Original article

J Chin Med Assoc

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Transillumination method for intraoperative mapping subfascial plexus of free-style radial forearm flapJen-Wu Huanga,b,*, Yi-Ying Linb,c

aDepartment of Surgery, National Yang-Ming University Hospital, Yi-Lan, Taiwan, ROC; bInstitute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan, ROC; cDepartment of Pediatrics, Heping Fuyou Branch, Taipei City Hospital, Taipei, Taiwan, ROC

1. INTRODUCTIONHead and neck reconstruction is one of the most challenging procedures for plastic surgeons. The radial forearm flap is one of the seven standard procedures in head and neck reconstruc-tion because it can provide thin and pliable soft tissue to fit the defect. Additionally, the forearm flap can be folded in bipad-dled fashion, in which the intervening skin was de-epithelialized or bisected down to fascia for facilitating folding the flap.1,2 Bhathena et al stated that the bipaddled flap could be used as two or more separate paddles to provide skin cover and mucosa lining simultaneously.1 Although the cutaneous vascular territo-ries of the forearm has been documented,3 anatomical variation of perforator characteristics still exists.4 Without well recogniz-ing the vascular territories of the perforator, the pedicle may be damaged and the survival of the flap diminished.

In this study, we designed an intraoperative mapping technique using the transillumination method. The transillumination method has a long history and has been widely applied in many aspects.5–7 In this method, the sample is illuminated by transmission of light through the sample. For example, by holding a light behind the scrotum, pediatricians can determine whether a mass is cystic (light shines through) or solid (light blocked by the mass). If there is a hydrocele, transillumination will reveal clear fluid surround-ing the testicle.6 The use of transillumination for vascular access is an even older concept, which was first described in the 1970s.8 Additionally, the transillumination method has been applied in the identification of mesenteric vascular network. By placing a light source behind the mesentery, transillumination provides a pro-jected surgical field in which surgeons can more clearly see the vas-culature.7 With the same motivation, we used the transillumination method for intraoperative vascular mapping of subfascial plexus of the perforator in radial forearm flap. This study described this technique and compared the perioperative outcomes and compli-cations of this method with those of the standard folded radial forearm flap in head and neck reconstruction.

2. METHODS

2.1. SubjectsBetween January 2011 and December 2017, we applied the transillumination method on 12 patients who underwent head and neck reconstruction with forearm flaps immediately after

*Address correspondence: Dr. Jen-Wu Huang, Department of Surgery, National Yang-Ming University Hospital, 169, Siaoshe Road, Yilan County 260, Taiwan, ROC. E-mail address: jenwuhuang@gmail.com (J.-W. Huang).

Conflicts of interest: The authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article.

Journal of Chinese Medical Association. (2019) 82: 558-561.

Received February 26, 2019; accepted March 11, 2019.

doi: 10.1097/JCMA.0000000000000117.Copyright © 2019, the Chinese Medical Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

AbstractBackground: Without well recognizing the vascular territories of the perforator, it might damage the pedicle and diminish the survival of the flap. This study described a transillumination method for intraoperative mapping of subfascial plexus of the perforator in radial forearm flap and also compared the perioperative outcomes and complications of the method with the standard folded, bipaddled forearm flap in head and neck reconstruction.Methods: Between January 2011 and December 2017, we applied the transillumination method in 12 patients who underwent head and neck reconstruction with forearm flaps immediately after surgical resection of oral cancer (case group). For comparison, we identified 12 age- and gender-matched patients who received head and neck reconstruction with folded, bipaddled radial forearm flaps (control group). Demographic factors, diagnosis, flap size, perioperative data, and postoperative complications were compared between the two groups.Results: There was no significant difference in harvesting time, operative time, or blood loss between the case and control groups. No patient experienced donor-site complication. There was no significant difference in recipient-site complication between the case and control groups.Conclusion: The transillumination method can allow plastic surgeons to easily identify the perforator vascular plexus of the radial forearm flap, which facilitates intraoperative flap design in head and neck reconstruction without increasing harvesting time and risk of postoperative complications.

Keywords: Head and neck reconstruction; Perforator flap; Radial forearm flap; Transillumination

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surgical resection of oral cancer (case group). For compari-son, we identified 12 age- and gender-matched patients who received head and neck reconstruction using standard folded, bipaddled radial forearm flap (control group). We compared baseline demographic factors, diagnosis, flap size, periopera-tive data (ie, harvesting time, operative time, and blood loss), and postoperative complications between the two groups. Postoperatively, all patients were requested to receive out-patient follow-up for at least 3 months. This retrospective case-control study was ethically approved by the Institutional Review Board in National Yang-Ming University Hospital.

2.2. Surgical techniqueAfter complete surgical removal of oral cavity cancer, head and neck reconstruction was performed using a forearm

flap (Fig.  1A). The forearm flap was planned and the loca-tion of perforator was confirmed by a handheld acoustic Doppler. The forearm flap was harvested with preservation of the radial artery pedicle (Fig. 1B). In the application of the transillumination method, the operator elevated the fore-arm flap and the assistant placed a light source behind the flap. Details of the method are similar to those previously described by Liu 2010.7 The transillumination effect allows clear identification of the subfascial plexus, the territories of the perforator branches, and the watershed area, which was the suitable location to partially divide the flap (Fig. 1C). The forearm flap can be then further designed and shaped with only one perforator (Fig. 1D). Finally, the forearm flap was inset into the defect for subsequent reconstruction (Fig. 1E).

