We read with great interest the article entitled “Optimizing Perforator Selection: A Multivariable Analysis of Predictors for Fat Necrosis and Abdominal Morbidity in DIEP Flap Breast Reconstruction.”1 We congratulate on the authors on finding the predicting factors for fat necrosis and abdominal morbidity in the patient undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction.
Adequate blood flow is one of the key elements of successful free flap reconstruction.2 According to the authors’ assumption, the pressure differential was between a theoretical 120 and 80 mmHg to simulate systolic and diastolic blood pressures, viscosity was 40 mP for blood, and the length was 1 mm. As a result, the authors were able to calculate the flow rate from vessel calibers based on the Poiseuille law. However, we wonder if it is still applicable in terms of hypertension patients. For patients with hypertension, especially poorly controlled hypertension, the pressure differential is certainly way out of the assumed range. Therefore, we think it might not be a proper way to calculate the flow rate. The study by Feng et al.2 disclosed that color Doppler ultrasound offers hemodynamic information about perforator quality, such as velocity, caliber, resistance index, and detailed anatomical information. We would love to know if it would be better to adopt the duplex ultrasound to directly measure blood flow velocity and take independent blood pressure measurements, as some other studies2–4 have done.
In terms of perforator selection, the authors classified the row of perforators as medial, lateral, or both. However, it is a rough classification, and does not take into consideration the superior versus inferior row and the central versus peripheral row. It would have been of greater help if the authors had made a more detailed comparison for other practitioners when designing the flap based on the row of the perforator.
Apparently, in their study the authors evaluated only fat necrosis in terms of recipient-site complications. We would ask the authors whether they have further studied the relationship of the potential factors with some other complications, such as flap loss, venous congestion, and hematoma/seroma.
The authors have no financial interest to declare in relation to the content of this communication. There was no funding for this work.
Yunzhu Li, M.D.Xiao Long, M.D.Division of Plastic and Reconstructive SurgeryPeking Union Medical College HospitalBeijing, People’s Republic of China
1. Hembd A, Teotia SS, Zhu H, Haddock NT. Optimizing perforator selection: A multivariable analysis of predictors for fat necrosis and abdominal morbidity in DIEP flap breast reconstruction. Plast Reconstr Surg. 2018;142:583–592.
2. Feng S, Min P, Grassetti L, et al. A prospective head-to-head comparison of color Doppler ultrasound and computed tomographic angiography in the preoperative planning of lower extremity perforator flaps. Plast Reconstr Surg. 2016;137:335–347.
3. Jin SJ, Suh HP, Lee J, Hwang JH, Hong JPJ, Kim YK. Lipo-prostaglandin E1 increases immediate arterial maximal flow velocity of free flap in patients undergoing reconstructive surgery. Acta Anaesthesiol Scand. 2019;63:40–45.
4. Innocenti M, Santini M, Dreassi E, et al. Effects of cutaneous negative pressure application on perforator artery flow in healthy volunteers: A preliminary study. J Reconstr Microsurg. 2019;35:189–193. E-published ahead of print August 15, 2018.