Primary Lumbar Microdiscectomy Research Articles

Single-Level Unilateral Biportal Endoscopic versus Tubular Microdiscectomy: Comparing Surgical Outcomes and Opioid Consumption

Unilateral biportal endoscopic (UBE) microdiscectomy is an emerging minimally invasive surgery technique for treating symptomatic lumbar disc herniation. There is limited literature regarding outcomes. Here, we assess surgical outcomes and pain medication consumption for UBE vs. tubular lumbar microdiscectomy. This was a retrospective cohort study of adult patients undergoing primary, single-level UBE or tubular lumbar microdiscectomy surgery at a high-volume institution between 2018 and 2023. Variables of interest included operative time, complications and reoperations, as well as postoperative opioid and nonopioid pain medication consumption from discharge to 6 months. Opioid consumption was converted to morphine milligram equivalents. Standard statistical analyses were performed for comparative analyses. One hundred two patients-48 UBE and 54 tubular-were included. Average operative time (minutes) was higher for UBE patients (133.1 UBE vs. 86.6 tubular, P<0.001), which trended downward over time but did not reach statistical significance (P=0.07). There were no differences in complication or reoperation rates. Average daily MME was lower from discharge to 2-week follow-up in the UBE group (11.1 v. 14.1, P=0.02), but were comparative thereafter. Nonopioid medication prescription was lower in the UBE cohort from discharge to 2 weeks (70.8% vs. 92.6%, P=0.01) and 2 to 6 weeks (52.1% vs. 85.2%, P<0.001), with no significant differences thereafter. UBE microdiscectomy is associated with longer operating times. Both opioid and nonopioid pain medication consumption were lower for UBE patients during the initial postoperative period, perhaps owing to the less-invasive nature of the surgery.

122. Predictors and postoperative complication risks for revision discectomies following primary lumbar microdiscectomy

122. Predictors and postoperative complication risks for revision discectomies following primary lumbar microdiscectomy

Variability in Opioid Prescription Following Primary Single-Level Lumbar Microdiscectomy.

Study Design:Retrospective case series.Objectives:To evaluate the variability in opioid prescription following primary single-level lumbar microdiscectomy.Methods:We retrospectively reviewed consecutive patients who underwent primary single-level lumbar microdiscectomy. Only opioid-naïve patients ≥18 years old were included. Patients who had revision microdiscectomy, multilevel decompression, and/or any complication requiring prolonged hospital stay (>2 days) were excluded. The primary outcomes were the maximum daily dosage of opioids prescribed in morphine milligram equivalents (MME) and the number of pills prescribed (equivalent to 5 mg hydrocodone).Results:Between 2014 and 2019, 169 patients (90 men, 79 women) met inclusion criteria, with a mean age of 46.9 years. Surgery resulted in a statistically significant improvement in VAS (Visual Analogue Scale) score (6.4 to 2.5, P < .01). At discharge, 8 patients (4.7%) did not receive any opioid prescription. Of the remaining 161 patients, 1 patient (0.01%) received hydromorphone, 30 (18.6%) Percocet, 43 (26.7%) oxycodone, and 87 Norco (54.0%). The length of opioid prescription was 6.7 days. The maximum daily dosage of opioids prescribed was 70.4 MME (SD 32.1). The total number of pills prescribed was 89.4 (SD 54.7). Twenty-five patients (15.5%) received a refill prescription. Multivariate analysis demonstrated the operating service, prescriber, and hospital admission were statistically significant predictors of maximum daily MME. The prescriber and hospital admission were statistically significant predictors of total number of pills prescribed.Conclusions:We found significant variability in opioid prescription following primary single-level lumbar microdiscectomy. For standard spinal procedures like lumbar microdiscectomy, opioid-prescribing guidelines should be established to standardize postoperative pain management.