Fig. 1 A, A mouth floor and partial tongue defect after surgical resection of tongue cancer. B, The forearm fasciocutaneous flap was harvested with preservation of the radial artery pedicle. C, Using intraoperative transillumination method, the vascular territories of the perforator branches and the subfascial plexus were identified. The arrow indicated the watershed area, which was the suitable place to partially divide the flap. P: perforator. D, The 5 × 7 cm forearm flap was further designed and shaped into two 7 × 3cm and 7 × 2cm flaps. E, The forearm flap was inset into the defect and sutured to the remaining mucosa.

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Huang et al J Chin Med Assoc

2.3. Statistical analysisThe continuous variables were presented as median (interquartile range) and the categorical variables were presented as count (per-centage). To compare the two groups, Mann-Whitney U test and Fisher Exact test were used for continuous variables and categori-cal variables, respectively. A two-tailed p < 0.05 indicated statistical significance. All analyses were performed using IBM SPSS Statistics for Windows, Version 19.0 (IBM Corporation, Armonk, NY, USA).

3. RESULTS

Table presents the comparison of the case and control groups. The distribution of diagnoses differed significantly between the two groups. Patients in the case group mainly had cancer in the tongue and mouth floor, whereas most of the patients in the control group had buccal, gingival, and palate cancers. There was no significant difference in harvesting time, operative time, or blood loss between the case and control groups. In this study, no patient experienced donor-site complication. There was no significant difference of recipient-site complications between the case and control groups. Both groups had median periods of follow-up of more than 6 months (Table).

4. DISCUSSION

This study described an intraoperative transillumination method for mapping of subfascial plexus of forearm flap and compared the perioperative outcomes and complications of the method with those of the standard folded radial forearm flap in head and neck reconstruction. There was no significant difference regarding harvesting time, operative time, blood loss, or compli-cations between the two methods.

The radial forearm flap provides some distinct advantages for head and neck reconstruction. It is a reliable and easily har-vested flap. Additionally, it offers thin and pliable soft tissue to meet the intricate requirements in head and neck reconstruc-tion. Under aesthetic and functional considerations, folded and bipaddled forearm flap was developed and has been commonly adopted.1,2 Bhathena stated that the bipaddled flap can be used as two or more separate paddles to simultaneously provide mucosa lining and skin cover.1 However, there is need with this procedure to de-epithelialize or to excise down to fascia the intervening skin segment between the two paddles, which may lead to injury of the vascular territories of the radial artery pedicle.1,2 Although the cadaveric study by Lamberty et al docu-mented that the skin vascular territories of the forearm provide an anatomical basis of bipaddling the forearm flap,3 anatomical variation of perforator characteristics still exists and is appar-ent.4 Therefore, an intraoperative technique is necessary for identifying the vascular plexus to facilitate free-style flap design.

Several methods for intraoperative vascular exploration have been reported. In a case series containing 15 patients, Sacks et al used laser-assisted near-infrared indocyanine green angiogra-phy to intraoperatively localize the perforator perfusion zones for assisting immediate anterolateral thigh flap design.9 In a case report of a conjoined anterolateral thigh and tensor fascia latae perforator, Buehrer et al proposed similar modality utiliz-ing intraoperative indocyanine green monitoring to identify a sufficient perforasome before flap harvesting and also to assess the vascular flow after anastomoses.10 Sacks et al stated that the laser-assisted indocyanine green angiography can provide real-time, intraoperative, and quantitative information to optimize anterolateral thigh flap design and that the handheld Doppler was not used to identify the perforator preoperatively.9 In com-parison, indocyanine green angiography is evidently more com-plicated than the transillumination method.

The transillumination method has been applied in many aspects, including in venipuncture, examination of hydrocele, and identification of mesenteric vascular network.5–7 The intra-operative transillumination method demonstrated in this study had the same characteristics as these applications. First, the light source can very simply and sufficiently be a fully charged pen-light. Second, the method can be performed under naked eyes without any further analysis. Most importantly, the intraopera-tive transillumination method can allow plastic surgeons to be more confident in dividing and shaping the forearm flap in a free-style manner. Although this study revealed no significant differ-ence in perioperative outcomes and complications between the two groups, the negative results should not reduce the value of the transillumination method. As the transillumination method can help surgeons to design a more delicate flap for each unique defect, it might have an effect on patients’ satisfaction rather than on clinical outcomes. Future studies are needed to further explore the effect of the transillumination method on patients’ satisfaction, function, and quality of life.

