From the Hansjörg Wyss Department of Plastic Surgery, New York University Langone Medical Center; the Department of Surgery, Head and Neck Service, and the Plastic and Reconstructive Surgery Service, Memorial Sloan Kettering Cancer Center; the Division of Plastic and Reconstructive Surgery, Department of Surgery, Montefiore Medical Center/Albert Einstein College of Medicine; and 3D Systems.
Plast Reconstr Surg. 2019 Apr;143(4):1197-1206. doi: 10.1097/PRS.0000000000005452.
The absence of a tumor specimen from which to obtain measurements at the time of delayed maxillomandibular reconstruction introduces degrees of uncertainty, creating the need for substantial intraoperative guesswork by the surgeon. Using the virtual surgical planning environment, the size and shape of missing bony elements is determined, effectively "recreating the defect" in advance of the surgery. Three virtual surgical planning techniques assist the reconstructive surgeon: patient-specific modeling, mirroring the normal contralateral side, and scaled normative data. To facilitate delayed reconstruction a hierarchical algorithm using virtual surgical planning techniques was developed.
Delayed maxillomandibular virtual surgical planning reconstructions were identified from 2009 to 2016. Demographics, modeling techniques, and surgical characteristics were analyzed.
Sixteen reconstructions were performed for osteoradionecrosis with displacement (50.0 percent) or oncologic defects (37.5 percent). Most patients had prior surgery (81.3 percent) and preoperative radiation therapy (81.3 percent); four had failed prior reconstructions. The following delayed virtual surgical planning techniques were used: patient-specific modeling based on previous imaging (43.8 percent), mirroring normal contralateral anatomy (37.5 percent), and scaled normative data (18.8 percent). Normative and mirrored reconstructions were designed to restore normal anatomy; however, most patient-specific virtual surgical planning designs (71.4 percent) required nonanatomical reconstructions to accommodate soft-tissue limitations and to avoid the need for a second flap. One partial flap loss required a second free flap, and one total flap failure occurred. Hardware exposure was the most common minor complication, followed by infection, dehiscence, and sinus tract formation.
Virtual surgical planning has inherent advantages in delayed reconstruction when compared to traditional flap shaping techniques. An algorithmic approach based on available imaging and remaining native anatomy enables accurate reconstructive planning followed by flap transfer without the need for intraoperative guesswork.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.
在延迟的上颌骨和下颌骨重建时，如果没有肿瘤标本来获取测量值，就会存在一定程度的不确定性，这就需要外科医生在手术过程中进行大量的猜测。使用虚拟手术规划环境，可以确定缺失的骨元素的大小和形状，从而在手术前有效地“重建缺陷”。三种虚拟手术规划技术可以帮助重建外科医生：患者特异性建模、镜像正常对侧以及比例正常的标准数据。为了促进延迟重建，开发了一种使用虚拟手术规划技术的分层算法。
从 2009 年到 2016 年，我们确定了 16 例因放射性骨坏死伴移位（50.0%）或肿瘤性缺损（37.5%）而进行的延迟上颌骨和下颌骨虚拟手术规划重建。大多数患者都有先前的手术（81.3%）和术前放疗（81.3%），其中 4 例患者先前的重建失败。以下是使用的延迟虚拟手术规划技术：基于以前的影像学资料的患者特异性建模（43.8%）、镜像正常的对侧解剖结构（37.5%）和比例正常的标准数据（18.8%）。标准和镜像重建旨在恢复正常解剖结构；然而，大多数患者特异性虚拟手术规划设计（71.4%）需要非解剖重建来适应软组织限制，并避免需要第二个皮瓣。有一例部分皮瓣丧失需要第二个游离皮瓣，有一例完全皮瓣失败。硬件暴露是最常见的小并发症，其次是感染、裂开和窦道形成。
与传统的皮瓣成形技术相比，虚拟手术规划在延迟重建中具有固有优势。基于现有影像学资料和剩余的天然解剖结构的算法方法可以实现准确的重建规划，然后进行皮瓣转移，而无需在手术过程中进行猜测。
临床问题/证据水平：治疗，IV。
