INTRODUCTION
The Keystone flap was first described in 20031. It is an island flap based on fasciocutaneous perforators recruited from the periphery
of the wound to be treated. Thus, it has the reliable vascularization of a perforating
flap, combined with the simple dissection and reproducibility of a local flap2. Despite its advantages, it is still little mentioned in the specialized literature
and is far from becoming an option of choice in the clinical practice of reconstructive
surgery3.
OBJECTIVE
This article aims to present the experience of a highly complex oncology service in
the use of Keystone flaps in reconstructions. This series of cases aims to reinforce
this flap’s versatility and safety in managing defects of different volumes and locations.
METHODS
A retrospective study was developed by collecting data from the medical records of
patients operated on by the Plastic Surgery team of the Cancer Institute of the State
of São Paulo (ICESP) between February 2017 and January 2020. The following information
was collected: epidemiological data; histological type; comorbidities; location and
size of the resected area; hospitalization time; complications. Pre, intra and postoperative
photographic records were obtained.
RESULTS
A total of nine patients were treated with the Keystone flap (six women and three
men), with a mean age of 52.7 years, four hypertensives, three people with diabetes
and two smokers (Table 1). All defects followed after oncological resections, five in the lower extremities,
three in the trunk and one in the face. Melanoma was the most frequent neoplasm. The
mean resected area was 52.6cm2, with a median of 31.4cm2. In all cases, the donor area was closed primarily.
Table 1 - Clinical characteristics of nine patients with malignant skin lesions treated with
resection and reconstruction with a Keystone flap.
|
Genre |
Age |
Comorbidities |
Etiology |
Location |
Resected area |
Complications |
Anesthetic-surgical time |
Hospitalization time |
| N1 |
F |
71y |
SAH, DM, Depression, Obesity |
Transiting metastasis of melanoma |
L Leg |
19.77cm² |
- |
315 min |
3 days |
| N2 |
F |
73y |
Breast cancer |
SCC |
R Ankle |
31.4cm² |
- |
146 min |
2 days |
| N3 |
F |
54y |
Smoking, SAH, Depression |
Inguinal lymphadenectomy for metastatic melanoma |
R Inguinal |
21.3cm² |
- |
481 min |
3 days |
| N4 |
F |
76y |
SAH, obesity |
Infiltrative BCC |
L Nasolabial sulcus |
4.35cm² |
- |
238 min |
1 day |
| N5 |
M |
27y |
- |
Sarcoma |
Low back |
163.5cm² |
- |
281 min |
4 days |
| N6 |
M |
66y |
Smoking, SAH, previous AMI |
Melanoma |
R Thigh |
43.96cm² |
- |
280 min |
2 days |
| N7 |
F |
31y |
Obesity |
Sarcoma |
R leg |
38.46cm² |
- |
255 min |
1 day |
| N8 |
F |
50y |
Iron deficiency anemia, arrhythmia |
Sarcoma |
Low back |
32.97cm² |
- |
287 min |
2 days |
| N9 |
M |
62y |
Smoking, alcoholism |
Melanoma |
Back |
117.75cm² |
Dog ear |
318 min |
2 days |
Table 1 - Clinical characteristics of nine patients with malignant skin lesions treated with
resection and reconstruction with a Keystone flap.
The anesthetic-surgical time had an average of 289 minutes. This time includes the
anesthetic act, the duration of tumor resection and reconstruction by plastic surgery.
The mean hospital stay was 2.2 days. The reconstructions were completed with a single
surgery, except for one patient who needed to have the scar retouched due to “dog
ears,” which was later performed under local anesthesia. There were no postoperative
complications or flap losses. No patient was excluded from the sample.
DISCUSSION
The advantages of locoregional reconstruction have already been widely discussed in
the literature4. Short surgical time, stable vascularization and the satisfactory aesthetic result
of coverage using tissues adjacent to the defect are some of them2. The Keystone flap combines these benefits with its versatility, and can be used
in limb reconstruction2, trunk and face5, as demonstrated in our series (Figures 1, 2, 3).
Figure 1 - Defect of 38.46 cm2 in the right leg after sarcoma resection. A: Demarcation of the retail; B: Final aspect of the reconstruction; C: Late postoperative period.
Figure 1 - Defect of 38.46 cm2 in the right leg after sarcoma resection. A: Demarcation of the retail; B: Final aspect of the reconstruction; C: Late postoperative period.
Figure 2 - Defect of 4.35 cm2 in the left nasolabial sulcus after resection of infiltrative basal cell carcinoma.
A: Demarcation of the retail; B: Final aspect of the reconstruction; C: Late postoperative period.
Figure 2 - Defect of 4.35 cm2 in the left nasolabial sulcus after resection of infiltrative basal cell carcinoma.
A: Demarcation of the retail; B: Final aspect of the reconstruction; C: Late postoperative period.
