Comparison of Quality of Life Between Men and Women Who Underwent Transforaminal Percutaneous Endoscopic Discectomy for Lumbar Disc Herniation

INTRODUCTION

Lumbar disc herniation (LDH) is more common in the lower levels of the lumbar spine and is responsible for the presence of the lumbosacral radicular syndrome, which is a frequently observed problem.¹ The major symptoms of this syndrome are low back pain and sciatica following a dermatomal pattern from below the knee to the feet and toes. Low back pain with sciatica is the main cause of disability and is one of the most prevalent diseases affecting the majority of population on both health and socioeconomics.^2–4 When not treated for a long time, it is responsible for relapses of pain and high frequency of work absence.⁵ Low back pain is more frequent in men, but the prevalence is quite high in both sexes.⁶ Other symptoms of the lumbosacral syndrome may include unilateral spasm of the paraspinal muscles, gait deformity, limited forward flexion, muscle weakness, and reflex changes.^7,8

In patients with persistent or progressive symptoms after 6 to 12 weeks of conservative treatment (by analgesics or by physical therapy), surgery is indicated. The surgical approach to treatment of LDH includes open discectomy and microdiscectomy.^9,10 Although discectomy is the most frequently performed spinal surgery, it has been replaced by microdiscectomy, which is now the “gold standard” method.^11–13 Improvements in the use of optics and surgical instruments have led to the use of full-endoscopic minimally invasive surgical procedures. As a result, endoscopy has become popular among spinal surgeons over the last decades and can be performed with a posterior or posterolateral approach.¹⁴ The search for newer surgical techniques to achieve the aims of minimally invasive surgery, including limited skin incisions and decreased muscle damage, has made transforaminal percutaneous endoscopic discectomy (TEPD) a promising minimally invasive surgical procedure recently.

Transforaminal percutaneous endoscopic discectomy approaches the epidural space through the Kambin's triangle and combines the benefits of endoscopy (direct visualization, reduced trauma, reduced blood loss, shorter hospital stays, less pain, quicker recovery, and postoperative morbidity) with optimal exposure of the intervertebral space and preservation of the dorsal musculature, the vertebrae, and the ligamentous structures.^15–17 No paraspinal muscle is cut or detached from the insertion. The minimal tissue damage during TEPD could make a difference in effectiveness, faster rehabilitation, and thus lower costs for society. There are several studies comparing the safety and efficacy of TEPD with those of microdiscectomy; however, there is no comparison between men and women who underwent this minimally invasive surgery. Men, in contrast to women, have generally greater muscle mass but slightly higher body mass index (BMI), which, hypothetically, could alter the postsurgical recovery. Thus, we considered that some differences based on gender characteristics might exist between our 2 groups. This study examines our experience using this technique to improve early recovery after surgery treating LDH in accordance with sex.

PATIENTS AND METHODS

Surgical Technique

The TEPD was performed under local anesthesia and mild sedation. All patients were monitored in terms of blood pressure, pulse rate, oxygen saturation, and electrocardiographic signals. Patients were positioned at the lateral decubitus position, lying down on the opposite site in order for the lesion to face upward.¹⁴ After disinfection of the surgical field, local anesthesia was initially performed at the needle entry site. The needle was placed through the Kambin's triangle 11 cm from the midline, under fluoroscopic technique (Figure 1).^14,18 After verification of the level, mild sedation and analgesia were provided with fentanyl (ampule) because the enlargement of the neural foramen is painful. The compliance of the patients was affected during the sequential passage of 3 different size reamers (5.5, 6.5, 7.5 mm, Joymax System). The cannula and the endoscope were then placed and the nerve root was secured. Subsequently, the discectomy was performed with graspers (Figure 2). The patients were monitored for the following hour in the wards and then mobilized.

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Figure 1

Anteroposterior (right) and lateral (left) intraoperative fluoroscopic images of the guide wire placed at the level where the disc herniation is present.

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Figure 2

Intraoperative endoscopic visualization of the annular opening of the working channel. With the rongeur it is possible to remove the herniated disc material.

RESULTS

Group A consisted of 38 (50%) male patients, including those who had been diagnosed with LDH, and group B consisted of 38 (50%) female patients, including those who had been diagnosed with LDH. Regarding the LDH level, 21 (27.6%) was presented at L3-L4, 40 (52.6%) at L4-L5 and 15 (19.7%) at L5-S1 (Table 1). Of 76 patients, 52 (68.4%) patients were ≤63 years old, whereas the other 24 (31.4%) were >63 years old (mean ±  SD = 56.5 ±  12.1 years). The two subpopulations (men and women) do not have statistically significant differences, something which is important because the groups under comparison have similar starting characteristics (Table 2).

The mean BMI was 29.3 ±  1.2 for men and 28.8 ± 1.1 for women. The mean operative time was 32.1 ± 2.3 minutes and the blood loss limited. All patients underwent the procedure successfully without conversion to open surgery. The patients were discharged 1 day after surgery. There were no intraoperative complications. There were few postoperative complications and they were temporary. One patient presented hypoesthesia on the lower extremity, and 2 presented neurogenic dysfunction, which was absent after 1 month. In addition, 2 furcal nerves were found in 2 patients. None of the patients underwent a revision surgery.

All selected patients successfully reached the end of the follow-up. Thus, the percentage of the 1-year follow-up is 100%.The increase of all 8 scaled scores of SF-36 between 2 chronological phases and in all intervals was statistically significant (P ≤ .05) in the total of patients and in each group separately (Table 3). Physical role functioning, bodily pain, general health, vitality, social role functioning, emotional role functioning, and mental health scores were higher in every visit for the 2 groups, but the change between groups was not significant (P > .05).

