Analysis of the causes of intraoperative conversion to open surgery for full endoscopic interlaminar disectomy

English Keywords:Lumbar disc herniation  Discectomy  Endoscopy  Interlaminar approach  Open surgery

English Abstract:

  【Abstract】 Objective：To analyze the causes of intraoperative conversion to open surgery for full endoscopic interlaminar disectomy，and to provide the correspondence prevention.Method：Retrospectively analyze 50 patients who had single-level lumbar disc herniation and undergone unilateral full endoscopic interlaminar discectomy from August 2008 to August 2010.The causes of intraoperative conversion to open surgery were summarized，and the effective preventions were also analyzed.Result：5 cases were converted to open surgery，with the conversion rate of 10%.There were 3 males and 2 females with the mean age of 36.2（range，29-44 years） years old.The average course duration was 58.4 days（range，35-105 days）.L5/S1 was involved in 4 cases and L4/5 in 1.The pathological type was lateral extrusion in 3 cases，paramedian extrusion in 1 and sequestration in 1.Of 5 cases of conversion to open surgery，misplacement of working portal was noted in 1 case；difficulty in dissection of nerve root and followed by hemostasis in 1 case who was complicated with dural injury；unavailability of exposure of nerve root in 3 cases.During the open procedure，the starting point of the nerve root at the dura lower than inferior laminar edge wa found.Therefore，partial removal of bony structures along lateral recesses was necessary in order to expose the nerve root.3 cases had lower extremity pain relieved and 2 alleviated after open surgery.Conclusion：The causes of intraoperative conversion to open surgery for full endoscopic interlaminar disectomy include imprecise placement of working portal，wrong indication and nerve root variation.The surgeon′s endoscopic experiences，right indications，and preoperative radiological examination of nerve root orientation can prevent full endoscopic interlaminar disectomy being converted to open surgery.