On “Perforator-Based Anterolateral Thigh Adipofascial or Dermal Fat Flaps for Facial Contour Augmentation (J Reconstr Microsurg 2007;23:497–503)”

We read with great interest the case series by Professor Wolff and coworkers regarding eight patients who underwent perforator-based anterolateral thigh (ALT) adipofascial or dermal fat flaps of the anterolateral thigh for facial contour augmentation.[1] We would like to congratulate the authors on their excellent clinical and written work and also to comment on some issues.

The authors reported that they used Doppler flowmetry for qualitative preoperative determination of the perforator of the ALT about at the midpoint of a line joining the anterior-superior iliac spine and the lateral border of the patella. They found the perforator to be very persistent without a variation in anatomy. Recently, various studies have been published focusing on the preoperative visualization of perforators such as for ALT, deep inferior epigastric perforator (DIEP) flaps, or free-fibula transfers using computed tomography angiography or magnetic resonance angiography.[2] [3] [4] We would be interested to know the authors' thoughts on the need for a preoperative visualization of the perforator of the ALT or whether they consider the Doppler sonography to be the standard in their clinical experience.

Free-tissue transfer is associated with reexploration rates between 5 and 25% due to circulatory compromise.[5] The time of presentation of flap compromise was a significant predictor of flap salvage outcome in a study of 1142 free-flap procedures with 113 flaps receiving reexploration in Taiwan.[6] Among these procedures, 668 ALT transfers were performed with 65 reexplorations (9.7%), with 29 arterial and 36 venous types of compromise and a salvage rate of 81.5%. Early detection of signs of vascular malperfusion is of utmost importance. Based on their thorough analysis, the authors suggested intensive flap monitoring at a special microsurgical intensive care unit even in the most experienced hands.

Especially in buried flaps often used in head and neck reconstructive microsurgical procedures, monitoring of the flap can be challenging and limited. A monitoring flap has been proposed as a simple, useful, and reliable method for assessing the vascular status of a buried free flap.[7] However, in facial recontouring a buried free-flap reconstruction is often preferred over the insertion of a monitoring island. Laser Doppler flowmetry has been reported for monitoring the buried free flaps.[8] An implantable Doppler probe, although proved to be highly sensitive, is prone to false-positive results, however.[9] Furthermore, the implantable Doppler probe might be deleterious for meticulous microsurgical anastomosis, especially in the facial area. Therefore noninvasive monitoring to assess capillary inflow and especially venous outflow might be beneficial in this regard, taking into account the previously mentioned potential for deleterious arterial and venous malperfusion problems in ALT free-flap transfer.

Interestingly, the authors of the case series were studying the effects of noninvasive monitoring of hemoglobin oxygenation of different free-flap donor sites as early as 1996.[10] [11] Noninvasive tissue oximetry for flap monitoring has been recently reported using the ODISsey Tissue Oximeter (ViOptix, Inc., Fremont, CA) among 30 patients undergoing free-flap breast reconstruction.[12] Using a combined laser Doppler and spectrophotometry system (Oxygen-to-See [O2C]; LEA Medizintechnik, Giessen, Germany), a reliable prediction of venous congestion by an increase of hemoglobin concentration and of arterial occlusion by a decrease in blood flow and tissue oxygenation is feasible.[13] Recently, we reported on the use of the O2C system for quantitative buried flap monitoring of a split latissimus dorsi free-flap transfer for orbital reconstruction after orbital evisceration and radiation therapy for retinoblastoma in childhood with a significant increase of orbital oxygenation following free-flap transfer.[14]

We would appreciate it if Wolff et al would comment regarding the monitoring tools in buried free-flap surgery for facial recontouring.

REFERENCES

• 1 Wolff K D, Kesting M, Löffelbein D, Hölzle F. Perforator-based anterolateral thigh adipofascial or dermal fat flaps for facial contour augmentation.  J Reconstr Microsurg. 2007;  23 497-503
• 2 Fukaya E, Grossman R F, Saloner D, Leon P, Nozaki M, Mathes S J. Magnetic resonance angiography for free fibula flap transfer.  J Reconstr Microsurg. 2007;  23 205-211
• 3 Hamdi M, Van Landuyt K, Van Hedent E, Duyck P. Advances in autogenous breast reconstruction: the role of preoperative perforator mapping.  Ann Plast Surg. 2007;  58 18-26
• 4 Rozen W M, Phillips T J, Asthon M W, Stella D L, Gibson R N, Taylor G I. Preoperative imaging for DIEA perforator flaps: a comparative study of computed tomographic angiography and Doppler ultrasound.  Plast Reconstr Surg. 2008;  121(1, suppl) 1-8
• 5 Schusterman M A, Miller M J, Reece G P et al.. A single center's experience with 308 free flaps for repair of head and neck cancer defects.  Plast Reconstr Surg. 1994;  93 472-477
• 6 Chen K T, Mardini S, Chuang D CC et al.. Timing of presentation of the first signs of vascular compromise dictates the salvage outcome of free flap transfers.  Plast Reconstr Surg. 2007;  120 187-195
• 7 Cho B C, Shin D P, Byun J S, Park J W, Baik B S. Monitoring flap for buried free tissue transfer: its importance and reliability.  Plast Reconstr Surg. 2002;  110 1249-1258
• 8 Yuen J C. Techniques of external monitoring in buried free flaps.  Ann Plast Surg. 2005;  55 460-465
• 9 Rosenberg J J, Fornage B F, Chevray P M. Monitoring buried free flaps: limitations of the implantable Doppler and use of color Duplex sonography as a confirmatory test.  Plast Reconstr Surg. 2006;  118 109-113
• 10 Wolff K D, Marks C, Uekermann B, Specht M, Frank K H. Monitoring of flaps by measurement of intracapillary haemoglobin oxygenation with EMPHO II: experimental and clinical study.  Br J Oral Maxillofac Surg. 1996;  34 524-529
• 11 Wolff K D, Kolberg A, Mansmann U. Cutaneous hemoglobin oxygenation of different free flap donor sites.  Plast Reconstr Surg. 1998;  102 1537-1543
• 12 Keller A. Non-invasive tissue oximetry for flap monitoring: an initial study.  J Reconstr Microsurg. 2007;  23 189-198
• 13 Hölzle F, Loeffelbein D J, Nolte D, Wolff K D. Free flap monitoring using simultaneous non-invasive laser Doppler flowmetry and tissue spectrophotometry.  J Craniomaxillofac Surg. 2006;  34 25-33
• 14 Knobloch K, Gohritz A, Vogt P M. Noninvasive monitoring of microcirculatory perfusion and oxygenation in subcutaneous microsurgical flaps.  J Reconstr Microsurg. 2008;  24 69