Application of a jigsaw puzzle flap based on free-style perforator to repair large scalp defects after tumor resection: A case series

Dojing Yu, Jing Wng, Lei Chen, Lu An, Yhui Feng, Sheng Jing,Shuyu Zhng, Xioming Chen, Guozhong Lv

a Department of Plastic and Burn Surgery, The Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, Chengdu 610051, Sichuan, China

b Transformation Center of Radiological Medicine, The Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu, China

c Center of Burn and Trauma, Affiliated Hospital of Jiangnan University, Wuxi 214122, Jiangsu, China

Keywords:Scalp defect Free-style perforator Jigsaw puzzle flap

A B S T R A C T

1.Introduction

Scalp malignancies, such as basal cell carcinoma, cutaneous squamous cell carcinoma, and malignant melanoma, are common diseases.1The reconstruction of a large scalp defect after extended tumor resection is challenging for both plastic and craniofacial surgeons.2–4However,over the past years, some strategies have gradually been formulated to repair large scalp defects.5–11These strategies include expander-based reconstructions, which can provide a flap of sufficient size, preserving vascularity, and match the local tissue, and free musculocutaneous flap approaches, which provide an adequate volume of tissue to cover the defect in a single stage.2,4,6,10

However, the scalp is an exposed part of the body and a unique aesthetic organ because of the presence of hair;thus,the ultimate goal in repairing scalp defects includes not only covering the defect and restoring function but also obtaining excellent aesthetic outcomes.12Most notably, free musculocutaneous flaps cannot match the residual scalp with better aesthetic outcomes.Using such flaps also poses a high risk of arterial embolism, which may require further surgical intervention.13In the conventional local random flap approach, the range of motion in covering the defect is limited.More importantly,in the case of local large random scalp flaps, the donor site defect cannot effectively close on its own,always requiring the use of free skin transfer.However,this approach results in poor aesthetic and functional outcomes.Moreover, expander-based reconstruction is time-consuming and may not be suitable for malignant tumors.While employing dilators, serious complications,such as ulcers,thinning,and necrosis,may threaten the entire treatment.14Therefore,it is important to design a novel flap of sufficient size to promptly cover a large scalp defect and that can match the surrounding residual scalp tissue with direct closure of the donor site.

The free-style perforator flap provides an almost unlimited number of options for reconstruction because it provides a reliable blood supply and greater freedom in choosing a donor-site area.15–20Free-style perforator flaps are constructed regardless of the anatomical variations of their vessels,which suggests that any island flap can be harvested and tailored to versatile shapes provided a supply vessel is identified and dissected.

Therefore, designing a jigsaw puzzle flap based on a free-style perforator could be beneficial for large scalp defects.This approach can be considered a valid alternative to conventional methods.Ultimately,our design provided excellent matches in color, texture, and structural characteristics with the residual scalp.

2.Methods

2.1.Patient information

Thirty-five patients(19 men and 16 women)underwent jigsaw puzzle flap procedures based on a free-style perforator to repair large scalp defects from May 2013 to November 2022 (Table 1).The patients were aged 42–85 years.General anesthesia was used for most of the patients;only three patients who were in a healthy condition underwent the procedure under local anesthesia.

2.2.Preoperative design

The size,shape,and location of the defect after tumor resection were assessed preoperatively.A portable Doppler ultrasound detector(Smartdop 45; Hadeco, Inc., Kawasaki, Japan) was used to explore the underlying perforators in the scalp around the defect.In a few cases,no or very few perforator vessels could be detected around the wound using this portable Doppler ultrasound,and color Doppler flow imaging(CDFI)was used instead.Several donor areas were preferably selected based on the exploration,and more than two perforators in an ideal position were detected and marked on each donor area.Following the principles of the jigsaw puzzle flap design concept,based on the of the Doppler-detected positions of the perforators and on the requirement that the donor area can be pulled and sutured directly,the“template paper”of a large scalp defect was divided into smaller perforator flaps of smaller areas and varying shapes.The small flaps were transferred to the defect, with the location of the perforator(the loudest point of the blood vessel signal)as the rotation point.After recombination, the total area employed was slightly larger than the defect to facilitate adjustment and modification during the surgical procedure.The perforator was designed as eccentrically as possible and was located on one side of the flap to form a perforator propeller flap,V-Y advancement flap,or rotation flap based on the perforator(Fig.1A).

