Volumetric Analysis of a Novel Chimeric Gracilis and Profunda Artery Perforator Flap

• Abstract
• Methods
• Results
• Discussion
• Conclusion
• References

Abstract

Background The presence of a chimeric gracilis and profunda artery perforator (PAP) flap with a common arterial pedicle has been demonstrated on computed tomography angiography in up to 59% of patients and confirmed in a cadaveric model. Already utilized for head and neck reconstruction by Heredero et al, this novel flap could provide more volume than either flap alone which is advantageous, particularly in patients with sizable defects. The purpose of this study was to determine the average tissue volume that can be utilized from this chimeric flap.

Methods CT Angiogram imaging studies exhibiting chimeric flap anatomy were reviewed over a 7-year period at a single institution utilizing Visage Version 7.1, a radiology picture archiving and communication system. This software was used to trace the flap pedicles and to capture estimated soft tissue volumes of each respective flap.

Results A total of 31 patients, consisting of 52 lower extremity gracilis and PAP chimeric flaps, underwent tissue volume analysis. The average total volume of soft tissue supplied by the gracilis flap was found to be 70.21 cm³ (standard deviation [SD] = 26.99). The average volume of the PAP flap was 31.73 cm³ (SD = 26.12). The average total volume captured by the chimeric gracilis and PAP flap was 101.94 cm³ (SD = 62.40).

Conclusion The potential soft tissue volume that can be harvested from a chimeric gracilis and PAP flap is significantly greater than solitary gracilis or PAP flaps. This chimeric flap may serve as a viable and advantageous reconstructive option for patients requiring large volume soft tissue coverage, particularly if other sizable options are not available.

Our institution has previously described an anatomic variation which allows for the design of a chimeric gracilis and profunda artery perforator (PAP) flap with a common arterial pedicle ([Fig. 1]).[1] [2] The presence of this common pedicle has been demonstrated through both computed tomography angiography (CTA)[1] and cadaveric evaluation,[2] found to be present in approximately 51 to 59% of patients.[1] [2] Due to its chimeric design, this flap may potentially offer greater soft tissue volume than either a singular gracilis or PAP flap, providing flexibility for reconstruction, especially in scenarios featuring a large defect. Clinical utility of this flap has been demonstrated by both Heredero et al[3] and Yao et al[4] in large-volume head and neck reconstruction as well as in perineal reconstruction.[5] [6] [7]

Despite the utility of the combined flap, the identification, dissection, and microsurgical anastomosis (if used as a free flap) of two distinct pedicles represents a significant disadvantage of prolonged operative time, greater risk of anastomotic complications, and resources. As we have previously demonstrated feasibility of a chimeric flap harvest in cadaveric models,[2] preoperative mapping through CTA could allow for identification of a common arterial pedicle and improve preoperative planning and resource utilization. The primary purpose of this study is to radiographically evaluate the potential soft tissue volume of this chimeric medial thigh flap.

Methods

CTA studies of patients with a common arterial pedicle supplying both gracilis and PAP flaps were retrospectively reviewed. Study evaluators underwent software training for Visage Version 7.1 (Visage Imaging Inc., San Diego, CA), a radiology picture archiving and communication system, supervised by a board-certified radiologist. Visage, a semiautomated vessel-tracing algorithm, was used to trace out the relevant arterial anatomy of the common pedicle from its origin at the profunda femoris to insertion within corresponding gracilis and PAP flap tissues ([Fig. 2]). Once the arterial anatomy was adequately traced, 3D postprocessing was utilized to capture an estimate of individual soft tissue volume supplied by the pedicle for the gracilis myocutaneous flap and PAP flap soft tissues; the sum of these two values was used to determine the calculated volume of a harvested chimeric flap. Tissue volume measurement was attenuation-based, utilizing the tissue growing region of interest tool in Visage software, with soft tissue regions of interest including the angiosomes of associated gracilis and PAP pedicles. Primary endpoints of analysis included the following: gracilis muscle volume (cm³), gracilis overlying fat volume (cm³), PAP flap soft tissue volume (cm³), and volume of gracilis and PAP flap soft tissue added together (cm³; [Fig. 3]). Imaging studies with insufficient image quality to perform 3D tissue volume measurement (poor angiogram contrast timing precluding pedicle tracing, significant streak artifact, or overall poor image quality) were excluded from analysis.