Recent trends in medicare utilization and reimbursement for lumbar spine fusion and discectomy procedures

Background ContextUnderstanding the scope of the volume and costs of lumbar fusions and discectomy procedures, as well as identifying significant trends within the Medicare system, may be beneficial in enhancing cost-efficiency and care delivery. However, there is a paucity of studies which analyze recent trends in lumbar fusion volume, utilization, and reimbursements. PurposeThis study seeks to define the costs of lumbar fusions and discectomy procedures and identify trends and variations in volume, utilization, and surgeon and hospital reimbursement rates in the Medicare system between 2012 and 2017. Study DesignRetrospective database study. Patient SampleMedicare Part A and Part B claims submitted for lumbar spine procedures from 2012 to 2017, as documented in the Centers for Medicare & Medicaid Services Physician and Other Supplier Public Use Files. Outcome MeasuresProcedure numbers and payments per episode. MethodsThis cross-sectional study tracked annual Medicare claims and payments to spine surgeons using publicly-available databases and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization rates (per 10,000 Medicare beneficiaries), and reimbursement rates, and to examine associations between county-specific and lumbar spine procedure utilization and reimbursements. ResultsA total of 772,532 lumbar spine procedures were performed in the Medicare population from 2012 to 2017, including 634,335 lumbar fusion surgeries and 138,197 primary lumbar discectomy and microdiscectomy single-level surgeries. There was a 26.0% increase in annual lumbar fusion procedure volume during the study period, with a compound annual growth rate (CAGR) of 4.7%. Lumbar discectomy/microdiscectomy experienced a 23.5% decrease in annual procedure volume (CAGR, −5.2%). Mean Medicare surgeon reimbursements for lumbar fusions nominally decreased by 3.7% from $767 in 2012 to $738 in 2017, equivalent to an inflation-adjusted decrease of 11.4% (CAGR, −0.7%). Mean Medicare payments for lumbar discectomy and microdiscectomy procedures nominally increased by 16.3% from $517 in 2012 to $601 in 2017, equivalent to an inflation-adjusted increase of 6.9% (CAGR, 3.1%). ConclusionsThis present study found the volume and utilization of lumbar fusions have increased since 2012, while lumbar discectomy and microdiscectomy volume and utilization have fallen. Medicare payments to hospitals and surgeons for lumbar fusions have either declined or not kept pace with inflation, and reimbursements for lumbar discectomy and microdiscectomy to hospitals have risen at a disproportionate rate compared to surgeon payments. These trends in Medicare payments, especially seen in decreasing allocation of reimbursements for surgeons, may be the effect of value-based cost reduction measures, especially for high-cost orthopedic and spine surgeries.

Gender differences in the 3-month utilization of nonoperative therapies prior to primary lumbar microdiscectomy

Patients with lumbar intervertebral disc herniation classically trial a brief course of conservative management prior to microdiscectomy surgery. Gender differences have previously been identified in the selection and symptomatic response to commonly-utilized nonoperative treatments. However, whether gender differences exist in the degree and cost of nonoperative therapy in this cohort remains unknown. Therefore, the purpose of this study was to assess for gender differences in the utilization and costs of nonoperative therapy in patients diagnosed with symptomatic lumbar intervertebral disc herniation 3-months prior to undergoing microdiscectomy. Medical records from adult patients diagnosed with a lumbar intervertebral disc herniation undergoing index microdiscectomy procedures from 2007 to 2017 were collected retrospectively from a large insurance database. The utilization of nonoperative therapy within 3-months after initial lumbar herniation diagnosis was determined. A total of 13,106 patients (55.4% Males) underwent index microdiscectomy. Male patients were more likely to fail conservative management and opt for surgery (Males: 2.9% vs. Females: 1.8%, p < 0.0001). A greater percentage of female patients utilized muscle relaxants (p = 0.0049), lumbar epidural steroid injections (p = 0.0007), and emergency department services (p = 0.001). The total direct cost of conservative treatment prior to microdiscectomy was $13,205,924, with males accountable for $7,457,023 (56.5%). When normalized by number of patients utilizing the respective therapy, males used fewer units of NSAIDs (males: 84.2 pills/patient; females: 97.3 pills/patient) and muscle relaxants (males: 77.5 pills/patient; females: 89.0 pills/patient). These results suggest that gender differences exist in the utilization of nonoperative therapies for the management of a lumbar intervertebral herniated disc prior to microdiscectomy surgery.

