Incidental Durotomy in Open Versus Tubular Revision Microdiscectomy: A Retrospective Controlled Study on Incidence, Management, and Outcome.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: To compare the incidence, management, and outcome of incidental durotomy in revision microdiscectomy with open and minimal-access surgery. SUMMARY OF BACKGROUND DATA: Incidental durotomy occurs with a variable incidence of 3%-27% in spine surgery. The highest rate occurs in revision microdiscectomy. The intraoperative and postoperative management of dural tears varies in the literature and the definite impact on clinical outcome has to be clarified. METHODS: This is a retrospective study of medical records of 135 patients who underwent revision microdiscectomy, divided into 2 subgroups: OPEN (n=82) versus minimal-access surgery (MINI, n=53). Occurrence of intraoperative dural tears, intraoperative and postoperative management of durotomy, and clinical outcomes, according to MacNab criteria, were retrospectively examined. Statistical comparisons for categorical values between groups were accomplished using the 2-tailed Fisher exact test. P-values <0.05 were considered to be statistically significant. RESULTS: The incidence of durotomy in group OPEN was 19.5% (n=16/82) and in group MINI 17.0% (n=9/53) (P=0.822). The majority of durotomies (23/25) were repaired with an absorbable fibrin sealant patch alone. Postoperative cerebrospinal fluid fistula occurred only in 1 case of the OPEN group and was treated with lumbar drainage without the need for a reoperation. Patients with durotomy of the MINI group tended to have better outcome compared with those of the OPEN group without being statistically significant. CONCLUSIONS: The incidence of durotomy and postoperative cerebrospinal fluid fistula in lumbar revision microdiscectomy does not significantly differ between minimal-access and standard open procedures. The application of a fibrin sealant patch alone is an effective strategy for dural repair in revision lumbar microdiscectomy.

Minimally invasive tubular microdiscectomy for recurrent lumbar disc herniation.

OBJECTIVE: The aim of the study was to investigate the safety and efficacy of minimally invasive tubular microdiscectomy for the treatment of recurrent lumbar disc herniation (LDH). As opposed to endoscopic techniques, namely microendoscopic and endoscopic transforaminal discectomy, this microscopically assisted technique has never been used for the treatment of recurrent LDH. METHODS: Thirty consecutive patients who underwent minimally invasive tubular microdiscectomy for recurrent LDH were included in the study. The preoperative and postoperative visual analog scale (VAS) scores for pain, the clinical outcome according to modified Macnab criteria, and complications were analyzed retrospectively. The minimum follow-up was 1.5 years. Student t-test with paired samples was used for the statistical comparison of pre- and postoperative VAS scores. A p value < 0.05 was considered to be statistically significant. RESULTS: The mean operating time was 90 ± 35 minutes. The VAS score for leg pain was significantly reduced from 5.9 ± 2.1 preoperatively to 1.7 ± 1.3 postoperatively (p < 0.001). The overall success rate (excellent or good outcome according to Macnab criteria) was 90%. Incidental durotomy occurred in 5 patients (16.7%) without neurological consequences, CSF fistula, or negative influence to the clinical outcome. Instability occurred in 2 patients (6.7%). CONCLUSIONS: The clinical outcome of minimally invasive tubular microdiscectomy is comparable to the reported success rates of other minimally invasive techniques. The dural tear rate is not associated to higher morbidity or worse outcome. The technique is an equally effective and safe treatment option for recurrent LDH.

Minimally invasive redo discectomy for recurrent lumbar disc herniations.

The purpose of this systematic review is to investigate which minimally invasive techniques have been used for discectomy in recurrent lumbar disc herniation (LDH), to present the success and complication rates and to evaluate the advantages and limitations of each technique. Discectomy for recurrent LDH is accompanied by a higher morbidity rate compared with primary LDH. Because of the limited operating field, the majority of surgeons have been discouraged from utilising a minimally invasive approach for revision surgery. Minimally invasive techniques have gained ground in the treatment of primary LDH and an increasing number of patients are expressing interest in such techniques for the treatment of recurrent LDH. Microendoscopic discectomy (MED), endoscopic transforaminal and interlaminar discectomy (ETD and EID) have been used for treatment of recurrent LDH. The reported success rate is 60-95%. Full endoscopic techniques, especially ETD, showed favourable results concerning dural tear rates but have a demanding learning curve. The limitations of ETD include dislocated disc fragments or concomitant lateral recess stenosis, and MED is more effective in these instances. All three techniques have a low delayed instability rate. MED, ETD and EID are safe and efficient treatment options for surgical management of recurrent LDH with good success and low complication rates. At the same time, they offer the advantages of minimally invasive access.