2.3.Flap harvest

Based on the different sites and tolerance of the patient, general or local anesthesia was selected,and the corresponding extended resection was carried out according to the report of the rapid pathological examination performed during the operation.According to the size and shape of the actual defect during surgery,the large defect corresponding to the preoperative flap was divided into several smaller parts corresponding to each small perforator flap.Through repeated mimicking, the preoperative flap design was adjusted and marked using a paper template.An incision was made along one side of the designed skin flap extending tothe loose surface of the galea aponeurotica layer, which is located between the two selected perforators, to locate the perforators detected preoperatively.During the operation,silk sutures were used to stitch and pull the scalp flap tissue on the incised side.The scalp flap was carefully lifted while maintaining tension to locate the perforator.When the perforator was located(the diameter of the perforator was>0.3 mm),the operation was continued according to the original plan; otherwise,another spare perforator was located by investigating along the direction opposite to that of the incision.We released the perforator from the exit point of the surface layer of the galea aponeurotica using microscissors and retained a fascial pedicle approximately 0.5 cm around the perforator.The vascular pedicle of the perforator was dissected retrogradely to a suitable length to form a free-style perforator flap.Similarly,the other perforator flaps were harvested(Fig.1B).

Table 1 Demographic information of the 35 patients.

Table 1 (continued)

2.4.Flap transfer

All component flaps were mobilized to the defect to observe whether the pedicle of the blood vessel had any obvious distortion, bending, or blood flow disturbances at the distal end of the flap.In case of inadequate blood supply, a prompt assessment of the pedicle was essential.If the pedicle was twisted and bent, the perforators were further dissected to obtain a longer vascular pedicle.If the pedicle was normal,warm saline gauze was used to cover the flap and pedicle,and the changing trend of distal blood flow on the flap was observed.After confirming that the blood supply of the flaps was good,they were mobilized to the defect and sutured to each other to create a new larger jigsaw puzzle-like flap to cover the scalp defect.Finally, all donor sites were closed directly(Fig.1C and 1D).

2.5.Postoperative treatment

A routine intravenous drip of dexamethasone (5–10 mg/d) and a papaverine intramuscular injection (30 mg every 8 h for 3 days) were administered.A light pressure bandage was applied,with maintenance of the flap observation window and observation of the temperature, color,and capillary reaction of the skin flap once every 6 h.If the blood supply was poor, symptomatic treatment, such as vasodilators and vacuum sealing drainage (VSD), was used.One end of a semicircular elastic rubber tube drainage strip was placed under the flaps and these were covered with a VSD, forming a negative pressure system between the deep cavity under the flaps and the VSD covering the flaps.The accumulation of fluid under the skin flap was promptly attracted,which made the flaps closely adhere to the wound base and helped revascularize the area between the flaps and the wound base.Aspiration was performed at a negative pressure of 125–130 mmHg that was intermittently closed.Physiological saline was injected into the VSD,the negative pressure was closed,soaking was allowed for 15 min,and then the physiological saline was aspirated.This soaking was repeated 3–5 times a day.This alternating attraction and immersion had a similar effect to physical massage, which could promote venous reflux of the skin flap, inhibit congestion, and prevent tissue necrosis caused by prolonged and high pressure on the flaps.The stitches were normally removed 10 days postoperatively.

Fig.1.Schematic diagram of the reconstruction of a large scalp defect near the occiput with a jigsaw puzzle flap based on free-style perforator.(A)Portable Doppler ultrasound for exploring the underlying perforators around the scalp defect,and marking the position of the perforator flaps.(B)Harvesting of the perforator flaps.(C)Transfer of the perforator flaps to the recipient area to repair the wound.(D) Suturing and closure of the donor site.

3.Results

A total of 35 patients were treated.The average defect size was 72 cm2(range, 25–91 cm2).Overall, 105 component flaps based on free-style perforators were harvested.The sizes of the component flaps ranged from 4.0 cm × 2.0 cm–5.0 cm × 12.0 cm, and the diameters of the perforator vessels on the pedicles ranged 0.6–3.0 mm.In our surgical procedures, the number of perforator flaps administered ranged from a minimum of two to a maximum of four in a single patient.Among all flaps,101 survived well, 3 had blood stasis due to obstruction in the venous return with partial necrosis and healed 4 weeks after acupuncture and dressing application,and 1 flap exhibited undesirable healing because of excessive tension and healed 10 days after dressing application.All flaps had a satisfactory appearance after the follow-up periods of 6 months–10 years.One patient experienced local tumor recurrence.

3.1.Typical case

A 49-year-old male patient was admitted to the hospital because of gradual enlargement of a lesion between the scalp and left ear for 5 years and repeated ulceration for 1 year, which was diagnosed as basal cell carcinoma.On examination,the lesion was located on the scalp behind the left ear and measured approximately 10.0 cm × 7.5 cm.After the tumor was completely resected, the defect on the auricle and scalp was approximately 10.5 cm×8.0 cm.We designed a jigsaw puzzle flap based on freestyle perforators to repair the scalp defect.The component perforator flaps were approximately 6.5 cm × 8.0 cm and 4.5 cm × 8.0 cm.The postoperative appearance was satisfactory,and 1.5 years of follow-up revealed no tumor recurrence(Figs.1 and 2).

