TRANSILIAC ENDOSCOPIC ACCESS FOR TRANSFORAMINAL APPROACH AT L5-S1: CASES REPORT

ACESSO ENDOSCóPICO TRANSILíACO PARA ABORDAGEM TRANSFORAMINAL EM L5-S1: RELATO DE CASOS

ACCESO ENDOSCóPICO TRANSILíACO PARA ABORDAJE TRANSFORAMINAL EN L5-S1: REPORTE DE CASOS

ABSTRACT

Endoscopic surgery effectively treats foraminal pathologies of the spine; however, transforaminal access at L5-S1 can be challenging in patients with a high iliac crest, which hinders or prevents suprailac access. In this context, transiliac access emerges as a viable alternative. We report two cases of patients with foraminal/extraforaminal disc herniation at L5-S1 and a high iliac crest, who underwent transiliac endoscopic discectomy. Both patients showed significant improvement in pain intensity and functional disability, without complications or additional complaints related to iliac perforation. The results suggest that the transiliac endoscopic approach is a safe and effective option for treating foraminal and extraforaminal pathologies at L5-S1 in patients with a high iliac crest. Additional studies with more cases are necessary to confirm these findings and establish guidelines for its application. Level of Evidence IV; Case Report.

Keywords:
Endoscopic Surgical Procedures; Disk Herniation; Decompression; Surgical; Minimally Invasive Surgical Procedures; Neurosurgery.

RESUMO

A cirurgia endoscópica é eficaz no tratamento de patologias foraminais da coluna vertebral, porém o acesso transforaminal em L5-S1 pode ser desafiador em pacientes com crista ilíaca alta, que dificulta ou impede o acesso suprailíaco. Neste contexto, o acesso transilíaco surge como alternativa viável. Relatamos dois casos de pacientes com hérnia discal foraminal/extraforaminal em L5-S1 e crista ilíaca alta, submetidos à discectomia endoscópica transilíaca. Ambos apresentaram melhora significativa na intensidade da dor e na incapacidade funcional, sem complicações ou queixas adicionais relacionadas à perfuração do ilíaco. Os resultados sugerem que a abordagem endoscópica transilíaca é uma opção segura e eficaz para o tratamento de patologias foraminais e extraforaminais em L5-S1 em pacientes com crista ilíaca alta. Estudos adicionais com maior número de casos são necessários para confirmar estes achados e estabelecer diretrizes para sua aplicação. Nível de Evidência IV; Relato de Caso.

Descritores:
Procedimentos Cirúrgicos Endoscópicos; Hérnia de Disco; Descompressão Cirúrgica; Procedimentos Cirúrgicos Minimamente Invasivos; Neurocirurgia.

RESUMEN

La cirugía endoscópica es eficaz en el tratamiento de patologías foraminales de la columna vertebral; sin embargo, el acceso transforaminal en L5-S1 puede ser desafiante en pacientes con cresta ilíaca alta, lo que dificulta o impide el acceso suprailíaco. En este contexto, el acceso transilíaco surge como una alternativa viable. Presentamos dos casos de pacientes con hernia discal foraminal/extraforaminal en L5-S1 y cresta ilíaca alta, sometidos a discectomía endoscópica transilíaca. Ambos mostraron una mejora significativa en la intensidad del dolor y en la discapacidad funcional, sin complicaciones ni quejas adicionales relacionadas con la perforación del ilíaco. Los resultados sugieren que el abordaje endoscópico transilíaco es una opción segura y eficaz para el tratamiento de patologías foraminales y extraforaminales en L5-S1 en pacientes con cresta ilíaca alta. Se necesitan estudios adicionales con mayor número de casos para confirmar estos hallazgos y establecer directrices para su aplicación. Nivel de Evidencia IV; Reporte de Caso.

Descriptores:
Procedimientos Quirúrgicos Endoscópicos; Hernia Discal; Descompresión Quirúrgica; Procedimientos Quirúrgicos Mínimamente Invasivos; Neurocirugía.

