale (VAS). Overall, 36.3% of patients reported postoperative urinary deterioration, including 27.3% with new-onset urinary incontinence. The international consultation on incontinence questionnaire-short form score worsened by 3.5 points. 77.2% maintained an active sexual life; within this group, there was a worsening of 2.4 points in the postop female sexual function index and 35.2% described worsening in sexual function. We hypothesized that age, underlying lumbar pathology and changes in postoperative VAS scores could be confounding factors; however, only the relationship between age and postoperative urinary deterioration reached statistical significance (p = 0.034).

CONCLUSIONS

The present study describes deterioration in urinary function in 36.3% and in sexual function in 35.2% after the procedure, findings also supported by specific scales. In view of the above, we cannot discount a possible gender bias in the literature. Despite that, we believe that ALIF is still an adequate technique, but studies of higher level of evidence should be conducted to improve the information process of our patients.

Implications of circadian disruption on intervertebral disc degeneration: The mediating role of sympathetic nervous system

The circadian clock orchestrates a broad spectrum of physiological processes, crucially modulating human biology across an approximate 24-hour cycle. The circadian disturbances precipitated by modern lifestyle contribute to the occurrence of low back pain (LBP), mainly ascribed to intervertebral disc degeneration (IVDD). The intervertebral disc (IVD) exhibits rhythmic physiological behaviors, with fluctuations in osmotic pressure and hydration levels that synchronized with the diurnal cycle of activity and rest. Over recent decades, advanced molecular biology techniques have shed light on the association between circadian molecules and IVD homeostasis. The complex interplay between circadian rhythm disruption and IVDD is becoming increasingly evident, with the sympathetic nervous system (SNS) emerging as a potential mediator. Synchronized with circadian rhythm through suprachiasmatic nucleus, the SNS regulates diverse physiological functions and metabolic processes, profoundly influences the structural and functional integrity of the IVD. This review synthesizes the current understanding of circadian regulation and sympathetic innervation of the IVD, highlighting advancements in the comprehension of their interactions. We elucidate the impact of circadian system on the physiological functions of IVD through the SNS, advocating for the adoption of chronotherapy as a brand-new and effective strategy to ameliorate IVDD and alleviate LBP.

Lumbar Sympathetic Trunk Injury: An Underestimated Complication of Oblique Lateral Interbody Fusion

OBJECTIVE

Lumbar sympathetic trunk (LST) injury is one of the major complications after oblique lumbar interbody fusion (OLIF). LST injury often manifests as unequal skin temperature in lower limbs after operation, and there may be a large number of missed diagnoses due to the lack of attention and different diagnostic methods. The study aimed to investigate the incidence and clinical characteristics of LST injury after OLIF.

METHODS

The data of patients with lumbar degenerative diseases who underwent OLIF in our hospital from April 2016 to October 2017 were retrospectively analyzed. Finally, a total of 54 patients were included. There were 10 males and 44 females, aged 58.4 ± 10.9 years. The skin temperature of lower limbs was measured before and a day after surgery. The patients were followed up at 1 week, 6 weeks, 6 months, and 2 years after the surgery. Likert five-point scale was used to evaluate the discomfort caused by LST injury. Injury severity score was introduced to grade injury degree according to the recovery time of postoperative symptoms. The chi-square test was used to analyze the association of incidence of lumbar sympathetic trunk (LST) injury with contributing factors, such as gender and number of surgical segments.

RESULTS

The unequal temperature was not found before surgery in all the patients. Postoperatively, 16 cases (29.6%) had difference of skin temperature more than 0.5 °C and were diagnosed with LST injury. Eight patients (14.8%) had self-perception of skin temperature differences, and 12 patients (22.2%) had other symptoms, such as muscle pain, numbness, and weakness, which were not statistically different between patients with and without lumbar sympathetic trunk injury (p > 0.05). In the 16 patients with LST injury, the difference of skin temperature between the two legs was 0.6 ± 0.1 °C on the first day, and the temperature difference lasted for 1.5-~12 months. According to Likert five-point scale, two cases (12.5%) were poor, and 14 cases (87.5%) were moderate immediately after surgery. Fifteen cases improved to some extent 6 weeks to 12 months after surgery.

CONCLUSION

Postoperative LST injury is mainly manifested by different temperature of lower limbs. The incidence was higher in patients with multi-segment OLIF than in those with single-segment OLIF, and the subjective experience of most patients with LST injury was moderate discomfort.

Iliolumbar vein: a challenge for the exposure of the L4-5 disc in the anterior approach to the lumbar spine

PURPOSE

Anterior lumbar spine arthrodesis has been increasingly prescribed. In order to obtain better exposure of the intervertebral discs, it is necessary to identify vascular structures depending on the level to be approached. Systematic ligation of the iliolumbar vein has been suggested for access to the L4-L5 level, which may be technically challenging. The goal of the present study was to determine a safe limit for separating the iliolumbar vein safely without the need for its ligation.

METHODS

In total, 2284 patients involving the topography of the iliolumbar vein were included. If this vein was up to 5 mm distant from the inferior border of the L4-L5 intervertebral disc, its ligature was performed. In cases that the distance was greater than 5 mm, only the retraction was performed without ligature.

RESULTS

A total of 115 ligatures were necessary (5% of cases). Among the 2169 cases with no ligature, bleeding due to ruptures occurred during traction in only 55 patients (3% of cases). The time taken for ligation ranged from five minutes to thirty-two minutes, with an average of 18.3 min per ligature. In cases in which ligatures were needed (distance less than 5 mm), there was loosening of the ligatures leading to bleeding in 23 cases (20% of ligatures).

CONCLUSIONS

Systematic ligature is not necessary for accessing the anterior route to the L4-L5 level, leading to a reduction in the time of surgery and avoiding serious vascular injuries that can occur.