Comparative Study of the Outcomes of Endoscopic Unilateral Laminotomy for Bilateral Decompression (ULBD) With Destandau Technique and Microscopic ULBD: A Randomized Double-Blinded Study of 685 Patients

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J Minim Invasive Spine Surg Tech. 2024;9(Suppl 1):S70-S76

Publication date (electronic) : 2023 December 1

doi : https://doi.org/10.21182/jmisst.2023.00829

Paresh Chandra Dey¹, Nishit Palo^,2, Abhishek Shukla³

¹Department of Orthopaedics, KIMS, Bhubaneswar, Odisha, India

²Department of Orthopaedics, Santosh Medical College & Hospital, Ghaziabad, India

³Department of Orthopaedics, Holy Family Hospital, Delhi, India

Corresponding Author: Nishit Palo Department of Orthopedics, Santosh Medical College, Ghaziabad, Uttar Pradesh, India Email: nishit_palo@yahoo.com

Received 2023 May 23; Revised 2023 July 2; Accepted 2023 July 27.

Abstract

INTRODUCTION

Spinal canal stenosis remains the most common indication for spine surgery in elderly [1]. Patients with degenerated spine and neurological symptoms often have dysfunction [2], dissatisfaction and poor quality of life (QoL). Their output in daily routine activities suffer, rendering them dependent on others for assistance.

Patients with spinal canal stenosis often present with back pain and radiating pain. Treatment options range from medications to surgery. Recently minimal invasive techniques like unilateral laminotomy for bilateral decompression (ULBD) performed using endoscope system or microscope are being preferred [3]. The newer techniques involve use of enhanced optics, instrumentation, and artificial intelligence [4], thereby improving precision and limited tissue dissection. Research articles have reported early clinical recovery with endoscopic procedures, but studies comparing ULBD performed by with endoscopic system (Destandau technique) and microscope are very few.

Spine instability and back pain have been reported post microscopic ULBD [5]. Endoscopes on other hand offer excellent magnification, illumination and 4K clarity through a single portal. It is important to assess patient-related outcome scores to understand the impact of surgical procedure on patient’s QoL.

This study was initiated to compare the clinical outcomes (surgical timing, blood loss, hospital stay, MacNab scores, Oswestry Disability Index (ODI), 36-item Short Form health survey [SF-36] scores, and complications) in patients undergoing spinal decompression performed by endoscope with Destandau technique and microscopes. Secondly to document patient specific parameters like visual analogue score (VAS), QoL, side changing ability postoperatively.

MATERIALS AND METHODS

A prospective multicenter study performed at 3 centers in Bhubaneswar, India from May 2012 to February 2019 on 685 patients undergoing single-level decompression for spinal canal stenosis. Patients were randomized into 2 groups; randomization was done by computer generated number.

3. Surgical Technique

All peocedures were performed under general anesthesia and standard radiolucent operating table was used for all surgeries.

1) Group 1: modified chest knee position (Figure 1)

Figure 1.

(A) Patient position for endoscopic unilateral laminotomy for bilateral decompression (modified chest knee position). (B) Placement of Destandau endoscopic system (Tube) with skin markings.

Destandau Endospine System (Karl Storz, Tuttlingen, Germany) comprising of endospine tube, trocar, and working insert was used (Figure 1). Levels were marked with use of localization device, skin incision (15–20 mm) was marked 5 mm besides midline, and Mayo scissors were used to dissect the aponeurosis. Periosteum elevator was used to dissect the paravertebral muscles from spinous process and superior lamellae to expose the interlaminar window. Laminotomy was performed under vision to expose underlying dural sac and nerve root.Discectomy was performed under vision (Figure 2), adequacy was confirmed by pushing saline and visual confirmation by endoscope in disc cavity. Further, over-the-top decompression was performed on contralateral side (Figure 3).

Figure 2.

Intraoperative field: secured nerve root and discectomy.

Figure 3.

Intraoperative endoscopic view. (A) Ligamentum flavum (opposite side, green arrow) and Kerrison punch (blue arrow). (B) Nerve root (opposite side, yellow arrow) and ligamentum flavum (blue arrow).

2) Group 2: patient placed in Wilson Frame

A 30- to 50-mm midline incision was marked. Aponeurosis along with paravertebral muscles were dissected as usual. Laminotomy was performed followed by the microscopic soft tissue decompression. Medial facet and ligamentum flavum were dissected under microscopic visualization by high-speed drill and a curette. Discectomy was performed followed by over-the-top decompression on contralateral side.

RESULTS

A total of 685 patients who underwent single-level spinal canal ULBD were included in this study. Endoscopic ULBD with Destandau technique (group 1) had 343 patients and microscopic ULBD (group 2) had 342 patients. The demographic and preoperative characteristics of the patients were statistically similar (Table 1).

Table 1.

Demographic and preoperative patient data

The radiologic outcomes and surgical data are shown in Table 2 and clinical outcomes are shown in Table 3. The degree of horizontal displacement was lower in group 1 than group 2 (0.34%±0.21% vs. 2.45%±1.61%, p<0.001). Postoperative pain and ODI expressed in percentage were significantly improved in both groups (p<0.001). There was a significant difference in the improvement of pain (VAS) at 1 week after operation between the groups 1 and 2 (42.28%±3.20% vs. 50.15%±6.82%, p<0.001). Authors observed a significant difference in hospital stay. Group 1 patients were comfortable and discharged early (1±0.2 vs. 1.8±0.8, p<0.01).