30-day complication rates and patient-reported outcomes following day case primary lumbar microdiscectomy in a regional NHS spinal centre

Advances in surgical and anaesthesia technique have reduced length of stay for lumbar discectomy. Current evidence suggests that daycase surgery is associated with improved patient satisfaction, faster recovery, reduced infection rates and financial savings. We present our microdiscectomy daycase protocol, together with 30-day postoperative complication rates and patient reported outcomes in an NHS setting. We retrospectively studied all patients that met a locally agreed daycase protocol for lumbar microdiscectomy and were operated upon and discharged on the same calendar day between 1 March 2013 and 31 December 2015. A total of 134 patients underwent primary daycase microdiscectomy (70 males, 64 females). The cohort had a mean age of 41 years (range 16-82 years). Some 96% (n=129) were single-level procedures, 93% were unilateral (n=125) and 81% (n=109) took place at either L4/L5 or L5/S1. All patients were discharged on the same day as admission and operation. Four patients re-presented to hospital within 30 days and three were discharged from the emergency department within four hours following a clinical review. One patient required an inpatient stay for a washout of a superficial postoperative infection. Significant improvements (P<0.05) were found postoperatively for back pain and leg pain on self-reported visual analogue scores and Oswestry Disability Index. In this study, we present a safe and effective protocol for day case lumbar microdiscectomy. Our 30-day postoperative complication rate of under 1% is comparable to that of traditional inpatient primary lumbar microdiscectomy. Patient-reported outcome measures revealed significant improvement in both pain and functional scores.

Friday, September 28, 2018 3:00 PM–4:00 PM abstracts: optimizing lumbar disc surgery: 218. Patients undergoing revision microdiscectomy for recurrent lumbar disc herniation experience worse clinical outcomes and more reoperations compared to patients undergoing a primary microdiscectomy

BACKGROUND CONTEXT When conservative measures fail, lumbar disc herniation has been shown to be successfully treated by a microdiscectomy surgery. The percentage of patients that necessitate revision surgery within 2years varies between 0.5% and 24% in literature, with recurrent herniation being the most common presentation.However, in the setting of a revision discectomy surgery for a recurrent disc herniation, outcomes can be more difficult to predict. Some studies with smaller patient populations and diverse outcome protocols have not found significant clinical outcome differences between these two patient populations. Other studies have begun to elucidate differences at 1 year after surgery. PURPOSE The goal of this study is the compare the demographics and outcomes of patients undergoing primary lumbar microdiscectomy surgery for a disc herniation and those undergoing a revision microdiscectomy surgery for a recurrent disc herniation. STUDY DESIGN/SETTING Retrospectivec cohort series. PATIENT SAMPLE We performed a retrospective analysis of patients who underwent a primary or revision lumbar microdiscectomy between 2009 and 2015 by one of two senior orthopaedic spine surgeons. Patients were excluded from analysis if they had any previous lumbar surgery (other than a microdiscectomy at the recurrent disc herniation level), were under 18 years of age at the time of surgery, or had postoperative follow up less than 3 months. Patients were divided into two groups: those undergoing a primary surgery for a lumbar disc herniation (primary) and those undergoing a revision procedure for a recurrent disc herniation (recurrent). OUTCOME MEASURES Patient reported outcomes were obtained in the form of Oswestry Disability Index (ODI) scores, Visual Analog Scales (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey (SF-12) scores, and the Veterans Rand 12-Item Health Mental and Physical Survey (VR-12) scores. Patients were also surveyed about their expectations and satisfactions following surgery. METHODS Baseline patient characteristics were compared using chi-squared analysis and independent sample t-tests for categorical and continuous data, respectively. Bivariate and multivariate regressions were subsequently used to compare clinical outcomes between procedure groups. Multivariate analyses controlled for differences in baseline patient characteristics. RESULTS Overall, 296 consecutive patients who fulfilled our inclusion criteria were assessed. The patients in the recurrent group were significantly younger than those in the primary group (44.6±12.7 vs. 53.2±16.2 years; p CONCLUSIONS Patients who presented with symptoms related to a recurrent lumbar disc herniation underwent surgery significantly sooner than those patients who underwent a primary lumbar microdiscectomy for a disc herniation. At 2 years following surgery, patients that underwent a revision lumbar microdiscectomy for a recurrent disc herniation reported significantly worse patient outcomes following surgery. These patients that underwent revision surgery were also significantly less satisfied and felt as though their results did not exceed nor meet their expectations of the procedure. Revision rates were also significantly higher in patients undergoing a revision lumbar microdiscectomy. Although three-quarters or patients will not require a repeat operation following a revision microdiscectomy, preoperative educations should be clearly communicated regarding the elevated risk of a subsequent reherniation and/or worse back pain as well as expectations following this revision procedure.

