The prone transpsoas technique was presented by Dr. Luiz Pimenta and William Taylor in 2020 and has attracted the attention of several spine surgeons owing to its advantages over traditional lateral lumbar interbody fusion, such as operative efficiency (single position) and lordosis correction/redistribution22–24.
The incidence of neurological complications following lateral lumbar interbody fusion (LLIF) varies across studies; however, it is a recognized risk factor associated with the procedure. neurological complications in 11.5% and 12.1% of patients, respectively, with anterior thigh pain and numbness being the most common complications. Most studies report that the majority of neurological deficits are temporary, while others caution against the possibility of long-lasting and debilitating effects, although these are rare and account for approximately 2% of the deficits. The present study reported a rate of 0.66% of persistent neurological deficits, which suggests that the difference between the data from the literature could originate from a mix of three factors: the first is the design of the study (a survey-based study), the second is the evolving definition of persistent deficit 25, and the third is the fact that the prone position yields a retraction of the psoas muscle concomitant with a retraction of the lumbar plexus, which enhances the safe working zone of the technique16,26.
Regarding the incidence of vascular complications following lateral lumbar interbody fusion (LLIF), most reports are case reports and small case series, although some authors have presented some concerns, mainly regarding upper levels and cases of anterior column release10,27. However, Kwon and Kim (2016) reported that serious complications such as vascular injury are rare. Similarly, Li et al. (2018) reported no vascular injuries in their study. According to a narrative review of the literature, Epstein 2020 reported that the incidence of major vascular injuries after LLIF was between 0% and 0.4%10. Furthermore, in a survey of surgeons with vast experience in lateral lumbar interbody fusion, comprising a total of 13,000 surgical cases, researchers reported a rate of 0.10% 9. Additionally, in another survey, members of the Italian Society of Lateral Access Surgery (SOLAS), comprising 1813 patients, reported a major vessel injury rate of 0.16% (3/1813)28. Finally, in a recent systematic review and meta-analysis, Farber et al. (2023) reported that, until recently, no cases of major vascular injuries were reported for prone transpsoas techniques29, which is similar to those reported in the present study, where the reported rate of major vascular injuries was 0.05%.
Finally, visceral complications following lateral lumbar interbody fusion (LLIF) are very rare, with most reported cases being derived from case reports. Hiji et al. (2017) reported that the proportion of visceral complications was very low, with values ranging from 0.93–1.38%11. According to a meta-analysis by Walker et al. (2019), the rate of visceral injuries varied from 0–1.3%30. Moreover, in a survey comprising 13,000 patients involving more than 40 surgeons, the prevalence of visceral injury was 0.08%9. This finding is similar to the results presented by the survey completed by the Italian SOLAS group, which demonstrated a 0.11% rate of visceral complications. These results are similar to those reported in the present study, which reported a 0.05% rate of visceral injury. Finally, in a study with fresh human cadavers, Pimenta et al. (2023) demonstrated that the risk of violating retroperitoneal structures in the prone position was significantly lower than that in the lateral position 31.
The present study had several limitations. First, the survey design is prone to be misled by the surgeon’s memory and ability to recall complications when completing the questionnaire. Second, the group of surgeons selected to answer the questionnaire were skilled and experienced, many with years of lateral surgery experience, which might not allow for a wider extrapolation of the findings.
Despite its limitations, the present survey demonstrated that the prone transpsoas technique, which involves a particular set of skilled surgeons, has a similar complication profile as the traditional lateral approach, with a tendency to reduce the rates of these complications, given the positional changes proportional to the PTP technique, compared to surveys with skilled surgeons performing traditional lateral lumbar interbody fusion.