INTRODUCTION

Endoscopic surgery has proven to be effective and safe in the treatment of foraminal pathologies of the spine. The transforaminal access at L5-S1 can pose a challenge for many surgeons, even with the advent of foraminoplasty¹. High and closed iliac crest, lower sacral inclination, lordosis reduction, and deformities can hinder or prevent the suprailiac foraminal access at the L5-S1 level. In these cases, the transiliac access option can be considered as an option for the treatment of foraminal or extra-foraminal diseases².

In this context, we aim to report two cases of transiliac accesses for transforaminal approach and treatment of foraminal and/or extra-foraminal pathologies.

CASES REPORT

This work was approved by the Research Ethics Committee (CAAE 70416223.8.0000.5487, opinion number 6.339.106), and all patients signed the Informed Consent Form (ICF).

The intensity of pain in patients was assessed using the visual analog scale (VAS) during the preoperative period (PRE), one month (PO1m), six months (PO6m), 12 months (PO12m), and 24 months (PO24m) of postoperative follow-up. The functional incapacity was assessed by the Oswestry Disability Index (ODI) in the same periods PRE, PO1m, PO6m, PO12m, and PO24m. The radiological exams performed were simple radiography, dynamic radiography, computed tomography (CT), and magnetic resonance imaging (MRI) of the lumbar segment.

The two procedures were performed with conscious sedation and local anesthesia. The marking of the entry point and the drilling of the iliac crest with percutaneous drills were performed with the aid of fluoroscopy. The working cannula was inserted through the transiliac bone tunnel, followed by the endoscope with a working channel of 4.3mm in diameter and 30 degrees of angulation. Continuous saline solution irrigation in the endoscope was performed with the saline elevated to 1.5m above the patient’s level. Foraminoplasty was performed with a cutting drill, and hemostasis was performed with retractable bipolar.

Case 1

44-year-old male patient complaining of pain in the right lower limb (RLL) and tingling for 60 days, with worsening pain intensity for the last 10 days. On physical examination, the patient was in an antalgic position in lateral decubitus with the RLL flexed. The VAS in the lumbar region was 8/10, and in the RLL was 9/10. The pre-operative ODI was 56%, denoting a severe disability. The Lasègue and Bragard tests were positive in the RLL at 45 and 30 degrees, respectively; in addition, a reduction in tactile sensitivity was observed in the right L5 dermatome. A lumbar spine MRI showed extruded foraminal and extra-foraminal disc herniation at the L5-S1 level on the right, with foraminal stenosis and compression of the right L5 root (Figures 1A, 1B). Surgical treatment was indicated after the failure of multimodal pharmacological clinical treatment and physical rehabilitation for 4 weeks. It was decided to perform endoscopic discectomy via the posterolateral (transforaminal) approach at the L5-S1 level on the right. The simple X-rays of the lumbar spine showed the presence of a high iliac crest, type III, in the anteroposterior (AP) position and profile, according to the classification of Patgaonkar et al.² (Figure 1C). For this reason, the transiliac access was chosen for the posterolateral transforaminal approach at L5-S1. The punch was performed 11cm from the midline, and the surgical time was 48 minutes. The patient was discharged from the hospital 4 hours after the procedure ended. The evolution of VAS and postoperative ODI can be observed in Table 1. There was no additional complaint of pain at the site of the iliac crest puncture. The location and path of the bony tunnel in the ilium on the CT can be observed in Figure 1.

Table 1
Pain intensity values by VAS and functional disability index by ODI in the PRE, PO1m, PO6m, PO12m, and PO24m periods of the reported cases.

		PRE	PO1m	PO6m	PO12m	PO24m
Case 1	lumbar VAS	8	3	1	2	2
	VAS in the RLL	9	4	2	1	1
	ODI	56%	14%	20%	16%	16%
Case 2	lumbar VAS	7	3	2	2	3
	VAS in the RLL	8	2	1	2	1
	ODI	48%	22%	18%	20%	18%

Figure 1
Axial (A) and sagittal (B) cuts of the MRI demonstrating right foraminal/extraforaminal disc herniation at L5-S1 (asterisk); path of the initial perforation of the ilium (C); postoperative CT cuts (D, E) showing the transiliac bony tunnel (red arrow).