Results

A total of 51 patients were included in radiographic analysis. Of these 51 patients, 16 were deemed to have unsatisfactory radiographic imaging and were excluded from analysis. This left 35 patients, consisting of 52 lower extremity gracilis and PAP chimeric flaps for soft tissue volume analysis. The average total volume supplied by the gracilis flap alone was found to be 70.21 cm³ (standard deviation [SD] = 26.99). The average volume of soft tissue of the PAP flap alone was 31.73 cm³ (SD = 26.12). The average total volume captured by the chimeric gracilis and PAP flap was 101.94 cm³ (SD = 62.40).

Discussion

We have previously described the presence, prevalence, and harvest feasibility of a novel chimeric gracilis and PAP flap.[1] [2] This study further elaborates on earlier work, describing the average volume that may potentially be harvested using the chimeric flap. It is not uncommon in modern day for plastic surgeons to face the need for reconstruction of large volumes of soft tissue in the setting of trauma or cancer reconstruction. A greater understanding of flap volume allows for improved preoperative planning and patient selection based on size needed for adequate soft tissue reconstruction. This is the first study to evaluate soft tissue volume that can potentially be harvested from a chimeric gracilis and PAP flap.

One significant area where the chimeric flap could offer significant value and versatility to surgeons is breast reconstruction. Within the field of breast reconstruction, comparison of deep inferior epigastric perforator (DIEP) flap and PAP flaps has yielded similar patient satisfaction between both options, with the caveat of the PAP flap yielding a significantly smaller tissue amount.[8] This has led to the PAP flap being described for small volume breast reconstruction in thin patients,[9] or as a stacked option in the scenario of an unavailable DIEP flap.[10] Furthermore, the Transverse upper gracilis profunda artery perforator (TUGPAP) flap has already been shown to be a viable option within breast reconstruction.[11] [12] [13] [14] Therefore, it stands to reason when a PAP or bipedicled Transverse upper gracilis profunda artery perforator (TUGPAP) flap is already being considered, preoperative imaging to determine presence of a common perforator may be of significant value. As we have demonstrated, a chimeric flap may offer greater versatility in reconstruction than a single PAP flap due to greater volume. Utilization of a chimeric flap may also be efficient as a single anastomosis rather than a bipedicle or stacked option would decrease operative time and thereby save on the significant cost of time in the operating room.[15]

Additionally, due to the well-hidden scar location on the upper inner thigh for a chimeric flap, preoperative imaging could make this flap an option for those patients who desire autologous reconstruction with low donor site morbidity. One consideration that must be addressed is the flap design and closure of the donor site. Although the scar is often well-hidden with thigh-based flaps, these flaps can be prone to wound healing problems, and this must be accounted for in flap design to prevent complications at the donor site. The authors propose designing the flap in a boomerang-style shape as previously described by senior surgeons at our institution. In this design, the transverse skin paddle is based superiorly at the groin crease then transitioning to a vertical component centered over the gracilis muscle.[16] This design has several advantages. First, this design allows the surgeon to optimize the capture of many cutaneous perforators increasing flap reliability. Second, by curving the incisions in this manner, donor site closure is more easily facilitated without undue tension at the donor site and can be closed in a V-Y (in which a v-shaped incision is made to advance tissue. The site is then closed which gives the appearance of a y-shaped suture line) fashion.

There must be a careful balance between achieving increased soft tissue volume with chimeric flap harvest with that of ensuring the ability to close the donor site while preventing unwanted complications at the donor site. The results of this study are based on estimates of soft tissue based on measured perfusion from CTA imaging studies which may overestimate soft tissue volumes when compared with actual volume that can be safely harvested and closed primarily in a clinical setting. The software tracings are believed to be the maximum amount of soft tissue that could be harvested based on the common perforator, although the full amount may or may not likely be harvested in the clinical setting based on reconstructive need and feasibility of primary closure of the donor site. Therefore, a prospective study comparing these measurements to what may be harvested in a clinical setting is needed to validate this model.

