Innovative CAD/CAM Guide for Mandibular Reconstruction with Metallic Condylar Head and Free Fibular Flap.

In reconstructions of mandibles and condyles, free fibular flaps and metallic condylar heads (CH) are often used after resection. However, in conventional reconstructions, it is difficult to fix the metallic CH on the same preoperative position because the position is determined visually. Therefore, we have made an original computer-aided design and manufacture (CAD/CAM) guide for mandibular condyle reconstruction, combining a metallic CH with a free fibular flap. A 71-year-old woman with gingival carcinoma underwent hemimandibulectomy. We reconstructed the mandible and condyle with a metallic CH and a free fibular flap. We placed a mark on the CAD/CAM guide showing the correct position for fixing the CH to the fibular blocks. We also designed a surface for attaching to the healthy edge of the mandible. The fibular blocks and metallic CH were fixed as 1 unit before separating the flap from the leg and replacing the diseased tissue. Reconstruction was completed by fixing the attachment surface to the healthy side of the mandible. The guide marks solved the difficulty of conventional reconstruction; during surgery, we fixed the metallic CH to the same position as the original bone using these marks. The postoperative deviation of the condyle from the virtual plan was 4.3 mm, whereas the reported deviation of such prostheses was 3.8 mm (range 1.3-6.7); so our guide was acceptably accurate. Furthermore, it appears that the CAD/CAM guide is more useful for reconstruction after hemimandibulectomy including the condyle than after segmental resection without including condyle.

Does an In-House Computer-Aided Design/Computer-Aided Manufacturing Approach Contribute to Accuracy and Time Shortening in Mandibular Reconstruction?

Mandibular reconstruction using computer-aided design and computer-assisted manufacturing (CAD/CAM) techniques has received recent attention. This technique has theoretical advantages, although this approach can be commercially used in the limited area of the world.The aim is to describe our experience using in-house CAD/CAM guides and the situations in which CAD/CAM may present benefit in the region where commercial guides are unavailable.The authors developed our In-house CAD/CAM approach for mandibular reconstructions with a free fibular flap. Patients were divided into 2 group; CAD/CAM and conventional groups. In the CAD/CAM group, reconstructions were planned virtually using CAD/CAM; these CAD/CAM guides were used in the surgery. In the conventional group, free-hand cutting and fitting of the fibular segments were performed as reconstructions. Later, the bone computed tomographic image was compared with the plan. The averaged deviations and the percentages of the points within 1 mm, 2 mm, and 3 mm deviations were recorded. Total and ischemic time were also recorded.Reconstruction points within 1 mm deviation were 59% of CAD/CAM group (n = 9) and 42% of conventional group (n = 10, P = 0.04), within 2 mm 82% and 69% (P = 0.03). Total time were 1012 and 911 minutes, while flap ischemic time were 147 and 175 minutes (P = 0.03), respectively.In-house CAD/CAM mandibular reconstruction also supported accuracy and shorter flap ischemic time. For a detailed accurate reconstruction, CAD/CAM showed superiority than conventional method. Use of the In-house CAD/CAM guides might be an option where commercial guides are not available.

Two Cases of the Vascular Territory of a Single-pedicled Deep Inferior Epigastric Perforator Flap with a Vertical Midline Abdominal Scar.

: The deep inferior epigastric perforator (DIEP) flap is becoming the gold standard for breast reconstruction using autologous tissue. If there are scars in the abdomen from previous surgery, it is necessary to judge the indication for using this flap carefully. Particularly in cases with vertical midline scars, the blood flow supply to the zone II can be compromised. Even when patients have a median abdominal scar, it has been reported that the blood flow can extend beyond the scar and reach several centimeters to about half of zone II. We performed breast reconstruction using DIEP flaps for 2 patients with vertical midline scars in the lower abdomen. Indocyanine green angiography was conducted intraoperatively to confirm the vascular territory with a single pedicle before cutting off the flap. One patient showed fluorescence contrast on the contralateral side across the midline scar. However, the fluorescence contrast was absent across the midline scar in the other patient. Based on this result, we investigated the possible vascular territory of a single pedicled DIEP flap in patients with vertical midline abdominal scars. We suggest that successful blood supply to zone II of a single-pedicled DIEP flap in a patient with a vertical midline abdominal scar is related to the location of the perforator and the property of the tissue in the midline near the perforator. However, because it is difficult to predict the vascular territory of a single pedicle before surgery, intraoperative evaluation using such techniques such as indocyanine green fluorescence imaging is important.

Extended latissimus dorsi chimeric thoracoplasty with a vascular supercharge for Aspergillus empyema.