Case 2

47-year-old male patient with pain in the RLL for 7 years, worsening for the past two months. I had already undergone a lumbar arthrodesis 20 years ago due to an L5 fracture. On physical examination, there was pain and hypoesthesia in the territory of the L5 dermatome on the right. The Lasègue maneuver in the RLL was positive at 45 degrees. The pain intensity on the VAS in the lumbar region was 7/10, and in the RLL, it was 8/10. The preoperative ODI was 48%, indicating a severe disability. The MRI of the lumbosacral region confirmed right foraminal stenosis at L5-S1, with foraminal stenosis and compression of the right L5 root (Figure 2). After the failure of multimodal pharmacological clinical treatment and physical rehabilitation with physiotherapy for 4 months, surgical treatment was indicated. The simple X-rays of the lumbar spine showed the previous lumbar arthrodesis from T12 to L5, Hartshill rods and Luke wires, and a high and closed iliac crest (Figures 2A/2B). It was then decided to perform the transforaminal transiliac access at L5-S1 on the right. The puncture was performed 12cm from the midline, followed by introducing the dilator and working cannula (Figures 2D/2E), and the surgical time was 52 minutes. The patient was discharged from the hospital 5 hours after the procedure ended. The evolution of VAS and postoperative ODI can be observed in Table 1. The patient reported pain at the site of the iliac perforation (VAS 2/10) for two weeks. Post-operative MRI can be observed in Figure 2F.

Figure 2
(A): AP incidence of the simple X-ray showing an angle less than 45 degrees between the lateral edge of the lumbar spine and a line that touches the iliac crest (red line); (B): profile incidence of the simple X-ray highlighting a high iliac crest, above the midline of the L5 pedicle (dashed arrow); (C): Preoperative MRI showing right L5-S1 foraminal stenosis (white arrow); (D): initial path of the iliac perforation by fluoroscopy; (E): positioning of the working cannula by fluoroscopy; and (F): Post-operative MRI showing improvement of foraminal stenosis (red arrow).

DISCUSSION

Surgical techniques for the spine have experienced significant advancements in recent decades, particularly with minimally invasive approaches such as spinal endoscopy. Endoscopic surgery of the lumbar spine has stood out not only for being less invasive but also for its versatility and ability to access different regions of the spine, regardless of the location of the pathology³.

Endoscopic lumbar discectomy has gained attention for offering less tissue trauma, reduced intraoperative bleeding, lower cost, and faster recovery compared to conventional techniques.⁴ Specific anatomical parameters are essential for surgical planning in lumbar endoscopy, especially at the L5-S1 level in cases of foraminal and extraforaminal pathologies ⁵,⁶.

The transforaminal approach at the L5-S1 level may be limited by the presence of a high iliac crest, which hinders adequate access and increases the risk of neural injury ⁷,⁸. As an alternative, transiliac access has been proposed as a viable technique for the treatment of foraminal and extraforaminal pathologies at this level⁹. This approach allows for better visualization and manipulation of the affected area, aligning with the principles of minimally invasive surgery by providing less morbidity and accelerated patient recovery⁹.

The cases presented in this study demonstrate that the transiliac endoscopic approach is safe, viable, and effective in treating foraminal and extraforaminal pathologies at L5-S1 in patients with high iliac crest. Neural decompression was successfully performed on both patients, with minimal blood loss and reduced surgical times, corroborating the findings of Osman et al.¹⁰ and Patgaonkar et al.² The patients showed significant improvement in pain levels, as assessed by the VAS, and reduction in functional disability measured by the ODI, results consistent with the existing literature ²,¹⁰-¹².

Osman and Marsolais’s pioneering study established the viability of the transiliac approach in cadaveric models, demonstrating the possibility of accessing the L5-S1 disc and foramen through the ilium without damaging important neural structures.¹³ Subsequently, Choi et al. reported two successful clinical cases using percutaneous endoscopic lumbar discectomy via the transiliac approach in patients with high iliac crest, emphasizing that this approach may be an alternative option when the conventional transforaminal route is unfeasible¹².