4.Discussion

Designing an appropriate flap for resurfacing large scalp defects remains a clinical conundrum.The scalp is a unique aesthetic organ owing to the presence of hair,and the ultimate goals in repairing scalp defects include not only covering the defect and restoring function, but also obtaining excellent aesthetic outcomes.The scalp covers the skull and protects the craniocerebral organs,and hair is its unique appendage that plays an important role in cosmetic decoration.12Homogeneous replacement tissue from other parts of the body are unsuitable for repairing scalp defects.For small scalp defects, the donor area can be closed directly after scalp flap transfer.6However,for large scalp defects,the donor area cannot be sutured directly after transferring the larger area of scalp flap because of the poor range of motion of the scalp;therefore, free skin grafting is often required.5–9Although scalp expansion is preferred for homogeneous repair of large scalp defects, this technique is time-consuming and may contribute to tumor invasion,contraindicating its application in repairing large scalp defects after tumor resection.2,6,10Additionally, this method requires a secondary operation.In summary,the most commonly used techniques remain skin grafting and free flap transplantation for large scalp defects; however,these methods do not meet aesthetic repair rules,such as having the same origin, thickness, and texture.Moreover, these techniques lead to additional damage to the donor area.11Hence, we introduced a novel approach for the treatment of large scalp defects using a jigsaw puzzle flap based on a free-style perforator approach with favorable results.

With the development of modern reconstructive surgery, the freestyle perforator flap provides an almost unlimited number of options for reconstruction because it provides a reliable blood supply and greater freedom in choosing a donor-site area.21–23Free-style perforator flaps are constructed according to Doppler mapping before decisions for the operative strategy are made, and they are performed by a retrograde dissection method during surgery,regardless of the anatomical variations of their vessels, suggesting that any island flap could be harvested and tailored to versatile shapes provided a supply vessel is identified and dissected.24,25More importantly,the blood supply of the scalp comprises the superficial temporal vessels on both sides,the supraorbital vessels in the forehead, the posterior occipital vessels in the neck, and their branches.These vessels interconnect through communicative branches,establishing a blood supply network on the scalp with a radial orientation from the periphery to the center and additional communication with each other.The vessel network is the anatomical basis and “source” of free-style perforator scalp flaps.Therefore,we designed a novel surgical procedure to repair large scalp defects using a jigsaw puzzle scalpel flap based on free-style perforators.

Fig.2.Surgical procedures for basal cell carcinoma on the scalp behind the left ear.(A)Basal cell carcinoma of the scalp behind the left ear.(B)Defect behind the ear after resection.(C)A component free-style perforator flap of the jigsaw puzzle flap.(D)Harvesting of the perforator flap.(E)Mobilization of component flaps to create a new and large jigsaw puzzle flap.(F) Jigsaw puzzle flap repair of the large defect with direct closure on the donor site.