The utility of the chimeric flap extends beyond breast reconstruction as demonstrated through reports of successful use in head and neck reconstruction.[3] [4] Both reports describe successful reinnervation and function of the harvested gracilis, with patients achieving satisfactory outcomes with regards to their speech and diet over a year postoperatively.[3] [4] One of the current most commonly selected flaps in in the realm of head and neck reconstruction is the anterolateral thigh (ALT) flap.[17] [18] Advantages include its versatility, ability to add additional pedicles, and minimal donor morbidity.[18] [19] However, some issues with the ALT flap have been described notably, including excess bulk.[19] Based on the volumetric results of this study the chimeric gracilis flap may offer an attractive alternative option when less bulk is desired. The average chimeric flap volume was found to be 101.94 cm³ (SD = 62.40). A previous series has reported average ALT volume to be larger at 139 cm³ for thinned flaps and 199 cm³ for standard ALT flaps.[20]

Our previous studies have found the common perforator to be present in 51 to 59%[1] [2] of patients, and we have now demonstrated that it has enough volume to be versatile without being overly bulky. In patients where the chimeric flap would offer satisfactory reconstruction, preoperative imaging for identification of a potential common perforator should be strongly considered. If such a perforator is identified, this flap adds to the arsenal of reconstructive options available for plastic surgeons.

There are limitations to this study that must be acknowledged. First, the sample size of our cohort was small, making generalizability of the study difficult to ascertain. Additionally, although measures were taken to ensure that the data collection and radiographic analysis of our study was as objective as possible, the data collection was subjective in nature, as the volumetric estimation is ultimately based on one user's capture with the software system. We did our best to limit this subjectivity via multiple efforts such as software training with a board-certified radiologist and single user radiographic analysis to decrease variability in data collection. However, despite these efforts, ultimately, pedicle tracing and software estimation of soft tissue volume with this software was contingent upon determination by the user. Lastly, as mentioned previously, these results were based on soft tissue volume estimates based on software analysis from CTA imaging and were not based on flaps harvested in a clinical setting. Although this model has not yet been validated in a clinical setting, similar models have been shown effective in estimation of deep inferior epigastric perforator flap volume and/or size.[21] [22] Further studies are needed to compare what soft tissue volume can be achieved in the clinical setting while preventing complications at the donor site as well as to demonstrate the validity of the proposed CTA imaging-based model for estimating soft tissue harvest.

Conclusion

The average soft tissue volume that can potentially be harvested from a chimeric gracilis and PAP flap is significantly greater than one of these single flaps alone. As it has been demonstrated that patients with the anatomical variant of a common pedicle are readily present based on CTA imaging, this chimeric flap may serve as a viable and advantageous reconstructive option for patients requiring large volume soft tissue coverage. We recognize that CTA findings may not completely correlate with the clinical physiology of these flaps but do believe that the distinct perforasomes seen both on CTA and clinically demonstrate that harvesting both together will provide significantly more flap volume than either alone. Overall, the chimeric gracilis–PAP flap represents a versatile reconstructive option that yields substantial volume for future use in a clinical setting.

Conflict of Interest

None declared.

Acknowledgments

We would like to acknowledge the work and collaboration of our colleagues in Musculoskeletal Radiology at our institution for their aid in the work of this paper.