Group B (women) had a significantly higher increase in the PF score in the 3 months after TPED (P = .023) and in the interval 6 weeks to 3 months (P < .001) compared with group A (men). However, in the intervals 3 to 6 months and 3 to 12 months, group A presented a significantly higher increase in the PF score (P = .025 and P = .007, respectively) compared with group B. At the end of a year follow-up, physical function was increased by 35.2 (±5.9) in group A and 35.9 (±5.1) in group B (P < .001).

Regarding the graphic representations, the SF-36 scores preoperatively and at 6 months and 1 year postoperatively showed statistically significant increases in all 8 domains for men and women separately and in the total number of patients (Figures 3 and 4). Changes in SF-36 scores at 6 months and 1 year compared with before surgery showed no statistically significant differences for all 8 domains between men and women (Figure 5).

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Figure 3

The 36-Item Short Form Health Survey (SF-36) scores preoperatively, at 6 months, and at 1 year postoperatively, related to gender. Abbreviations: PF, physical function; RP, role physical; BP, bodily pain; GH, general health; V, vitality; SF, social function; RE, role emotional; MH, mental health.

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Figure 4

The 36-Item Short Form Health Survey (SF-36) scores in total sample, preoperatively, at 6 months and at 1 year postoperatively. Abbreviations: PF, physical function; RP, role physical; BP, bodily pain; GH, general health; V, vitality; SF, social function; RE, role emotional; MH, mental health.

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Figure 5

Change in 36-Item Short Form Health Survey (SF-36) scores at 6 months and at 1 year compared with before surgery, related to gender. Abbreviations: PF, physical function; RP, role physical; BP, bodily pain; GH, general health; V, vitality; SF, social function; RE, role emotional; MH, mental health.

DISCUSSION

There has been an increasing interest in the effect of sex in scientific and clinical research. We considered this to be an interesting comparison, because men, in contrast to women, have generally greater muscle mass but slightly higher BMI. Hypothetically, this could play a significant role in the postsurgical recovery of men and women. The results of this study showed statistically significant improvement in health-related quality of life, including physical role functioning, bodily pain, general health, vitality, social role functioning, emotional role functioning, and mental health, in every postoperative visit for both male and female patients. In general, the change between the 2 groups was not significant. Thus, TPED does not present differences between men and women.

With regard to the PF domain, women had a significant higher increase in the PF score in the 3 months after TPED and in the interval 6 weeks to 3 months, compared with men; however, men presented significantly a higher increase in the PF score in the last three quarters of the 1-year follow-up, in contrast to women. Thus, this difference is counterpoised over time and does not have major clinical importance. The PF domain includes many activities, some vigorous (such as running, lifting heavy objects), others moderate (such as moving a table, carrying groceries, climbing stairs, bending, walking). Men included in this study probably had more demanding physical functioning in their normal routine than the women and also a slightly higher BMI, which leads to more difficulty and a limitation of typical activities. Nevertheless, men presented a significantly higher increase of PF score in the intervals 3 to 6 months and 3 to 12 months when compared with women. An explanation for this could be the fact that at this point, the recovery of the nerve root is completed and the greater muscle mass of men contributes to improvement in former daily activities.

There are several studies that indicate the role of TEPD as a minimally invasive surgery with multiple advantages, especially in single-level herniations.^15–17,20 However, studies of TEPD for LDH describing its safety and efficacy are limited. There are two systematic reviews which conclude that TPED appears to be a safe and effective intervention for LDH and has similar clinical outcomes compared with conventional open microdiscectomy.^21,22 Even more promising results come from a recent systematic review and meta-analysis that compared endoscopic discectomy versus open microdiscectomy and found a significantly higher satisfaction rate in patients who underwent endoscopic discectomy.²³ Statistically significant and clinically relevant sex differences were found in other studies also. In a relative study for LDH treated with microdiscectomy, at 1-year follow-up, women reported a higher degree of postoperative back and leg pain along with less improvement regarding disability and some aspects of quality of life; however, the surgical effect was similar.²⁴

The present study has several limitations. Due to the design, there was no proper control group because the objective of this study was not to emphasize the possible advantages of TEPD over other procedures but to present its early results on the improvement of the quality of life of patients. We did not want to include the widely used Oswestry Low Back Pain Questionnaire and Visual Analog Scale because we consider SF-36 to be a multi-scaled questionnaire that is more complete, including emotional and mental sections. Furthermore, it would increase the significance of our study results if we considered designing 1 more year of follow-up to achieve a 2-year period. This did not happen because we wanted to present our early clinical findings on these patients.

Even though several studies regarding TPED for the treatment of LDH exist, none of them has investigated the differences of the improvement of the health-related quality of life between men and women. Transforaminal percutaneous endoscopic discectomy is associated with many advantages in that it preserves the biomechanics of the lumbar spine, offers stability to the operated and adjacent level, and reduces traumatization of the supportive paraspinal tissues. On the basis of our findings, TEPD seems to be a secure and efficient technique with significant improvement of the quality of life of men and women during the 1-year follow-up for the treatment of LDH. Indeed, few differences were observed between the 2 groups; however, those had minor clinical impact. Nevertheless, this topic should be further researched with high-quality randomized controlled trials that also assess cost-effectiveness.