Friday, September 28, 2018 3:00 PM–4:00 PM abstracts: optimizing lumbar disc surgery: 215. Patients presenting with a lumbar far-lateral herniated nucleus pulposus can expect similar postoperative outcomes to those presenting with a central or paracentral herniation

BACKGROUND CONTEXT A far lateral herniated nucleus pulposus (HNP) consists of 7%-12% of all disc herniations. 'Far lateral' is often used to describe a lumbar disc herniation that compresses the exiting nerve root at the same level, lateral to the neural foramen. The far lateral disc herniations have been described to elicit radicular leg pain that is more severe than a central or paracentral lumbar disc herniation due to direct compression of dorsal root ganglion, and are said to have a more acute onset in their clinical symptoms. However, literature does not provide much description of the comparative postoperative outcomes between those presenting with a far lateral HNP and those with a central or paracentral herniation. PURPOSE The goal of this study is to examine the pre- and postoperative outcomes between patients presenting with a central or paracentral versus a far lateral HNP. STUDY DESIGN/SETTING Retrospective cohort series. PATIENT SAMPLE We performed a retrospective cohort analysis of patients who underwent a primary lumbar microdiscectomy between 2009 and 2015 by one of two senior orthopaedic spine surgeons for lumbar spinal stenosis. Patients were excluded from analysis if they had any previous lumbar surgery, an unstable spondylolisthesis, were under 18 years of age at the time of surgery, or had postoperative follow up less than 3 months. Patients were divided into two groups based on the location of the HNP (central or paracentral versus far-lateral). OUTCOME MEASURES Patient reported outcomes were obtained in the form of Oswestry Disability Index (ODI) scores, Visual Analog Scales (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey (SF-12) scores, and the Veterans Rand 12-Item Health Mental and Physical Survey (VR-12) scores. METHODS Baseline patient characteristics were compared using chi-squared analysis and independent sample t-tests for categorical and continuous data, respectively. Bivariate and multivariate regressions were subsequently used to compare clinical outcomes between procedure groups. Multivariate analyses controlled for differences in baseline patient characteristics. RESULTS Overall, 212 consecutive patients who fulfilled our inclusion criteria were assessed. Average follow-up was 24.14 months (range 3–78 months). There were 191 patients who presented with a central or paracentral HNP, while 21 patients presented with a far-lateral HNP. There were no significant differences in the demographic variables between these two groups. Patients with a far lateral disc herniation presented with a trend towards a shorter duration of symptoms prior to surgery (24.5 vs. 31.5 months; p=.052). On multivariate analysis, patients with a far lateral disc herniation presented with significantly lower SF-12 mental (52.14±13.49 vs. 55.1±6.55; p=.034) and physical scores (24.76±7.5 vs. 36.9±11.1; p=.008). Similarly, the far-lateral disc herniation patients also presented with significantly lower VR-12 mental (47.2±12.8 vs. 56.9±7.0; p=.024) and physical scores (25.8±8.7 vs.39.38±11.8; p=.005). However, postoperatively, all patients have similar SF-12 and CR-12 survey scores. The improvement in ODI score was significantly lower in the patients presenting with a far lateral disc herniation (7.8±15.1 vs. 28.3±21.5; p=.002). No significant difference in re-operation rates was found (p=.236). CONCLUSIONS Patients presenting with far lateral disc herniations present with significantly lower SF-12 mental and physical scores as well as lower VR-12 mental and physical scores. However, at approximately 2 years following a lumbar microdecompression surgery, both groups of patients express similar successful outcomes, including SF-12 and VR-12 survey scores. Re-operation rates are similar between the two groups. Despite compression at the site of the dorsal root ganglion and the reported greater difficulty in addressing far lateral disc herniations, patients presenting with these far lateral disc herniations can expect similar outcomes to those patients present with herniations in the central or paracentral region.