When separating the vascular pedicle of the free-style perforator flap,the branches of the perforator,rather than the main blood vessel,should be dissected, which has the advantage of shorter surgical time, less trauma, and direct closure of the donor area.26The main operational experiences of jigsaw puzzle scalpel flaps based on free-style perforators are as follows.First,with the advancement of vessel detection technology using ultrasound Doppler,a single small perforator vessel can be located preoperatively.We marked all skin penetration points with a velocity of>2.5 cm/s in the area rather than focusing on the source vessels(superior vessels) of the perforators using a Smartdop 45 Doppler before surgery,and the angle between the probe and skin was set at 60°.Only one free-style perforator was used as the blood supply for the flap.More importantly, to reduce the false-positive rate, the chosen perforator should be checked at several orientations that correspond to the scalp vascular features to ensure reliability.Second, Doppler sonography can offer precision, provide information on the axis of the perforators, and can be used as a unique tool for preoperative diagnosis in most cases.The vessel with the strongest Doppler signal can then be identified and traced retrogradely until adequate mobility of the flap is generated for pedicle creation.The remaining weak Doppler signals can help to determine the limits of the size and orientation of the axis for the anticipated flap based on the adjacent perforator vascular territory.27Thus,it is vital to map all perforators in the scalp adjacent to the defect using the Doppler device before determining the surgical strategy.In addition,we only harvested each small flap’s safety margin in the adjacent perforator vascular territory and did not include a third perforasome for a single pedicle perforator, based on the reports by Saint-Cyr and Aydin.19,27Third, the location and protection of the perforator during surgery is also a key point for a successful surgical procedure.Owing to the high perfusion pressure and large amount of blood in the scalp,to maintain a clear visual field, norepinephrine (1:200 000 units) was often injected into the shallow and deep layers of the scalp at the incision region to reduce bleeding,and then the relatively loose surface of the galea aponeurotica layer was incised.The scalp and surface tissue of the galea aponeurotica layer were sutured with silk, and long silk was reserved to drag for locating and separating perforator vessels.While the operator lifted the scalp flap with slight tension using reserved silk,the assistant maintained the base of the donor site in tension,and a pen-tip electric knife was used to separate the scalp flap under low-energy conditions to locate the perforating branch (according to the preoperative location).When we found the perforator branch corresponding to the location of the perforating branch and the diameter of the perforating branch was suitable(>0.3 mm),we released the perforator from the perforation point of the aponeurosis layer with microscissors and retained the fascial pedicle approximately 0.5 cm around the perforator.The perforator vessel pedicle was then dissected retrogradely to the appropriate length to form the free perforator flap.If it was determined that there was a perforating branch in the fascia pedicle that did not affect the rotation of the flap,the small perforating branch around the perforating branch was retained as far as possible to form a “perforator bundle” to facilitate venous reflux.During this operation, hemostasis of the operational field needs to be thorough and timely.In addition,the patient’s blood pressure should be maintained at a low level to reduce bleeding as much as possible.Finally,there were sometimes arteries with no concomitant veins on the scalp.Therefore, when dissecting the perforator pedicle, the operator should ensure that there is a vein perforator in the fascia pedicle and try to retain the small perforator around the main perforator to form a “perforator bundle”to facilitate venous reflux.If venous congestion is suspected after the flap operation,a VSD should be placed over the flap to prevent and treat mild congestion with a valve window on the VSD to observe the blood supply of the flap.

There were several advantages of our method.First, we successfully repaired large scalp defects with homogeneous tissue by making the best use of the residual scalp.Second,we could shift the conventional attention focused on identifying a large flap for large scalp defects to dividing the large defect into several small appropriate units that could result in direct closure of the scalp donor site with an aesthetic outcome and minimal invasion.Finally, large scalp defects could be repaired using a single-stage approach with aesthetic outcomes.

However, our approach cannot be used to repair very large defects comprising more than half of the total scalp.Additionally,our follow-up in the later stages mainly involved face-to-face visits, phone calls, and online methods.During the follow-up period,the focus was on whether the tumor recurred, the flaps showed necrosis, and the scars were obvious.Unfortunately, we did not focus on retaining standard photographs after completely shaving off the patients’hair.Therefore,we were unable to provide other satisfactory photos.Additionally,our study could not overcome the limitations inherent to the perforator flap procedure.An increase in operative time is inevitable because of the necessity of dissections for free-style perforators.Nevertheless, avoiding microsuturing of vessels can reduce the total operative time.Moreover,better outcomes obtained without free skin transfer should shorten the patient’s hospital stay.Finally, it is difficult to obtain validation through a randomized controlled trial.However,the present method is promising and can be regarded as a true alternative for the treatment of large scalp defects.

5.Conclusion

For the reconstruction of large scalp defects after resection, using a jigsaw puzzle flap based on a free-style perforator can be considered a suitable option,yielding satisfactory functional and cosmetic results.

Ethics approval and consent to participate

This study was approved by the Institutional Review Boards/Ethics Committees of the Second Affiliated Hospital of Soochow University and the Second Affiliated Hospital of Chengdu Medical College(approval nos.KJ20210035 and KJ2021041).All participants or their guardians provided written informed consent before study enrolment.

Consent for publication

The patients included in this study gave written informed consent to the publication of the data contained in this study.

Authors’ contributions

Yu D: Conceptualization, Methodology, Writing-Review and editing,Funding acquisition.Wang J:Methodology,Writing-Original draft,Data curation.Chen L: Methodology, Data curation.An L: Data curation,Writing-Original draft.Feng Y: Writing-Review and editing, Funding acquisition.Jang S: Project administration, Data curation.Zhang S:Project administration, Funding acquisition.Chen X: Data curation,Methodology.Lv G: Writing-Review and editing.

Declaration of competing interests

The authors declare that they have no competing interests.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (grant nos.32071238, 82073477, and 82103773), Natural Science Project of Chengdu Medical College(grant nos.CYZZD20-01 and CYZ19-31), Science and Technology Project of Health Commission of Sichuan Province (grant no.21PJ158), Scientific Research Fund Project of China Baoyuan Investment Co.,Ltd.(grant no.CBYI202104),Nuclear Medical Science and Technology Innovation Project of China National Nuclear Corporation Medical Industry Management Co., Ltd.(grant no.ZHYLTD2021002),and Young Talent Project of China National Nuclear Corporation.