The latissimus dorsi and serratus anterior muscles are available for reconstruction coverage of thoracic defects. We performed extended latissimus dorsi-serratus anterior chimeric thoraco-myoplasty with a vascular supercharge to maintain sufficient blood supply to the flaps because of a deficiency in the distal blood flow to the flap revealed by an intravenous injection of indocyanine green and simultaneous endobronchial embolization for refractory Aspergillus empyema.

Designing CAD/CAM Surgical Guides for Maxillary Reconstruction Using an In-house Approach.

Computer-aided design/computer-assisted manufacturing (CAD/CAM) is now being evaluated as a preparative technique for maxillofacial surgery. Because this technique is expensive and available in only limited areas of the world, we developed a novel CAD/CAM surgical guide using an in-house approach. By using the CAD software, the maxillary resection area and cutting planes and the fibular cutting planes and angles are determined. Once the resection area is decided, the necessary faces are extracted using a Boolean modifier. These superficial faces are united to fit the surface of the bones and thickened to stabilize the solids. Not only the cutting guides for the fibula and maxilla but also the location arrangement of the transferred bone segments is defined by thickening the superficial faces. The CAD design is recorded as .stl files and three-dimensionally (3-D) printed as actual surgical guides. To check the accuracy of the guides, model surgery using 3-D-printed facial and fibular models is performed. These methods may be used to assist surgeons where commercial guides are not available.

Using an In-House Approach to Computer-Assisted Design and Computer-Aided Manufacturing Reconstruction of the Maxilla.

PURPOSE: Computer-assisted design (CAD) and computer-aided manufacturing (CAM) techniques are in widespread use for maxillofacial reconstruction. However, CAD/CAM surgical guides are commercially available only in limited areas. To use this technology in areas where these commercial guides are not available, the authors developed a CAD/CAM technique in which all processes are performed by the surgeon (in-house approach). The authors describe their experience and the characteristics of their in-house CAD/CAM reconstruction of the maxilla. PATIENTS AND METHODS: This was a retrospective study of maxillary reconstruction with a free osteocutaneous flap. Free CAD software was used for virtual surgery and to design the cutting guides (maxilla and fibula), which were printed by a 3-dimensional printer. After the model surgery and pre-bending of the titanium plates, the actual reconstructions were performed. The authors compared the clinical information, preoperative plan, and postoperative reconstruction data. The reconstruction was judged as accurate if more than 80% of the reconstructed points were within a deviation of 2 mm. RESULTS: Although on-site adjustment was necessary in particular cases, all 4 reconstructions were judged as accurate. In total, 3 days were needed before the surgery for planning, printing, and pre-bending of plates. The average ischemic time was 134 minutes (flap suturing and bone fixation, 70 minutes; vascular anastomoses, 64 minutes). The mean deviation after reconstruction was 0.44 mm (standard deviation, 0.97). The deviations were 67.8% for 1 mm, 93.8% for 2 mm, and 98.6% for 3 mm. The disadvantages of the regular use of CAD/CAM reconstruction are the intraoperative changes in defect size and local tissue scarring. CONCLUSION: Good accuracy was obtained for CAD/CAM-guided reconstructions based on an in-house approach. The theoretical advantage of computer simulation contributes to the accuracy. An in-house approach could be an option for maxillary reconstruction.

Secondary Maxillary and Orbital Floor Reconstruction With a Free Scapular Flap Using Cutting and Fixation Guides Created by Computer-Aided Design/Computer-Aided Manufacturing.

Computer-aided design/computer-aided manufacturing (CAD/CAM) guides are now widely used in maxillofacial reconstruction. However, there are few reports of CAD/CAM guides being used for scapular flaps. The authors performed the secondary maxillary and orbital floor reconstruction using a free latissimus dorsi muscle, cutaneous tissue, and scapular flap designed using CAD/CAM techniques in a 72-year-old man who had undergone partial maxillectomy four years previously. The patient had diplopia, the vertical dystopia of eye position, and a large oral-nasal-cutaneous fistula. After the operation, the authors confirmed that the deviation between the postoperative and preoperative planning three-dimensional images was less than 2 mm. Because scapular guides require 3 cutting surfaces, the shape of the scapular guide is more complex than that of a conventional fibular guide. In orbital floor reconstruction, the use of a CAM technique such as that used to manufacture the authors' fixation guide is as necessary for accurate, safe, and easy reconstruction as is preoperative CAD planning. The production of a fixation guide as well as a cutting guide is particularly useful because it is difficult to determine the angle for reconstructing the orbital floor by freehand techniques. In this case, the orbital floor was reconstructed based on a mirror image of the healthy side to avoid overcompression of the orbital tissue. Although the patient's vertical dystopia of eye position was improved, diplopia was not improved because, for greater safety, the authors did not plan overcorrection of the orbital volume.