Punctate Midline Myelotomy: A Historical Overview and Case Series with Detailed Efficacy and Side Effect Profiles.

ABSTRACT

OBJECTIVE: To review our experience with punctate midline myelotomy (PMM) for malignant and benign visceral pain with an emphasis on detailed side-effect profiles and efficacy. METHODS: Thirteen adults (5 men) underwent microsurgical transverse-crush PMM. RESULTS: Median follow-up for the benign pain group (n = 6) was 17.5 months (10-72) and for the malignant group (n = 7) was 8 months (0.5-31). Five of seven patients in the malignant pain group obtained excellent, lasting relief. Two had initial relief followed by worsening pain with disease progression. In the benign pain group, two patients with endodermal-origin pain (gastrointestinal tract, bladder) had complete, long-lasting relief. Three patients with mesodermal-origin pain (ureter) had excellent relief for 2-3 months, followed by recurrence in two and partial (40%) recurrence in the third. One man with pre-existing cervical myelopathy underwent PMM for benign testicular-region pain from which he had long-term relief but only transient relief of coexisting low-back and leg pain. There were no motor deficits in either group, and all patients remained ambulatory and continent. The most common side effect was transient numbness of the medial leg and foot. Two patients (both with pre-existing spinal pathology) reported persistent moderate reduction of bowel, bladder, and sexual sensation. CONCLUSIONS: PMM offers substantial pain relief for carefully selected patients with intractable visceral pain. Relief from primarily endoderm-derived structures was most complete and long-lasting. Relief from mesoderm-derived structures was typically transient or incomplete. There was essentially no relief from pain of ectoderm-derived structures. Detailed preoperative counseling is important, especially for those with pre-existing neurologic deficits.