Table 2.

Comparison of variables between groups 1 and 2

Table 3.

Comparison of clinical outcomes between endoscopic decompression and microscopic decompression

There was a significant difference in ODI at 1 week after operation between the groups 1 and 2 (42.28±3.20 vs. 50.15±6.82, p<0.001). However, there was no significant difference in ODI at 1 month after operation and 1 year after operation in both groups.

There was a significant difference in the modified MacNab score at 1 week after operation between the groups 1 and 2 (85.30% vs. 88.44%, p<0.001). However, the difference was not significant from 1-month to 1-year postsurgery.

There was no significant difference in dura expansion (336.61±58.32 vs. 318.10±64.72, p=0.21), operation time (59.20±8.14 vs. 68.45±12.07, p=0.04) and blood loss the groups 1 and 2 (52.42±9.82 vs. 60.32±14.20, p=0.02).

At 1-week postsurgery; there was significant improvement 30-second chair stand test results (3.4±0.13 vs 5.6±2.41, p<0.001) and 10-meter walk test (1.0±2.15 vs 0.55±3.23, p<0.001) (Table 4) values in group 1. SF-36 physical health component subscale score also had significant improvement at 1-week postsurgery in group 1 (48.20±8.46 vs. 74.48±0.54, p<0.001). Furthermore, 92% of patients were able to change sides while in bed at 1-week postsurgery. Overall QoL and patient satisfaction was better in group 1. Claudication distance improved significantly after decompression for both the groups (Table 4).

Table 4.

Functional outcomes between groups 1 and 2

There were 22 cases (6.43%) of cerebrospinal fluid leak in group 2 and 12 (3.50%) cases in group 1, all of which were treated with conservative treatment including bed rest, fluid replacement, and medications. Surgical site infection occurred in 8 cases (2.3%) in group 2 and 5 (1.45%) in group 1 were treated with antibiotics. At 1-year follow-up, 6 patients (1.74%) in group 1 and 11 patients (3.21%) in group 2 had recurrence.

DISCUSSION

There is often a poor radiographical and clinical correlation in spine pathologies. The treatment must be tailored to accommodate patient’s needs. Patients not responding to conservative therapy warrant surgical decompression [6]. Minimally invasive surgical procedures are being done for patients suffering from lumbar canal stenosis worldwide [7].

Conventional or open decompressive laminectomy has been done over the years and is an established procedure. Although it offers better hand control and manipulative freedom; but it involves extensive soft tissue stripping and larger surgical scar. Conventional surgical management of lumbar canal stenosis has been open decompressive laminectomy. This is a useful procedure with enhanced hand manipulative control, but it involves stripping and retraction of paraspinal muscles along with removal of spinous process and lamina, this can lead to iatrogenic instability [8], adhesions [9], scarring and para spinal muscle atrophy thus persistent back pain.

Minimal invasive techniques aim at precise dissection and specific soft tissue removal, limiting removal of important structures. This allows early rehabilitation, better clinical outcomes [10] and cosmesis. Variety of surgeries are being performed using minimally invasive techniques like lumbar discectomy [11], foraminal decompression, spinal fusion, and deformity correction [12]. The patients underwent surgery with minimally invasive techniques. The advantages of minimally invasive approach undergo minimal tissue trauma, blood loss, shorter operative time, lesser hospital stays, perineural fibrosis [13,14], and have less analgesic requirement postoperatively.

Endoscopic spinal instrumentation has revolutionized spine surgeries. It offers clear magnified 4K vision, illumination, and magnification with precise soft tissue removal. Learning curve is high in endoscopic surgery due to small working channel and space, which can improve with training and experience.

In our study, patients presented with back pain, radiating pain, and combination of both. Group 1 patients had a shorter hospital stay, less blood loss, and operative time. They also had significantly better VAS scores and ODI at 1 week postoperatively. Later, scores were still better for group 1 but were not statistically significant between the 2 groups.

Significantly improved modified MacNab scores were observed in group 1 at 1-week, 1-month, and 3-month follow-ups (Table 3). At 1 year postoperatively, these scores were better for endoscopic group but not statistically significant.

At 1 week postoperatively, group 1 patients tolerated surgical procedure better and had improved functional scores (30-second chair stand test and 10-meter walk test) postoperatively with better SF-36 scores; the physical health component results were statistically significant (Table 4). However, the statistical difference between the 2 procedures was not significant in SF-36 mental health component scores.

Postoperatively; 92.65% patients could change side by themselves in group 1 as compared to 87.72% in group 2. These results could be interpreted as a significant improvement in the QoL of patients in group 1 at 1-week postsurgery. Improved claudication distance was seen in both the groups postsurgery owing to effective decompression.

CONCLUSION

Group 1 patients have better clinical and functional outcomes within 3 months of surgery compared to group 2 patients. They have improved QoL with shorter hospital stays, better SF-36 scores and self-side changing ability.

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