Yong Ahn

Percutaneous endoscopic lumbar discectomy for recurrent disc herniation: surgical technique, outcome, and prognostic factors of 43 consecutive cases.

Study Design. A retrospective study of 43 consecutive patients who underwent percutaneous endoscopic lumbar discectomy for recurrent disc herniation. Objectives. To evaluate the efficacy of endoscopic discectomy for recurrent disc herniations and to determine the prognostic factors affecting surgical outcome. Summary of Background Data. Repeated open discectomy with or without fusion has been the most common procedure for a recurrent lumbar disc herniation. There have been no reports published on the feasibility and prognostic factors of the endoscopic discectomy for recurrent disc herniation. Methods. The inclusion criteria were recurrent disc herniations at the same level, regardless of side, with a pain-free interval longer than 6 months after the conventional open discectomy. Posterolateral endoscopic laser-assisted disc excisions were performed under local anesthesia. Results. The mean follow-up period was 31 months (24–39 months). Based on the MacNab criteria, 81.4% showed excellent or good outcomes. The mean visual analog scale decreased from 8.72 ± 1.20 to 2.58 ± 1.55 (P <0.0001). In our series, better outcomes were obtained in patients younger than 40 years (P = 0.035), patients with duration of symptoms of less than 3 months (P = 0.028), and patients without concurrent lateral recess stenosis (P = 0.007). Conclusions. Percutaneous endoscopic lumbar discectomy is effective for recurrent disc herniation in selected cases. The posterolateral approach through unscarred virgin tissue can prevent nerve injury and could preserve the spinal stability. Both foraminal and intracanalicular portions can be decompressed simultaneously.

CHARITE versus ProDisc: a comparative study of a minimum 3-year follow-up.

Study Design. A retrospective study. Objectives. To evaluate and compare clinical and radiologic outcomes of the CHARITÉ and ProDisc. Summary of Background Data. There is no clinical report comparing CHARITÉ and ProDisc. Methods. Among a total of 61 patients who underwent total disc replacement, 57 patients followed more than 3 years were enrolled. The CHARITÉ was used in 33 patients and ProDisc in 24. MRI follow-up was possible in 52 patients. Clinical and radiologic data including range of motion (ROM) and facet degeneration of the replaced segment, and degeneration of the disc at the adjacent level were evaluated. Results. Mean percentage improvement of Oswestry Disability Index (ODI) score was 78.9% in the CHARITÉ group and 75.8% in ProDisc group. The mean improvement of the Visual Analogue Scale (VAS) pain score was 72% in the CHARITÉ and 74.2% in ProDisc. There was no statistical difference between 2 groups in improvement rates either of the ODI scores and VAS scores. Degradation of the facets was seen in 36.4% of the CHARITÉ and 32% of the ProDisc. Degradation of disc degeneration at the adjacent level above the index level was seen in 19.4% in the CHARITÉ and 28.6% in the ProDisc. The degradation rates of facet joints and disc at adjacent segment between the 2 groups were not significantly different. Segmental ROM of the replaced segments was well preserved, but ROM of L5–S1 of the ProDisc was significantly less than that of the CHARITÉ. Conclusions. While clinical outcomes of both CHARITÉ and ProDisc groups were fairly good, the facet joint of the index level and the disc at the adjacent level showed an aggravation of the degenerative process in a significant number of patients, regardless of the device used, raising concerns of possible late consequences of total disc replacement, especially regarding facet arthrosis and adjacent segment disease.

Operative failure of percutaneous endoscopic lumbar discectomy: a radiologic analysis of 55 cases.

Learning Objectives: After participating in this CME activity, the obstetrician/gynecologist should be better able to: 1. Accurately counsel patients on the risks and benefits of initiating hormone therapy (HT) for vasomotor symptoms (VMS). 2. Apply current evidence to select appropriate HT for treatment of VMS in uncomplicated postmenopausal women. 3. Compare the risks and benefits of HT for special subpopulations of menopausal patients, such as women with a history of breast cancer, BRCA mutation carriers, those with hypertension, women older than 65 years, and those at a high risk for or with a history of venous thromboembolism.