Bai et al. evaluated the short-term efficacy of the bone puncture technique in the transiliac approach for the treatment of intervertebral disc herniation at L5-S1, demonstrating satisfactory results in 19 patients treated with this technique¹⁴. Mahesha also reported positive results in 10 patients undergoing transiliac endoscopic discectomy, without the need for conversion to open approaches or occurrence of complications.

Although drilling the iliac bone in the transiliac approach may theoretically increase blood loss and cause intraoperative discomfort¹⁵, our cases did not present such complications, aligning with most of the studies analyzed. Wang et al. reported a case of dural injury in a series of patients treated with endoscopic resection of the transverse process for transforaminal access, indicating that complications, although rare, may occur and should be considered in surgical planning¹⁶.

The preoperative radiological evaluation and careful planning followed the criteria proposed by Patgaonkar et al.² are fundamental for the success of the transiliac approach. The surgical classification based on the relationship of the iliac crest with the vertebral body of L5 (types I, II, and III) aids in stratifying patients and choosing the most appropriate technique, optimizing clinical outcomes.

The limitations of this study include the small number of cases and the follow-up for up to 24 months. Although the initial results are promising, studies with larger samples and longitudinal follow-up are necessary to confirm the long-term efficacy and safety of the transiliac endoscopic approach in treating foraminal and extraforaminal pathologies at L5-S1.

CONCLUSION

In the reported cases, the transiliac endoscopic approach proved to be effective and safe for treating foraminal and extraforaminal pathologies at L5-S1 in patients with high iliac crest without causing additional pain related to iliac perforation. Careful surgical planning and appropriate patient selection are crucial for the technique’s success. Future studies with a larger number of cases are needed to validate these findings and establish clear guidelines for the application of this approach.

• Study conducted by the Clínica Atualli Spine Care, São Paulo, SP, Brazil.