Letter to the Editor concerning “Ribosomal PCR assay of excised intervertebral discs from patients undergoing single-level primary lumbar microdiscectomy.’’ by Alamin TF, Munoz M, Zagel A, et al.: Eur Spine J 2017

Letter to the Editor concerning “Ribosomal PCR assay of excised intervertebral discs from patients undergoing single-level primary lumbar microdiscectomy.’’ by Alamin TF, Munoz M, Zagel A, et al.: Eur Spine J 2017

Ribosomal PCR assay of excised intervertebral discs from patients undergoing single-level primary lumbar microdiscectomy.

To determine the presence of infectious microorganisms in the herniated discs of immunocompetent patients, using methodology that we hoped would be of higher sensitivity and specificity than has been reported in the past. Recent studies have demonstrated a significant rate of positive cultures for low virulent organisms in excised HNP samples (range 19-53%). These studies have served as the theoretical basis for a pilot trial, and then, a well done prospective randomized trial that demonstrated that systemic treatment with antibiotics may yield lasting improvements in a subset of patients with axial back pain. Whether the reported positive cultures in discectomy specimens represent true positives is as yet not proven, and critically important if underlying the basis of therapeutic approaches for chronic low back pain. This consecutive case series from a single academic center included 44 patients with radiculopathy and MRI findings of lumbar HNP. Patients elected for lumbar microdiscectomy after failure of conservative management. All patients received primary surgery at a single spinal level in the absence of immune compromise. Excised disc material was analyzed with a real-time PCR assay targeting the 16S ribosomal RNA gene followed by amplicon sequencing. No concurrent cultures were performed. Inclusion criteria were as follows: sensory or motor symptoms in a single lumbar nerve distribution; positive physical examination findings including positive straight leg raise test, distributional weakness, and/or a diminished deep tendon reflexes; and magnetic resonance imaging of the lumbar spine positive for HNP in a distribution correlating with the radicular complaint. The PCR assay for the 16S rRNA sequence was negative in all 44 patients (100%). 95% CI 0-8%. Based on the data presented here, there does not appear to be a significant underlying rate of bacterial disc infection in immunocompetent patients presenting with radiculopathy from disc herniation.

British Spine Registry (BSR) PROMS compliance and results after primary lumbar microdiscectomy

British Spine Registry (BSR) PROMS compliance and results after primary lumbar microdiscectomy

British Spine Registry (BSR) PROMS compliance and results after primary lumbar microdiscectomy

British Spine Registry (BSR) PROMS compliance and results after primary lumbar microdiscectomy

Is the rate of re-operation after primary lumbar microdiscectomy affected by surgeon grade or intra-operative lavage of the disc space?

Study design. Retrospective audit of consecutive patients. Objective. To investigate the re-operation rate following elective primary lumbar microdiscectomy and to determine whether principal surgeon grade and/or disc space lavage is a factor in recurrence. Summary of background data. Recurrent herniation of disc material following lumbar microdiscecomy surgery is one of the commonest complications of the procedure. Any reduction in the number of revision microdiscectomies performed per year would have a significant impact on patients’ lives and on the health service economy. We undertook this study to ascertain whether principal surgeon grade and/or disc space lavage has an impact in reducing the re-operation rate. Methods. We undertook a retrospective audit of patients who underwent elective primary lumbar microdiscectomy, over a 3-year period (n = 971). Results. The overall re-operation rate for primary elective microdiscectomy was 3.8%, consistent with the published literature. The relative risk of re-operation in patients primarily operated by registrar surgeons was 1.2 fold the risk in patients operated by consultants (95% CI: 0.62, 2.35) although not statistically significant (p = 0.568). The risk of re-operation in the ‘non lavage’ group was 2.15 times the risk in the ‘lavage’ group (95% CI: 0.63, 7.34), but it did not reach significance (p = 0.222). Conclusions. Principal surgeon grade and intervertebral disc lavage have not been found conclusively to be factors in the rate of recurrence. This information is useful to reassure patients that their outcome from such surgery is not dependent on the grade of surgeon performing the operation. There is a possible trend towards intervertebral disc lavage reducing the rate of recurrence.

Preoperative “group and save” in lumbar microdiscectomy: is it necessary?