Comparison of percutaneous endoscopic lumbar discectomy and open lumbar microdiscectomy for recurrent disc herniation.

OBJECTIVE The purpose of this study was to compare clinical and radiological outcomes of percutaneous endoscopic lumbar discectomy (PELD) and open lumbar microdiscectomy (OLM) for recurrent disc herniation. METHODS Fifty-four patients, who underwent surgery, either PELD (25 patients) or repeated OLM (29 patients), due to recurrent disc herniation at L4-5 level, were divided into two groups according to the surgical methods. Excluded were patients with sequestrated disc, calcified disc, severe neurological deficit, or instability. Clinical outcomes were assessed using Visual Analogue Scale (VAS) score and Oswestry Disability Index (ODI). Radiological variables were assessed using plain radiography and/or magnetic resonance imaging. RESULTS Mean operating time and hospital stay were significantly shorter in PELD group (45.8 minutes and 0.9 day, respectively) than OLM group (73.8 minutes and 3.8 days, respectively) (p < 0.001). Complications occurred in 4% in PELD group and 10.3% in OLM group in the perioperative period. At a mean follow-up duration of 34.2 months, the mean improvements of back pain, leg pain, and functional improvement were 4.0, 5.5, and 40.9% for PELD group and 2.3, 5.1, and 45.0% for OLM group, respectively. Second recurrence occurred in 4% after PELD and 10.3% after OLM. Disc height did not change after PELD, but significantly decreased after OLM (p = 0.0001). Neither sagittal rotation angle nor volume of multifidus muscle changed significantly in both groups. CONCLUSION Both PELD and repeated OLM showed favorable outcomes for recurrent disc herniation, but PELD had advantages in terms of shorter operating time, hospital stay, and disc height preservation.

Radiation Exposure to the Surgeon During Percutaneous Endoscopic Lumbar Discectomy : A Prospective Study

Study Design. A prospective study. Objective. The purpose of this study was to determine the radiation dose to which the surgeons are exposed during percutaneous endoscopic lumbar discectomy (PELD) and to calculate the allowable number of cases per year. Summary of Background Data. Transforaminal PELD is a minimally invasive technique for soft disc herniation. Minimal invasiveness can be achieved through the use of fluoroscopy and endoscopy. The radiation dose to the surgeon during PELD is unknown. Methods. The occupational radiation dose absorbed by 3 spinal surgeons performing 30 consecutive PELDs (33 levels) during a 3-month period was evaluated. Transforaminal PELDs were performed according to the standard technique. The radiation exposure of the neck, chest, arm, and both hands of the surgeons was measured. Occupational exposure guidelines of National Council on Radiation Protection & Measurements were used to calculate the allowable number of procedures per year. Results. The mean operation time was 49.8 minutes, and the mean fluoroscopy time was 2.5 minutes. No significant correlations were found between operation time and fluoroscopy time. The calculated radiation doses per operated level were as follows: neck, 0.0785 mSv; chest, 0.1718 mSv; right upper arm, 0.0461 mSv; left ring finger, 0.7318 mSv; and right ring finger, 0.6694 mSv. The protective effects of a lead collar and lead apron were demonstrated by the reduction of the radiation dose by 96.9% and 94.2%, respectively. Therefore, with regard to whole-body radiation, 5379 operations can be performed per year using a lead apron, whereas only 291 operations can be performed without using a lead apron. Moreover, 1910 operations can be performed within the occupational exposure limit for the eyes (150 mSv), and 683 operations can be performed within the occupational exposure limit for the hands (500 mSv). Conclusion. Without radiation shielding, a surgeon performing 291 PELDs annually would be exposed to the maximum allowable radiation dose. Given the measurable lifetime radiation hazards to the surgeon, the use of adequate protective equipment is essential to reducing exposure during PELD.

A comparison of unilateral and bilateral laminotomies for decompression of L4-L5 spinal stenosis.