REFERENCES

• ¹ Bergamaschi JP, de Oliveira Teixeira K, Soares TQ, de Araújo FF, Depieri GV, Lugão AF, et al. Extraforaminal Full-Endoscopic Approach for the Treatment of Lateral Compressive Diseases of the Lumbar Spine. J Pers Med. 2023;13(3):453. doi: 10.3390/jpm13030453.
  » https://doi.org/10.3390/jpm13030453.
• ² Patgaonkar P, Datar G, Agrawal U, Palanikumar C, Agrawal A, Goyal V, et al. Suprailiac versus transiliac approach in transforaminal endoscopic discectomy at L5-S1: a new surgical classification of L5-iliac crest relationship and guidelines for approach. J Spine Surg. 2020;6(Suppl 1):S145-54. doi: 10.21037/jss.2019.09.14.
  » https://doi.org/10.21037/jss.2019.09.14.
• ³ Choi JY, Park SM, Kim HJ, Yeom JS. Recent Updates on Minimally Invasive Spine Surgery: Techniques, Technologies, and Indications. Asian Spine J. 2022;16(6):1013-21. doi: 10.31616/asj.2022.0436.
  » https://doi.org/10.31616/asj.2022.0436.
• ⁴ Wirth F, Bergamaschi ECQA, Forti F da S, Bergamaschi JPM. Development of Indications for Endoscopic Spine Surgery: An Overview. Int J Transl Med. 2023;3(3):321-33. doi: 10.3390/ijtm3030023.
  » https://doi.org/10.3390/ijtm3030023.
• ⁵ Asano LYJ, Bergamaschi JPM, Dowling Á, Rodrigues LMR. Transforaminal Endoscopic Lumbar Discectomy: Clinical Outcomes and Complications. Rev Bras Ortop (Sao Paulo). 2020;55(1):48-53. doi: 10.1055/s-0039-1700822.
  » https://doi.org/10.1055/s-0039-1700822.
• ⁶ Moscatelli MA, Vargas AR, de Lima MV, Komp M, Silva RB, de Carvalho MOP, et al. New ipsilateral full endoscopic interlaminar approach for L5-S1 foraminal and extraforaminal decompression: technique description and initial case series. Neurosurg Rev. 2024;47(1):490. doi: 10.1007/s10143-024-02720-6.
  » https://doi.org/10.1007/s10143-024-02720-6.
• ⁷ Chen KT, Wei ST, Tseng C, Ou SW, Sun LW, Chen CM. Transforaminal Endoscopic Lumbar Discectomy for L5-S1 Disc Herniation with High Iliac Crest: Technical Note and Preliminary Series. Neurospine. 2020;17(Suppl 1):S81-7. doi: 10.14245/ns.2040166.060.
  » https://doi.org/10.14245/ns.2040166.060.
• ⁸ Kapetanakis S, Gkasdaris G, Angoules AG, Givissis P. Transforaminal Percutaneous Endoscopic Discectomy using Transforaminal Endoscopic Spine System technique: Pitfalls that a beginner should avoid. World J Orthop. 2017;8(12):874-80. doi: 10.5312/wjo.v8.i12.874.
  » https://doi.org/10.5312/wjo.v8.i12.874.
• ⁹ De Zavalía M, Gobbi E, Yeregui S. Hernia extraforaminal en el espacio L5-S1 tratada por abordaje transfacetario endoscópico. Presentación de un caso y nota técnica. Rev Asoc Argent Ortop Traumatol. 2024;89(1):70-5. doi: 10.15417/issn.1852-7434.2024.89.1.1856.
  » https://doi.org/10.15417/issn.1852-7434.2024.89.1.1856.
• ¹⁰ Osman SG, Sherlekar S, Malik A, Winters C, Grewal PK, Naayanan M, et al. Endoscopic trans-iliac approach to L5-S1 disc and foramen - a report on clinical experience. Int J Spine Surg. 2014;8:20. doi: 10.14444/1020.
  » https://doi.org/10.14444/1020.
• ¹¹ Sousa JM, Silva JL, Gamelas J, Guimarães Consciência J. Transiliac Endoscopic-Assisted L5S1 Intraforaminal Lumbar Interbody Fusion: Technical Considerations and Potential Complications. World Neurosurg. 2023;178:e741-9. doi: 10.1016/j.wneu.2023.07.153.
  » https://doi.org/10.1016/j.wneu.2023.07.153.
• ¹² Choi G, Kim JS, Lokhande P, Lee SH. Percutaneous endoscopic lumbar discectomy by transiliac approach: a case report. Spine (Phila Pa 1976). 2009;34(12):E443-6. doi: 10.1097/BRS.0b013e31817c4f39.
  » https://doi.org/10.1097/BRS.0b013e31817c4f39.
• ¹³ Osman SG, Marsolais EB. Endoscopic transiliac approach to L5-S1 disc and foramen. A cadaver study. Spine (Phila Pa 1976). 1997;22(11):1259-63. doi: 10.1097/00007632-199706010-00020.
  » https://doi.org/10.1097/00007632-199706010-00020.
• ¹⁴ Bai J, Zhang W, Wang Y, An J, Zhang J, Sun Y, et al. Application of transiliac approach to intervertebral endoscopic discectomy in L5/S1 intervertebral disc herniation. Eur J Med Res. 2017;22:14. doi: 10.1186/s40001-017-0254-0.
  » https://doi.org/10.1186/s40001-017-0254-0.
• ¹⁵ Mahesha K. Endoscopic transiliac approach to L5-S1 disc and foramen, technique and results. Journal of Orthopaedics and Allied Sciences. 2018;6(1):22-8. doi: 10.4103/joas.joas_59_17.
  » https://doi.org/10.4103/joas.joas_59_17.
• ¹⁶ Wang Z, Chen Z, Wu H, Wang X, Wang K, Duan W, et al. Treatment of high-iliac-crest L5-S1 lumbar disc herniation via a transverse process endoscopic transforaminal approach. Clin Neurol Neurosurg. 2020;197:106087. doi: 10.1016/j.clineuro.2020.106087.
  » https://doi.org/10.1016/j.clineuro.2020.106087.

Edited by

• Reviewed by:
  Aluizio Arantes

Publication Dates

• Publication in this collection
  13 Dec 2024
• Date of issue
  2024

History

• Received
  23 Oct 2024
• Accepted
  04 Nov 2024