"Group and save" (type and screen) is commonly requested preoperatively in lumbar microdiscectomy. On average, less than 100 ml of blood is lost during lumbar microdiscectomy, and blood transfusion guidelines and resuscitation practice recommend that no transfusion would be required in almost all healthy patients with less than 750 ml of blood loss. The authors performed an audit of 319 consecutive lumbar microdiscectomies to determine if the practice of group and save can be justified. A telephone survey of the United Kingdom (UK) neurosurgical units to establish current UK neurosurgical practice was also conducted. A telephone survey of all UK neurosurgical units and an audit of all patients who underwent primary lumbar microdiscectomy at our institution over a period of 2 consecutive years was performed. The health records of all patients were retrieved and critically reviewed. Information about hemoglobin measurements before and after surgery, group and save, and blood transfusion were collected. Thirty-two UK neurosurgical units were surveyed by telephone, with a 100% response rate. Group and save was commonly performed prior to lumbar microdiscectomy in 28 units (87.5%). The records of 319 consecutive patients who underwent lumber microdiscectomy were reviewed. All patients had group and save prior to lumbar microdiscectomy. No patient required a blood transfusion during or after surgery. The mean decrease in hemoglobin concentration was 0.8 g/dl in 121 patients who had postoperative hemoglobin measurements. Blood transfusion and hemoglobin decrease following lumbar microdiscectomy is exceptionally rare. Group and save and postoperative hemoglobin measurements are therefore nonessential in all patients undergoing lumbar microdiscectomy, with potentially significant cost savings from not performing these tests.

Bacteriologic Culture of Excised Intervertebral Disc From Immunocompetent Patients Undergoing Single Level Primary Lumbar Microdiscectomy

A consecutive case series from a single center of patients undergoing primary microdiscectomy for lumbar herniated nucleus pulposus (HNP) who received microbiologic laboratory culture of excised disc material. To determine the prevalence of positive bacterial cultures in the disc material of immunocompetent patients without diabetes mellitus or other immune compromise. The intradiscal space is a physiologically tenuous environment in terms of oxygen tension, pH, and vascularity. This space may be susceptible to indolent infections with an unknown effect on the pathogenesis of HNP. This case series included 52 patients with radiculopathy and magnetic resonance imaging positive for HNP who elected for lumbar microdiscectomy after failure of conservative management. All patients received primary surgery at a single spinal level in the absence of diabetes mellitus, systemic steroid use, chemotherapy, other immune compromise, or prior lumbar surgery. Excised disc material was sent for routine bacterial culture. No special culture techniques were used to improve the yield of positive cultures. Cultures were positive in 10 patients (19.2%). Propionibacterium acnes was the sole organism isolated in 7 (13.5%), with Peptostreptococcus and Staphylococcus species accounting for the remainder. There were 24 women (46.2%) and 28 men (53.8%) with a mean age of 43.9 years (SE 1.8). Duration of symptoms was greater than 12 weeks in 35 patients (67.3%). Onset of symptoms was insidious in 22 patients (42.3%), sudden in 16 (30.8%), and the history was unclear in the remainder. Prior epidural steroid injection was received by 17 patients (32.7%), and 11 patients had a history of smoking (21.2%). None of these variables was significantly different in patients with positive and negative cultures (P >0.05). P. acnes was isolated by routine laboratory culture of excised disc material in 13.5% of immunocompetent patients undergoing primary single level discectomy for radiculopathy with lumbar HNP; other organisms were isolated in 6% of patients. Diagnostic level of evidence III.

Results of Bacterial Culture from Surgically Excised Intervertebral Disc in 52 Patients Undergoing Primary Lumbar Microdiscectomy at a Single Level

The pathogenesis of lumbar disc disease is complex. At the molecular and cellular levels, a cascade has been elucidated which involves inflammatory mediators and cytokines, structural matrix proteins and their fragments, and proteases and their inhibitors. Mechanical and genetic factors also play a role in the spectrum of disc disease, from herniated nucleus pulposus (HNP) to end stage degenerative disc disease with loss of height. Less attention has been given to possible microbial pathogens as an etiologic factor in HNP.