• References

• 1 Hammond JB, Flug JA, Foley BM. et al. A newly described, highly prevalent arterial pedicle perfuses both gracilis and profunda artery perforator flap tissues: an angiographic study of the medial thigh. J Reconstr Microsurg 2020; 36 (03) 177-181
  Thieme ConnectPubMedSearch in Google Scholar
• 2 Hammond JB, Teven CM, Flug JA. et al. The chimeric gracilis and profunda artery perforator flap: characterizing this novel flap configuration with angiography and a cadaveric model. J Reconstr Microsurg 2021; 37 (07) 617-621
  Thieme ConnectPubMedSearch in Google Scholar
• 3 Heredero S, Falguera-Uceda MI, Sanjuan-Sanjuan A, Dean A, Solivera J. Chimeric profunda artery perforator - gracilis flap: a computed tomographic angiography study and case report. Microsurgery 2021; 41 (03) 250-257
  CrossrefPubMedSearch in Google Scholar
• 4 Yao CMK, Jozaghi Y, Danker S. et al. The combined profunda artery perforator-gracilis flap for immediate facial reanimation and resurfacing of the radical parotidectomy defect. Microsurgery 2023; 43 (04) 309-315
  CrossrefPubMedSearch in Google Scholar
• 5 Ciudad P, Dower R, Nicoli F. et al. Pelvic-perineal reconstruction with the combined transverse upper gracilis and profunda artery perforator (TUG-PAP) flap. J Plast Reconstr Aesthet Surg 2016; 69 (04) 573-575
  CrossrefPubMedSearch in Google Scholar
• 6 Sharp O, Kapur S, Shaikh I, Rosich-Medina A, Haywood R. The combined use of pedicled profunda artery perforator and bilateral gracilis flaps for pelvic reconstruction: a cohort study. J Plast Reconstr Aesthet Surg 2021; 74 (10) 2654-2663
  CrossrefPubMedSearch in Google Scholar
• 7 Kosutic D, Tsapralis N, Gubbala P, Smith M. Reconstruction of critically-sized perineal defect with perforator flap puzzle technique: a case report. Case Reports Plast Surg Hand Surg 2019; 6 (01) 38-42
  CrossrefPubMedSearch in Google Scholar
• 8 Murphy DC, Figus A, Stocco C, Razzano S. A comparison of patient reported outcome measures in patients who received both DIEP flap and PAP flap breast reconstructions. J Plast Reconstr Aesthet Surg 2019; 72 (04) 685-710
  CrossrefPubMedSearch in Google Scholar
• 9. Jo T, Jeon DN, Han HH. The PAP flap breast reconstruction: a practical option for slim patients. J Reconstr Microsurg 2022; 38 (01) 27-33
  Thieme ConnectPubMedSearch in Google Scholar
• 10 Haddock NT, Cho MJ, Gassman A, Teotia SS. Stacked profunda artery perforator flap for breast reconstruction in failed or unavailable deep inferior epigastric perforator flap. Plast Reconstr Surg 2019; 143 (03) 488e-494e
  CrossrefPubMedSearch in Google Scholar
• 11 Ciudad P, Maruccia M, Orfaniotis G. et al. The combined transverse upper gracilis and profunda artery perforator (TUGPAP) flap for breast reconstruction. Microsurgery 2016; 36 (05) 359-366
  CrossrefPubMedSearch in Google Scholar
• 12 Ciudad P, Huang TC, Manrique OJ. et al. Expanding the applications of the combined transverse upper gracilis and profunda artery perforator (TUGPAP) flap for extensive defects. Microsurgery 2019; 39 (04) 316-325
  CrossrefPubMedSearch in Google Scholar
• 13 Bodin F, Dissaux C, Dupret-Bories A, Schohn T, Fiquet C, Bruant-Rodier C. The transverse musculo-cutaneous gracilis flap for breast reconstruction: how to avoid complications. Microsurgery 2016; 36 (01) 42-48
  CrossrefPubMedSearch in Google Scholar
• 14. Karir A, Stein MJ, Zhang J. The conjoined TUGPAP flap for breast reconstruction: systematic review and illustrative anatomy. Plast Reconstr Surg Glob Open 2021; 9 (04) e3512
  CrossrefPubMedSearch in Google Scholar
• 15 Childers CP, Maggard-Gibbons M. Understanding costs of care in the operating room. JAMA Surg 2018; 153 (04) e176233
  CrossrefPubMedSearch in Google Scholar
• 16 Abdulwadood I, Pflibsen LR, Jarvis NR. et al. The PUG flap: conjoined profunda artery perforator and upper gracilis flap for breast reconstruction. Plast Reconstr Surg Glob Open 2024; 12 (03) e5544
  CrossrefPubMedSearch in Google Scholar
• 17 Wong CH, Wei FC. Microsurgical free flap in head and neck reconstruction. Head Neck 2010; 32 (09) 1236-1245
  CrossrefPubMedSearch in Google Scholar
• 18 Wong CH, Wei FC. Anterolateral thigh flap. Head Neck 2010; 32 (04) 529-540
  CrossrefPubMedSearch in Google Scholar
• 19 Shaw RJ, Batstone MD, Blackburn TK, Brown JS. The anterolateral thigh flap in head and neck reconstruction: “pearls and pitfalls”. Br J Oral Maxillofac Surg 2010; 48 (01) 5-10
  CrossrefPubMedSearch in Google Scholar
• 20 Ellabban MA, Elsayed MA, Zein AB. et al. Virtual planning of the anterolateral thigh free flap for heel reconstruction. Microsurgery 2022; 42 (05) 460-469
  CrossrefPubMedSearch in Google Scholar
• 21 Cerón MA, Duque JL, Verdoy SB. et al. Characterization of the volume and thickness of DIEP flap by CTA image processing. Paper presented at: XXIII Symposium on Image, Signal Processing and Artificial Vision. “XXIII Symposium on Image, Signal Processing and Artificial Vision.” 2021: 1-6 . ISBN 978-1-6654-1668-9/21. DOI: 10.1109/STSIVA53688.2021.9592004
  PubMedSearch in Google Scholar
• 22 Nanidis TG, Ridha H, Jallali N. The use of computed tomography for the estimation of DIEP flap weights in breast reconstruction: a simple mathematical formula. J Plast Reconstr Aesthet Surg 2014; 67 (10) 1352-1356
  CrossrefPubMedSearch in Google Scholar

