Microendoscopic Discectomy (MED) for Lumbar Disc Herniation / 한양의대학술지

Lumbar disc herniation is one of the most common disorders and its current surgical standard is a microsurgical discectomy. The microendoscopic discectomy (MED) was initially developed in 1997 by Foley and Smith and it is a minimally invasive surgical technique. This article discusses the technique, outcome and complications of this procedure. MED is performed by a muscle splitting approach using a series of tubular dilators with consecutively increasing diameters. The original endoscopic procedure is modified with microscope which has led to the development of the Microscopic Endoscopic Tubular Retractor System (METRX, Medtronic Sofamor Danek, Memphis, TN). A tubular retractor is inserted over the final dilator, and then the microscope is placed inside the tubular retractor instead of the endoscope. And then microdiscectomy is performed in the usual fashion via tubular retractor. Clinical outcomes by modified MacNab criteria were revealed excellent to good results in up to 95% of the patients. Average return to work period was within 1 month. Complications included nerve root injury, dural tear, and recurrent disc herniations. MED is at least as effective as microdiscectomy for the treatment of lumbar disc herniations with regard to long-term outcomes. MED can be performed safely and effectively with a smaller incision, resulting in a shortened hospital stay and faster return to work.

Retroperitoneal Hematoma Secondary to Terminal Branch of Segmental Artery Injury during Intertransverse Discectomy through Paramedian Muscle Splitting Approach

A 47-year-old man underwent the surgery of intertransverse discectomy through paramedian muscle splitting due to extraforaminal type of far lateral disc herniation at 4th-5th interspace of lumbar vertebrae. The authors encountered the terminal branch of the segmental artery that traversed the extruded disc around the dorsal root ganglion during the sugery. We coagulated the artery by a bipolar coagulator and cut the artery for the discectomy. There was no active bleeding during the surgery. However, the patient suffered from abdominal, right leg and flank pain at the first postoperative day. The follow-up magnetic resonance imaging revealed a retroperitoneal hematoma at the operation site. The patient underwent removal of the retroperitoneal hematoma. We identified the cause of bleeding as the rupture of coagulated terminal branch of the segmental artery around the dorsal root ganglion. The retroperitoneal hematoma was evacuated completely. The ruptured artery was clipped by a small metal clip, and his symptoms subsequently were resolved.