Study Design. A retrospective review of clinical and radiographic data was performed at a single institution. Objectives. To compare clinical and radiologic outcomes between unilateral and bilateral laminotomies for bilateral decompression in patients with L4–L5 spinal stenosis. Summary of Background Data. Laminotomy has been shown to be comparable with laminectomy with the advantage of potentially maintaining more stability by preserving more of the osseous structures. However, the comparison between unilateral and bilateral laminotomies is available only for short-term follow-up. Methods. Fifty-three patients at one institution having decompres–sive surgery for L4–L5 spinal stenosis, including grade 1 degenerative spondylolisthesis without instability, were entered into this study with a minimum of 3-year follow-up. Clinical outcomes were assessed with visual analog scale for back and leg pain and the Oswestry disability index. Radiographic measurements were performed and included translational motion, angular motion, and epidural cross-sectional area. Results. The average age of the patients was 62.4 years (range: 31–82). The mean follow-up period was 49.3 months (range: 40–61). Clinical outcomes and complication rates were similar in both groups. Intraoperative blood loss and operative time were less in the unilateral laminotomy group. Radiographically, the amount of increased translational motion was significantly increased in the bilateral laminotomy group (P = 0.012), but the amount of increased angular motion was not significantly different (P = 0.195) between the two groups. Postoperative radiographic instability was detected more frequently in bilateral laminotomy group than in the unilateral group, without statistical significance. Conclusions. Both unilateral and bilateral laminotomies provide sufficient decompression of spinal stenosis and excellent pain reduction. However, unilateral laminotomy can be performed with shorter operative times and less blood loss. Radiologically, the use of a unilateral laminotomy induces less translational motion increase after surgery; thus, it may reduce the risk of late instability when compared with a bilateral laminotomy.

Postoperative retroperitoneal hematoma following transforaminal percutaneous endoscopic lumbar discectomy

OBJECT The purpose of this study was to demonstrate the clinical characteristics of postoperative retroperitoneal hematoma (RPH) following transforaminal percutaneous endoscopic lumbar discectomy (PELD) and to discuss how to prevent the complication of unintended hemorrhage. METHODS The medical records of 412 consecutive patients treated with transforaminal PELD between January 2005 and May 2007 were reviewed. A total of 4 patients (0.97%) experienced symptomatic postoperative RPH. The clinical outcomes were evaluated using the visual analog scale and the Oswestry Disability Index. RESULTS The common symptom in all patients with a hematoma was inguinal pain. The mean hematoma volume was 527.9 ml (range 53.3-1274.1 ml). Two patients with massive diffuse-type RPHs compressing the intraabdominal structures required open hematoma evacuation performed by general surgeons, and the other 2 patients with small, localized RPHs of < 100 ml were treated conservatively. The mean follow-up period was 21.3 months (range 13-29 months). The mean visual analog scale score for radicular leg pain improved from 7.6 to 1.8 and that for back pain improved from 4.3 to 2. The mean Oswestry Disability Index improved from 58.8 to 9.1%. The preoperative symptoms improved after the second treatment without significant neurological sequelae in all patients. CONCLUSIONS Although transforaminal PELD is a minimally invasive and safe procedure, the possibility of RPH should be kept in mind. Adequate technical and anatomical considerations are important to avoid this unusual hemorrhagic complication, especially in the patient with underlying medical problems or previous operative scarring. A high index of suspicion and early detection is also important to avoid the progression of the hematoma.

Motor Palsy After Posterior Cervical Foraminotomy: Anatomical Consideration

BACKGROUND Motor palsy is a serious complication that can result from cervical surgery. We introduced cases of motor palsy after posterior cervical foraminotomy (PCF) and consider cervical anatomy. METHODS Between January 2007 and August 2010, 133 PCFs were performed on 106 consecutive patients with radiculopathy caused by foraminal stenosis or posterolateral disc herniation. RESULTS Three of 133 (2.3%) levels that underwent PCF developed a motor palsy. Two cases involved the C5 nerve root, and one case involved the C6 nerve root. The cause of the C5 palsy may have been excessive retraction, whereas the cause of the C6 palsy may have been thermal damage caused by drilling. The rate of C5 palsy (22.2%) was much higher than that seen with other nerves. Anatomically, the C5 nerve root is thinner and covers the entire intervertebral disc at a relatively sharper angle than the other nerve roots. The removal of an extruded disc at C4-5 forces more excessive retraction of the C5 nerve root. CONCLUSIONS Although PCF is a good alternative treatment with minimal morbidity for cervical radiculopathy, surgeons should keep in mind the possibility of motor palsy, especially at C4-5.