Address for correspondence

Publication History

Received: 07 January 2024

Accepted: 15 April 2024

Accepted Manuscript online:
06 May 2024

Article published online:
31 May 2024

© 2024. Thieme. All rights reserved.

Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

• References

• 1 Hammond JB, Flug JA, Foley BM. et al. A newly described, highly prevalent arterial pedicle perfuses both gracilis and profunda artery perforator flap tissues: an angiographic study of the medial thigh. J Reconstr Microsurg 2020; 36 (03) 177-181
  Thieme ConnectPubMedSearch in Google Scholar
• 2 Hammond JB, Teven CM, Flug JA. et al. The chimeric gracilis and profunda artery perforator flap: characterizing this novel flap configuration with angiography and a cadaveric model. J Reconstr Microsurg 2021; 37 (07) 617-621
  Thieme ConnectPubMedSearch in Google Scholar
• 3 Heredero S, Falguera-Uceda MI, Sanjuan-Sanjuan A, Dean A, Solivera J. Chimeric profunda artery perforator - gracilis flap: a computed tomographic angiography study and case report. Microsurgery 2021; 41 (03) 250-257
  CrossrefPubMedSearch in Google Scholar
• 4 Yao CMK, Jozaghi Y, Danker S. et al. The combined profunda artery perforator-gracilis flap for immediate facial reanimation and resurfacing of the radical parotidectomy defect. Microsurgery 2023; 43 (04) 309-315
  CrossrefPubMedSearch in Google Scholar
• 5 Ciudad P, Dower R, Nicoli F. et al. Pelvic-perineal reconstruction with the combined transverse upper gracilis and profunda artery perforator (TUG-PAP) flap. J Plast Reconstr Aesthet Surg 2016; 69 (04) 573-575
  CrossrefPubMedSearch in Google Scholar
• 6 Sharp O, Kapur S, Shaikh I, Rosich-Medina A, Haywood R. The combined use of pedicled profunda artery perforator and bilateral gracilis flaps for pelvic reconstruction: a cohort study. J Plast Reconstr Aesthet Surg 2021; 74 (10) 2654-2663
  CrossrefPubMedSearch in Google Scholar
• 7 Kosutic D, Tsapralis N, Gubbala P, Smith M. Reconstruction of critically-sized perineal defect with perforator flap puzzle technique: a case report. Case Reports Plast Surg Hand Surg 2019; 6 (01) 38-42
  CrossrefPubMedSearch in Google Scholar
• 8 Murphy DC, Figus A, Stocco C, Razzano S. A comparison of patient reported outcome measures in patients who received both DIEP flap and PAP flap breast reconstructions. J Plast Reconstr Aesthet Surg 2019; 72 (04) 685-710
  CrossrefPubMedSearch in Google Scholar
• 9. Jo T, Jeon DN, Han HH. The PAP flap breast reconstruction: a practical option for slim patients. J Reconstr Microsurg 2022; 38 (01) 27-33
  Thieme ConnectPubMedSearch in Google Scholar
• 10 Haddock NT, Cho MJ, Gassman A, Teotia SS. Stacked profunda artery perforator flap for breast reconstruction in failed or unavailable deep inferior epigastric perforator flap. Plast Reconstr Surg 2019; 143 (03) 488e-494e
