E98 Spine • Volume 32 • Number 2 • 2007 sive handling of the dorsal root ganglion, adhesions between the nerve root and the disc tissue, making the ENR immobile and presence of multiple fragments in EFDH. 2 We would like to address these objections as follows: As the working cannula in our technique enters the skin at a more medial position with a steep angle and is placed initially at a relatively inferior position near the superior endplate of caudal vertebra, the ENR has already moved laterally at this level and would not lie in the path of the needle trajectory. Ebraheim et al have also noted that, in case of extraforaminal disc herniations invading the axilla of the exiting root, the area available for cannula insertion increases due to the lateral displacement of the corresponding nerve root. 22 Second, the procedure being done under local anesthesia relies heavily on the patient feedback for any manipulation of the ENR. Regarding removal of the tip of superior facet and adhesions for adequate space creation, we would like to submit that from the initial safe position, as mentioned above, we gradually shift the working cannula by gentle rotatory movements and as soon as a part of the blue-stained herniated disc tissue is visualized, we use the Ho:YAG laser to release it from its surrounding adhesions. The side-firing laser works on a noncontact basis and does not need a wide space for manipulation. Once the fragment is released, it can be grasped from its tail and removed very easily as is done in microdiscectomy. The same technique is used in those cases where the herniated disc lies immediately anterior to and has jammed the nerve root. After the main fragment has been removed and the ENR is relatively mobile, we do advocate searching diligently for other free fragments, and it is easier to search for them under the endoscopic control as the angled view of the endoscope with a periscope-like maneuverability makes it possible to “look around the corners” and “look backward” for hidden fragments. 9 Several authors have reported a success rate ranging from 71% to 88% using the paraspinal muscle-splitting microsurgical technique for foraminal and extraforaminal disc herniations. 2–4,24 Lew et al reported a success rate of 85% using the endoscopic transforaminal technique for the mixed group of foraminal and extraforaminal disc herniations. 10 The satisfactory result rate of 92% in our series is comparable with these endoscopic technique studies for similar indications. However, the results may not be directly compared with those of open microsurgical technique due to the difference in indications in terms of bony pathology, as our technique is effective only for soft disc herniations. The most commonly reported complications with open microsurgical approach for these patients have been a 7% to 25% incidence of dysesthesia and 1% to 2% incidence of reflex sympathetic dystrophy. 2,24 The exact reason for these complications is still not known, but it is speculated to arise from excessive handling and mobilization of the exiting nerve root during open surgery. 2,11,24 We experienced 3 such cases (8%) of postoperative transient dysesthesia that resolved with various conservative measures. The use of laser and radiofrequency probe near the DRG, in addition to the working cannula, can lead to dysesthesia and these tools should be used very carefully. We have categorized the patients into satisfactory and unsatisfactory groups on the basis of percentage change in their ODI from preoperative level to judge the efficacy of any intervention at a glance. We think that ODI is currently widely used in many different languages and is an important universal indicator of the functional status of the patient. If the outcome analysis is done on the basis of percentage change in ODI from the baseline preoperative values and compared with that after the intervention, it could serve as a better objective criterion. In our study, we encouraged same-day or early discharge of the patients, but the decision for discharge was taken in consultation with patients, as most of these elderly patients were apprehensive returning home the same day after surgery. Although our technique has produced a high rate of favorable results, still there are some limitations with this approach. First, its use is restricted to soft disc herniations located in the extraforaminal region only. In the presence of associated bony stenosis in the extraforaminal/foraminal region contributing significantly to the patient’s symptoms, we would recommend an open microsurgical paraspinal approach for a wider and thorough decompression of the exiting nerve root. Similarly for combined intracanalicular and extraforaminal disc herniations that require exploration of the epidural space along with decompression of the far lateral fragments, the conventional transforaminal endoscopic technique with a more lateral skin entry point may be more useful as advocated by Yeung and Tsou 9 and Kambin. 12 Under such circumstances, our relatively medial skin entry point technique would restrict medial tilting of the working cannula, thus hindering the visualization and exploration of the epidural space, especially in the presence of a wide facet. At L5–S1, where the facet is larger compared with other lumbar levels, the skin entry point of the needle is more lateral. In case of high iliac crest, we select the needle entry point at the level of the disc but still the lateralmost point from the midline as permitted by the iliac crest. Another point worth mentioning here is that an experienced endoscopic surgeon would still be able to remove fragments from multiple locations without sticking to a fixed skin entry point. However, our technique being safer would be easier to adapt by young endoscopic surgeons, thus reducing the learning period. The study, not being double-blind and retrospective in nature, is another shortcoming of our work. Conclusion Percutaneous endoscopic discectomy using the “extraforaminal targeted fragmentectomy” approach is an effective and safe minimally invasive technique for the select
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