Two New Techniques for Correcting Venous Congestion in the Free DIEP Flap for Breast Reconstruction: An Analysis of Venous Augmentation in 581 DIEP Flaps

Abstract

Sir: The deep inferior epigastric perforator (DIEP) flap has become the standard method of autologous breast reconstruction following mastectomy. Decision making is an essential component of perforator selection with regard to fat necrosis, impending venous congestion, and ultimately flap survival. Venous congestion is often caused by variable venous anatomy across the midline or insufficient venous caliber. The contralateral or ipsilateral superficial inferior epigastric vein can be used to provide the required drainage of the flap. It is important to understand which of the venous systems, deep or superficial, is dominant before ligation of the pedicle. We present two new techniques for enabling augmentation of the DIEP venous drainage system should it be required and examine its need in 581 consecutive DIEP flaps. The techniques described have been used before the insetting of the DIEP flap to avoid venous problems postoperatively. Bilaterally, the superficial inferior epigastric veins are dissected out and clamped regardless of vessel caliber. The DIEP flap is then harvested based on a perforator that was clinically judged to be of adequate caliber. We have found no “dynamic quantitative” benefit in the use of preoperative computed tomographic angiography. Computed tomographic techniques help in identifying the perforator but give no indication of whether the blood flowing through the perforator will be adequate to sustain the flap. Before ligation of the perforator, the clamped superficial inferior epigastric veins on both sides are observed and their filling or lack of it noted along with the capillary refill of the flap. Venous engorgement implies that the venae comitantes are not dominant or the caliber of the venous perforator is insufficient. Therefore, an additional anastomosis using the superficial inferior epigastric vein is required. Routinely, the deep inferior epigastric artery and one of the venae comitantes (deep inferior epigastric vein) is anastomosed to the internal mammary artery and internal mammary vein, respectively. If the superficial inferior epigastric veins are seen to be engorged in the same manner as before, one of two techniques can be used. Venous congestion can become a significant problem in the perioperative period and if unsolved can lead to flap failure. DIEP flap failure has a tendency to be venous in origin. Many methods of venous augmentation have been described that are potentially hazardous and complicated. Niranjan et al. describe using the opposite deep inferior epigastric vein to anastomose to the cephalic vein using an interpositional vein graft.1 Cohn and Walton used the deep inferior epigastric vein and superficial inferior epigastric vein to anastomose to the internal mammary and the thoracodorsal veins.2 Tutor et al. described the use of the intercostal branch of the internal mammary vein to anastomose to the deep inferior epigastric vein.3 Barnett et al. describe a technique whereby the cephalic vein is divided distally and brought into the infraclavicular area before anastomosing it to the superficial inferior epigastric vein.4 All these methods can successfully augment venous congestion. However, it requires the separate dissection of a recipient vein and therefore flap inset and breast shaping may be a problem. Cephalic vein harvest is not without donor-site morbidity, with a potentially avoidable scar. All these factors contribute to unnecessary operative time and morbidity. Liu et al. describe salvage of a congested DIEP flap by use of the superficial inferior epigastric vein for venous augmentation by means of a reverse flow end-to-end anastomosis onto the second deep inferior epigastric vein.5 This reverse flow technique using the end of the deep inferior epigastric vein to anastomose to the superficial inferior epigastric vein assumes there are no valves or that the valves will be rendered incompetent. This technique may not always be successful. Our first technique (Fig. 1) is simple and safe using anterograde flow. It takes less than 30 minutes. An advantage is that it allows an extra 5 to 6 cm of venous pedicle length: anastomosing into the venae comitantes proximally may be the only option, as the pedicle length may be too short for the internal mammary vein recipient vessel. In 57 DIEP flaps (i.e., 9.8 percent) where this technique was used, there were no flap losses. This is a safe venous augmentation method and is the only technique that provides extra pedicle length without further scarring.Fig. 1.: The standard anastomosis to the internal mammary artery (IMA) and internal mammary vein (IMV) is carried out. During flap elevation, the pedicle is transected sufficiently caudally that it is distal to a venous interconnection. The remaining vena comitans that has not been used for the internal mammary anastomosis is dissected carefully from the adjacent deep inferior epigastric artery under the operating microscope. This dissection is carried out proximal to one of the distal venous interconnections and approximately 4 to 5 cm of vena comitans is mobilized for anastomosis. This extra length enables easier flap inset. The proximal end is ligated and the superficial inferior epigastric vein is anastomosed end-to-end to the vena comitans using 9-0 Ethilon sutures (Ethicon, Inc., Somerville, N.J.). This enables the flap to drain the superficial system in addition to the deep system through the venous interconnection.Our second technique (Fig. 2) requires the use of perioperative planning during flap elevation. Leaving a large venous branch of 2 cm length, instead of ligating close to the main pedicle, is another option in the venously congested flap. This was used in 11 DIEP flaps (i.e., 1.9 percent), and no flap losses were recorded.Fig. 2.: The standard anastomosis to the internal mammary artery (IMA) and internal mammary vein (IMV) is carried out. During flap elevation, many side branches are seen that require ligation en route to the origin of the DIEP vessels in the groin. One of the larger side branches (artery and vein) is ligated with approximately 2 cm of length remaining to the adjoining main pedicle. This is carried out routinely in case it is needed for later use. The pedicle is inspected and one must ensure that the side branch lies proximal to a venous interconnection. The superficial inferior epigastric vein is anastomosed end-to-end to the venous side branch using 9-0 Ethilon sutures. This enables the flap to drain the superficial system in addition to the deep into the internal mammary vein through the venous interconnections. There are two disadvantages: first, these side branches are usually more cephalic in the pedicle; and second, additional length cannot be gained by dissecting the vein more cephalically.Overall, our DIEP failure rate in 581 cases was five flaps (i.e., 0.86 percent). The technique chosen was determined by the configuration of the flap inset to achieve a desirable aesthetic result. Our two techniques are effective, rely on flap vessels, and did not add any further morbidity. Nilesh M. Sojitra, B.Sc., M.Sc., M.B.Ch.B. Department of Plastic and Reconstructive Surgery Royal Free Hospital London, United Kingdom Marc Vandevoort, M.D., F.C.C.P. Department of Plastic Surgery H. Hart Ziekenhuis, and Department of Plastic Surgery Universitair Ziekenhuis Gasthuisberg Leuven, Belgium Shadi Ghali, M.B.B.S., M.R.C.S. Department of Plastic and Reconstructive Surgery Royal Free Hospital London, United Kingdom Gerd Fabre, M.D., F.C.C.P. Department of Plastic Surgery H. Hart Ziekenhuis, and Department of Plastic Surgery Universitair Ziekenhuis Gasthuisberg Leuven, Belgium