  CrossrefPubMedSearch in Google Scholar
• 11 Ciudad P, Maruccia M, Orfaniotis G. et al. The combined transverse upper gracilis and profunda artery perforator (TUGPAP) flap for breast reconstruction. Microsurgery 2016; 36 (05) 359-366
  CrossrefPubMedSearch in Google Scholar
• 12 Ciudad P, Huang TC, Manrique OJ. et al. Expanding the applications of the combined transverse upper gracilis and profunda artery perforator (TUGPAP) flap for extensive defects. Microsurgery 2019; 39 (04) 316-325
  CrossrefPubMedSearch in Google Scholar
• 13 Bodin F, Dissaux C, Dupret-Bories A, Schohn T, Fiquet C, Bruant-Rodier C. The transverse musculo-cutaneous gracilis flap for breast reconstruction: how to avoid complications. Microsurgery 2016; 36 (01) 42-48
  CrossrefPubMedSearch in Google Scholar
• 14. Karir A, Stein MJ, Zhang J. The conjoined TUGPAP flap for breast reconstruction: systematic review and illustrative anatomy. Plast Reconstr Surg Glob Open 2021; 9 (04) e3512
  CrossrefPubMedSearch in Google Scholar
• 15 Childers CP, Maggard-Gibbons M. Understanding costs of care in the operating room. JAMA Surg 2018; 153 (04) e176233
  CrossrefPubMedSearch in Google Scholar
• 16 Abdulwadood I, Pflibsen LR, Jarvis NR. et al. The PUG flap: conjoined profunda artery perforator and upper gracilis flap for breast reconstruction. Plast Reconstr Surg Glob Open 2024; 12 (03) e5544
  CrossrefPubMedSearch in Google Scholar
• 17 Wong CH, Wei FC. Microsurgical free flap in head and neck reconstruction. Head Neck 2010; 32 (09) 1236-1245
  CrossrefPubMedSearch in Google Scholar
• 18 Wong CH, Wei FC. Anterolateral thigh flap. Head Neck 2010; 32 (04) 529-540
  CrossrefPubMedSearch in Google Scholar
• 19 Shaw RJ, Batstone MD, Blackburn TK, Brown JS. The anterolateral thigh flap in head and neck reconstruction: “pearls and pitfalls”. Br J Oral Maxillofac Surg 2010; 48 (01) 5-10
  CrossrefPubMedSearch in Google Scholar
• 20 Ellabban MA, Elsayed MA, Zein AB. et al. Virtual planning of the anterolateral thigh free flap for heel reconstruction. Microsurgery 2022; 42 (05) 460-469
  CrossrefPubMedSearch in Google Scholar
• 21 Cerón MA, Duque JL, Verdoy SB. et al. Characterization of the volume and thickness of DIEP flap by CTA image processing. Paper presented at: XXIII Symposium on Image, Signal Processing and Artificial Vision. “XXIII Symposium on Image, Signal Processing and Artificial Vision.” 2021: 1-6 . ISBN 978-1-6654-1668-9/21. DOI: 10.1109/STSIVA53688.2021.9592004
  PubMedSearch in Google Scholar
• 22 Nanidis TG, Ridha H, Jallali N. The use of computed tomography for the estimation of DIEP flap weights in breast reconstruction: a simple mathematical formula. J Plast Reconstr Aesthet Surg 2014; 67 (10) 1352-1356
  CrossrefPubMedSearch in Google Scholar