Outcomes of microdiscectomy for treatment of recurrent lumbar disc herniation

Objective To evaluate the outcomes of microdiscectomy for treatment of recurrent lumbar disc hemiations. Methods There were 18 cases of recurrent lumbar disc berniations accepted microdiscectomy (reoperation group), compared with 30 cases of primary lumbar microdiscectomy (primary group). Operating time, blood loss and length of hospital stay were compared between two groups. MacNab criteria were used to evaluate the outcomes. Results Operating time was a mean of 75 min in reoperation group, 52 min in primary group. Blood loss of reoperation group was 70 ml, 50ml in primary group. Length of hospital stay was 8.5d in reoperation group, 6.5d in primary group. There were one dural tear, two Ls root lesions and 5 more numbness reoperation group, but recovery all patients. There were one dural tear in primary group. 17 cases got follow-up mean 12.1 months in reoperation group and 29 cases in primary group mean 11.8 months. The results demonstrated 88.2% success rate in reoperation group and 93.1% in primary group. There was no significant dif-ference in two groups (P ＞ 0.05). Conclusion Outcomes of Lambar mierodisceetomy with mini-open for treatment of recurrent lumbar disc herniations are similar to primary lumbar mierodiscectomy. Key words: Lumbar vertebrae; Lumbar disc herniation; Microdiscectomy

Lumbar microdiscectomy under epidural anesthesia: a comparison study

Background context Lumbar microdiscectomy is most commonly performed under general anesthesia, which can be associated with several perioperative morbidities including nausea, vomiting, atelectasis, pulmonary aspiration, and prolonged post-anesthesia recovery. It is possible that fewer complications may occur if the procedure is performed under epidural anesthesia. Purpose To investigate the safety and efficacy of epidural anesthesia in elective lumbar microdiscectomies. Study design A prospective study evaluating the relative morbidities associated with epidural anesthesia and general anesthesia for lumbar microdiscectomy. Patient sample Forty-three patients scheduled for primary lumbar microdiscectomy. Two cohorts were formed and were studied separately; one observational of all the 43 patients, and a second cohort of 17 patients who agreed to enter in the randomized trial. Outcome measures The clinical outcome was determined by the presence of postoperative pain, the absence of anesthesia-related complications, and the overall postoperative recovery. Methods This was a prospective study. With institutional review board approval, 43 consecutive patients were enrolled in the study. However, only 17 patients agreed to be randomized to receive either general or epidural anesthesia for the procedure; the remaining 26 patients selected the type of anesthesia of their preference. Recorded data for all patients included: age; total surgical time; occurrence of nausea, vomiting, atelectasis, or cardiopulmonary complication; ability to arise out of bed on the day of surgery; and the total number of inpatient hospital days. Postoperative pain and satisfaction were assessed only in the randomized cohort. Results There were a total of 43 patients, with a mean age of 38.1 years. The patients undergoing epidural anesthesia were marginally older than those undergoing general anesthesia. The epidural and general anesthetic groups were not different with respect to surgical time, pain assessed with a linear visual analogue scale, hospital stay, or the likelihood of arising out of bed on the day of surgery. There were no major cardiopulmonary complications in either group. Patients with epidural anesthesia had significantly less nausea and vomiting. Conclusions Epidural anesthesia as an alternative to general anesthesia has shown less postoperative nausea and vomiting in lumbar microdiscectomy. Nevertheless, given the small number of patients, this study should be considered as preliminary, showing small differences in minor potential complications.

Revisional lumbar microdiscectomy: an analysis of operative findings and clinical outcome

Forty-one consecutive patients who underwent a revision microlumbar exploration for recurrent or persistent sciatica were reviewed retrospectively to analyse the operative findings and assess the clinical outcome following surgery. Thirty-three (80%) patients were found to have a recurrent intervertebral disc protrusion at the previous site, two patients had a disc herniation at a new site, one had severe perineural scarring, two had lateral recess stenosis, one patient had undergone previous exploration at an incorrect site and in two patients no cause for ongoing symptoms was found. Nineteen of the 33 patients with a re-prolapse presented with persistent or recurrent sciatica within 1 year of their first operation. The other 14 patients presented with a late re-prolapse (after 1 year) and their clinical outcome was better than for those patients with an early re-prolapse (12/14 vs 11/19 satisfactory result, respectively). The result of operating on patients with a late re-prolapse was comparable to the 80-95% satisfactory outcomes following primary lumbar microdiscectomy reported by other authors.