The different diagnoses between the case and control groups mainly stemmed from the different reconstruction needs of the anatomical areas. The removal of buccal, gingival, or palate can-cers usually results in a large defect, which only indicates flap cov-erage. Conversely, the removal of tongue or mouth floor cancer usually results in a more complicated defect because reconstruction

Table

Demographic characteristics, flap characteristics, and surgical information of the case (transillumination method) and control (standard procedure) groups

VariablesCase group

(n = 12)Control group

(n = 12) p

Age, y 54 (49-67) 54 (48-65) 0.744Gendera 1.000 Male 11 (91.7) 11 (91.7) Female 1 (8.3) 1 (8.3) Diagnosisa <0.001 Buccal cancer 0 (0) 5 (41.7) Gingival cancer 0 (0) 3 (25.0) Palate cancer 0 (0) 2 (16.7) Tongue cancer 8 (66.7) 1 (8.3) Mouth floor cancer 4 (33.3) 1 (8.3) TNM stage 0.526 I 2 (16.7) 1 (8.3) II 6 (50.0) 4 (33.3) III 4 (33.3) 7 (58.3) IV 0 (0) 0 (0) Flap size, cm2 42 (35-58) 45 (30-53) 0.486 26 (23-34);

17 (15-24)b

Harvesting time, min 95 (55-100) 70 (60-90) 0.342Operative time, min 345 (300-375) 355 (300-390) 0.805Blood loss, mL 30 (20-50) 30 (20-40) 0.640Donor site complicationa 0 (0) 0 (0) NARecipient site complicationa Hematoma 0 (0) 0 (0) NA Infection 0 (0) 1 (8.3) 1.000 Dehiscence 1 (8.3) 0 (0) 1.000 Partial necrosis 0 (0) 0 (0) NA Flap failure 1 (8.3) 0 (0) 1.000 Revision 1 (8.3) 1 (8.3) 1.000Period of follow-up, mo 7.4 (4.5-8.9) 6.8 (3.3-10.5) 0.504

NA = not available.aData were presented as median (interquartile range) or count (percentage).bThe data indicated the sizes of the final two divided flaps.

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of the tongue is much more difficult to achieve. The goal of recon-struction of the tongue is to restore swallowing function, protect the airway, facilitate articulation, and provide sufficient bulk to fill the oral cavity.11,12 Thus, reconstruction of the tongue usually warrants a more delicately designed flap. Surgical requirements of tongue or mouth floor cancers are discernably more complex than that of buccal, gingival, or palate cancers. Therefore, com-parison of these two groups might underestimate the effect of the transillumination method, which might be the reason of the nega-tive results in this study. Further investigations are warranted to study the potential benefit of the transillumination method.

There are several limitations of this study. First, owing to the retrospective study design, potential selection bias and report bias could not be avoided. Second, the sample size was small and all patients were operated on by the same plastic surgeon, which decrease the external validity of this study.

In conclusion, the transillumination method can allow plastic surgeons to easily identify the perforator vascular plexus of the radial forearm flap, which facilitates intraoperative flap design in head and neck reconstruction without increasing harvesting time and postoperative complications.

REFERENCES 1. Bhathena HM, Kavarana NM. Folded, bipaddled composite flap in head

and neck reconstruction. Head Neck 1990;12:386–91.

2. Savant DN, Patel SG, Deshmukh SP, Gujarati R, Bhathena HM, Kavarana NM. Folded free radial forearm flap for reconstruction of full-thickness defects of the cheek. Head Neck 1995;17:293–6.

3. Lamberty BG, Cormack GC. The forearm angiotomes. Br J Plast Surg 1982;35:420–9.

4. Heitmann C, Khan FN, Levin LS. Vasculature of the peroneal artery: an anatomic study focused on the perforator vessels. J Reconstr Microsurg 2003;19:157–62.

5. Cai EZ, Sankaran K, Tan M, Chan YH, Lim TC. Pen torch transillumi-nation: difficult venepuncture made easy. World J Surg 2017;41:2401–8.

6. Keihani S, Hojjat A, Kajbafzadeh AM. Abdominoscrotal hydrocele: role of physical exam and transillumination in diagnosis. J Pediatr 2015;167:1448–e1.

7. Liu YS, Chen HC, Chung KP, Li TS. Transillumination instrument facil-itates faster and more accurate dissection of right colon segment for oesophageal reconstruction. Asian J Surg 2010;33:94–6.

8. Kuhns LR, Martin AJ, Gildersleeve S, Poznanski AK. Intense transillumi-nation for infant venipuncture. Radiology 1975;116:734–5.

9. Sacks JM, Nguyen AT, Broyles JM, Yu P, Valerio IL, Baumann DP. Near-infrared laser-assisted indocyanine green imaging for optimizing the design of the anterolateral thigh flap. Eplasty 2012;12:e30.

10. Buehrer G, Taeger CD, Ludolph I, Horch RE, Beier JP. Intraoperative flap design using ICG monitoring of a conjoined fabricated anterolateral thigh/tensor fasciae latae perforator flap in a case of extensive soft tissue reconstruction at the lower extremity. Microsurgery 2016;36:684–8.

11. Levis C, Hynes N, Archibald S. Through and through defects of the lower face. Clin Plast Surg 2005;32:327–37, v–vi.

12. Neligan PC. Head and neck reconstruction. Plast Reconstr Surg 2013;131:260e–9e.

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