Laser-assisted posterior cervical foraminotomy and discectomy for lateral and foraminal cervical disc herniation.

OBJECTIVE Posterior cervical foraminotomy and discectomy (PCFD) is regarded as an effective treatment option for cervical radiculopathy. However, limited exposure of the disc space is one of its major disadvantages. To address this problem, we used a CO(2) laser for sophisticated decompression. The purpose of this study was to demonstrate the clinical outcomes of laser-assisted PCFD and to discuss the benefits of laser use. METHODS A total of 47 consecutive patients with cervical radiculopathy were treated with PCFD. Among them, 24 patients were treated with laser-assisted PCFD, and the remaining 23 patients were treated with conventional PCFD. After standard posterior cervical microscopic foraminotomy, a microscopic CO(2) laser was used for selective discectomy in the laser PCFD group. Clinical data were compared with a minimum 2-year follow-up period. Clinical outcomes were evaluated using the visual analogue scale (VAS), Neck Disability Index (NDI), and modified MacNab criteria. RESULTS The clinical outcomes of the two groups were similar. The mean VAS score for radicular arm pain improved from 7.42 to 1.83 in the laser PCFD group and from 8.30 to 1.65 in the conventional PCFD group. The mean NDI improved from 47.00% to 10.46% in the laser PCFD group and from 53.86% to 10.02% in the conventional PCFD group. The rate of excellent or good outcomes was 87.5% for the laser PCFD group and 86.9% for the conventional PCFD group. A significant difference between the groups was found for intraoperative bleeding. The laser PCFD group had significantly lower estimated blood loss values than did the conventional PCFD group (p<0.05). CONCLUSIONS Laser-assisted PCFD is an efficacious surgical option for treating lateral cervical disc herniation. The pinpoint accuracy of the laser scalpel facilitates sophisticated decompression within a limited surgical field, and may reduce the risk of intraoperative bleeding and neural damage.

Failed anterior lumbar interbody fusion due to incomplete foraminal decompression

BackgroundAnterior lumbar interbody fusion (ALIF) has gained widespread popularity for spinal disorders requiring fusion. The purpose of this study was to analyze ALIF failures.MethodsThe medical records of 223 patients treated with ALIF between January 2007 and June 2008 were retrospectively reviewed. Patients with unfavorable outcomes, including subsequent posterior decompression at the index level or poor outcomes after ALIF were identified based on clinical and radiological findings. The patients were divided into two groups: an unfavorable group and a favorable group. Preoperative clinical and radiological factors for each group were statistically analyzed.ResultsTwo hundred of the 223 patients were enrolled in this study. Thirteen (6.5%) of 200 patients resulted in unfavorable outcome. Four patients (2%) of them underwent posterior decompressive surgery. The main cause of unfavorable outcomes was incomplete decompression of the foraminal stenosis. Unfavorable outcomes were obtained in patients with the level of L5-S1 (p = 0.036), higher body mass index (p = 0.048), higher percentage of slippage (p = 0.024), and severe facet arthropathy (p = 0.013). However, there was no difference in preoperative disc height, foraminal size, facet angle, facet tropism, or preoperative visual analog scale for back and leg pain, the Oswestry disability index, symptom duration, and fusion rate between the two groups.ConclusionBased on these results, posterior decompression and fusion may be considered for obese patients with the level of L5-S1, high-grade spondylolisthesis, or severe facet arthropathy. On the other hand, ALIF can be used an effective alternative treatment in many spinal disorders requiring fusion.