الفهرس 
ACKNOWLEDGMENTOnly 14 pages are availabe for public view
 |  | from | 203 |  |  |
| | | from | 203 | | |
Abstract
In this study, we transferred 11 DIEP free flaps for reconstruction of challenging soft tissue defects in the oro-facial region due to various causes. All patients were admitted to the Maxillofacial and Plastic Surgery Unit, Faculty of Dentistry, Alexandria University, Egypt, in the period between June 2012 and October 2015.
All our patients had a thorough clinical examination supplemented by both laboratory and radiological investigations. Preoperative mapping of the perforators using CT angiography was done to all cases. This was of ultimate importance to identify the branching pattern of DIEA as well as perforator course. The data gained by the CT angiography played a significant role in preoperative decision of the side of the donor hemiabdomen and the ideal perforator used to perfuse the flap.
Preoperative anaesthetic evaluation, photography and flap design were performed in the preoperative assessment visit at the night before operation, as routine in this series, all patients were admitted to the intensive care unit (ICU) in the first 5-7 days postoperatively. The patient was then transferred the maxillofacial ward after stability of the general condition, assurance of the flap viability, and return of critical laboratory investigations to their normal levels.
After patient discharge, follow up regarding the efficacy of the chosen reconstructive option, donor site morbidity, and evaluation of function and aesthetics of both the reconstructed oro-facial area and the donor abdomen.
We found that the majority of our cases were post ablative affecting mainly males of the middle age group. The soft tissue defects were both intra and extra oral. Nearly all of our patients were primarily reconstructed. The mean size of the flap was 10×7 cm, with a vascular pedicle length ranging from 10 to 18.5 cm. The mean time of flap harvesting was 111 minutes.
Regarding the DIEA perforators, 84% were musculocutaneous (48 % had shot intramuscular course and 36 % had long intramuscular course) and 16 % were septocutaneous or pararectal. We found also that there is an intimate relation of the motor nerve branch to the rectus muscle and the vessel during dissection of lateral row perforators. Careful dissection was performed to avoid nerve injury to decrease the donor site morbidity.
Most of major perforators (96.8%) detected by the CTA were located within 6 cm radius around the umbilicus. This finding was consistent with the intraoperative finding.
There was an instance of significant intraoperative bleeding in one patient that was controlled with difficulty by the neurosurgical team. The recipient site was skin grafted and packed and the harvested flap was left in place and sutured back to the abdominal skin. On the 5th postoperative day the patient was sent to the operating theater and the flap was lost due to thrombosis of the pedicle vein as the patient had DIC and received vasopressors. We harvested another flap from the other side of the abdomen and reconstruction was successful. Perforator injury and intraoperative flap failure occurred in one of our patients and another flap was harvested from the other side.
All donor site were primarily closed whether we used the abdominoplasty or vertical design. Our flap survival success rate was 82 %. IJV thrombosis occurred in the first postoperative day in one patient. The second flap was lost due to thrombosis at the venous anastomosis at 8th postoperative day and the defect was reconstructed with pectoralis major flap.
Hematoma was reported in one patient in the first postoperative day. Patient was transferred to the operating theatre and rapid evacuation of the hematoma and hemostasis were performed. Another patients developed seroma deep to the abdominal wound in the 9th postoperative day. Treatment was successful after repeated daily aspiration.
Wound dehiscence occurred in 4 patients that was managed by secondary sutures in one patient and by conservative measures and frequent dressing in the other patients. Being a bulky flap, heaviness and tension on the suture line are most probably the cause of wound dehiscence.
Hypertrophic scar was reported at the donor site in one patient.The flap was found bulky in two patients. Of these, one patient had primary flap thinning intraoperatively and the other patient had secondary debulking. No morbidities at the donor site were noted in any of our patients and abdominal wall strength was not affected due to preservation of rectus muscle and its motor nerve supply. One patient died 3 months postoperatively due to recurrence of the osteosarcoma.
from this study we can conclude the DIEP flap has many advantages that can be summarised as following:
1- Harvesting of the flap is safe because there are usually many perforators arising from the DIEA with extremely rare anatomical variation. Nevertheless, flap elevation is not an easy job for conventional microsurgeon as it requires experience and more skills which can be acquired with time.
2- The DIEP flap has a long vascular pedicle which can reach up to 18.5 cm especially when a distal perforator is used and when the DIEA is dissected to its origin. Therefore, microvascular anastomoses can be performed far away from the defect area, even on the contralateral side as in irradiated neck.
3- The diameter of the proximal end of the vascular pedicle is approximately 3 mm or more. This diameter is as wide as the radial vessels, making the microvascular anastomosis easier.
4- The skin territory of the DIEP is very wide and large, and a large flap measuring 21x12 cm in diameter can be harvested based only on one perforator.
5- The donor site is away from the head and neck, this allows simultaneous two-team work at which one team elevate the flap and the second one excise the tumour and prepare the recipient site with shorter operative time.
6- The donor site is closed primarily with minimal morbidity, both in terms of function and cosmesis.
7- The shape of the DIEP is not limited as it can be designed as required as a free style flap.
8- The other hemiabdomen can be used as a lifeboat in case of flap failure especially when vertical design is used.
9- CTA is a useful tool for directing decisions regarding donor side, and in addition to demonstrating the entire perforators’ vascular anatomy of the region. We recommend it particularly for surgeons with limited experience with this flap as it avoids potential pitfalls at the time flap harvest.
On the other hand, the DIEP has certain disadvantages which include the following:
1- DIEP flap is bulky especially in obese patients. This can be beneficial when tissue bulk is needed and to obliterate dead spaces. However, flap thinning can be performed either primarily or secondary.
2- DIEP flap has a poor colour matching with the facial skin.
Finally, we conclude that the DIEP flap has unlimited range of versatility and efficacy in the reconstructive microsurgery of the head and neck. Due to the combined advantages of minimal donor site morbidity, and the satisfying results, the DIEP flap can be considered a universal donor site which is ideally suited for soft tissue reconstruction in cranio-maxillofacial surgery. A wide range of future clinical applications of this flap is expected. It is highly important for maxillofacial surgeons to experience more clinical cases.