Reconstructive management of cranial base defects after tumor ablation

Successful reconstruction after cranial base tumor ablation is paramount in preventing potentially life-threatening complications. The purpose of this study nas to evaluate experiences of cranial base reconstruction and to id entify reconstructive management principles that may assist in achieving su ccessful cranial base reconstruction. AU cranial base reconstructions perfo rmed by the Depart ment of Plastic Surgery at the University of Texas M. D. Anderson Cancer Center between January of 1993 and September of 1999 were reviewed. Analyses were performed to assess the impact of location of defec t, type of reconstruction, type of dural repair, and history of preoperativ e radiation and chemotherapy on rates of complications, and patient surviva l. The 77 patients who underwent cranial base reconstruction after tumor ab lation during the study period had a mean age of 52 years (6 to 84 years). The mean follow-up period was 28.7 months (1 to 76 months). Squamous cell c arcinoma, the most common histopathologic type, was present in 24 patients (31 percent), and 35 patients (45 percent) presented with recurrent disease . Location of defects involved region I (anterior) in 31 patients (40 perce nt), region II (anterior: lateral) in 18 (23 percent), region III (lateral- posterior) in six (8 percent), and more than one region in 22 (29 percent). Reconstructive methods included free flaps in 52 patients (68 percent), te mporalis muscle flaps in 14 (15 percent), pericranial flaps in eight (10 pe rcent), and other local flaps (two galeal, one scalp) in three (4 percent). Of the 52 free flaps, 18 (35 percent) were used in region I, 14 (27 percen t) in region II, six (12 percent) in region III, and 14 (27 percent) in def ects involving more than one region. Of the 14 temporalis muscle flaps, 13 (93 percent) were used for defects involving regions I or II and one (7 per cent) was used for a defect involving region IU. Of the 11 pericranial and other local flaps, nine (82 percent) were used in region I, one (9 percent) in region II, and one 99 percent) in a combination of regions II:and m. Co mplications occurred in 21 patients (27 percent): three total flap losses ( 4 percent), three partial flap losses (4 percent), two cerebrospinal fluid leaks (3 percent), two cases of meningitis (3 percent), two abscesses (3 pe rcent), five cases of delayed wound healing (6 percent), two hematomas (3 p ercent), one wound infection (1 percent), and one cerebrovascular accident (1 percent). Overall survival was 77 percent at 2 years and 58 percent at 4 years. The type of reconstruction, location of defect, type of dural repai r, and history of preoperative radiation and chemotherapy had no significan t association with the incidence of complications. Neither the type of reco nstruction nor the location of defect showed a significant effect on patien t survival. In this experience, local flaps, such as pericranial or tempora lis muscle flaps, are good choices for reconstruction of smaller anterior o r lateral cranial base defects. For defects that require larger amounts of soft tissue, free flaps are appropriate. With proper patient selection, suc cessful cranial base reconstruction can be pet-formed with either local or free flaps with a low incidence of complications.