Figure 3 - Defect of 32.97 cm2 in the lumbar region after sarcoma resection. A: Demarcation of the retail; B: Final aspect of the reconstruction; C: Late postoperative period.
Figure 3 - Defect of 32.97 cm2 in the lumbar region after sarcoma resection. A: Demarcation of the retail; B: Final aspect of the reconstruction; C: Late postoperative period.
Described by Behan et al. in 20031, the Keystone flap is a fasciocutaneous island flap3, 4. Its trapezoidal geometry, with a longer axis parallel to the defect, ensures the
recruitment of perforating vessels in the vicinity of the wound, making its vascularization
reliable. This design also allows for the advancement of tissue with little morbidity
to the donor area, so the closure in at least one of the extremities will be similar
to the V-Y6 flap. All donor areas were closed primarily, without major morbidities in this series.
The vascularization of this flap is proportional to the extension of the drawn skin
island, as long as the area of contact with the underlying fascia is maintained, through
which the perforating vessels emerge3, 4. This concept allows the manufacture of Keystone flaps of different sizes5. The rate
of complications described in the literature is 4%, mainly dehiscence and partial
necrosis7. In our series, the reconstructed area ranged from 4.35cm2 to 163.5cm2, without any complications with the vascularization of the flap.
The main limitation of the Keystone flap occurs when it is used in areas of inelastic
skin, which restricts its advancement and makes it impossible to close the donor area
without tension. Thus, it is not recommended to reconstruct the anterior face of the
leg, irradiated or extensively traumatized areas8. In addition, its reliability in mucosal coverage (intraoral and intranasal) has
not yet been studied3, 9. None of our patients met these restrictions.
CONCLUSION
The Keystone flap is a technically simple and reproducible option for covering wounds
of different sizes and in different locations. Due to its reliability, simple and
fast dissection, shortened hospital stay and low morbidity to the donor area, it should
be considered in reconstructing oncological wounds of different locations in patients
of all ages.
REFERENCES
1. Behan FC. The Keystone Design Perforator Island Flap in reconstructive surgery. ANZ
J Surg. 2003;73(3):112-20. DOI: 10.1046/j.1445-2197.2003.02638.x PMID: 12608972 DOI:
https://doi.org/10.1046/j.1445-2197.2003.02638.x
2. Rao AL, Janna RK. Keystone flap: versatile flap for reconstruction of limb defects.
J Clin Diagn Res. 2015;9(3):PC05-7. DOI: 10.7860/JCDR/2015/12595.5631 PMID: 25954659
DOI: https://doi.org/10.7860/JCDR/2015/12595.5631
3. Gómez OJ, Barón OI, Peñarredonda ML. Keystone Flap: Overcoming Paradigms. Plast Reconstr
Surg Glob Open. 2019;7(3):e2126. DOI: 10.1097/G0X.0000000000002126 PMID: 31044108
4. Mohan AT, Rammos CK, Akhavan AA, Martinez J, Wu PS, Moran SL, et al. Evolving Concepts
of Keystone Perforator Island Flaps (KPIF): Principles of Perforator Anatomy, Design
Modifications, and Extended Clinical Applications. Plast Reconstr Surg. 2016;137(6):1909-20.
DOI: 10.1097/PRS.0000000000002228 PMID: 26895582
5. Pelissier P, Gardet H, Pinsolle V, Santoul M, Behan FC. The keystone design perforator
island flap. Part II: clinical applications. J Plast Reconstr Aesthet Surg. 2007;60(8):888-91.
DOI: 10.1016/j. bjps.2007.03.023 PMID: 17493885 DOI: https://doi.org/10.1016/j.bjps.2007.03.023
6. Shayan R, Behan FC. Re: the “keystone concept’: time for some science. ANZ J Surg.
2013;83(7-8):499-500. DOI: 10.1111/ans.12303 PMID: 24049789 DOI: https://doi.org/10.1111/ans.12303
7. Khouri JS, Egeland BM, Daily SD, Harake MS, Kwon S, Neligan PC, et al. The keystone
island flap: use in large defects of the trunk and extremities in soft-tissue reconstruction.
Plast Reconstr Surg. 2011;127(3):1212-21. DOI: 10.1097/PRS.0b013e318205f36f PMID:
21364423 DOI: https://doi.org/10.1097/PRS.0b013e318205f36f
8. Pauchot J, Chambert J, Remache D, Elkhyat A, Jacquet E. Geometrical analysis of the
V-Y advancement flap applied to a keystone flap. J Plast Reconstr Aesthet Surg. 2012;65(8):1087-95.
DOI: 10.1016/j.bjps.2012.03.004 PMID: 22512938 DOI: https://doi.org/10.1016/j.bjps.2012.03.004
9. Chen HC. Precautions in using keystone flap. J Plast Reconstr Aesthet Surg. 2010;63(4):720.
DOI: 10.1016/j.bjps.2009.02.049 PMID: 19364682 DOI: https://doi.org/10.1016/j.bjps.2009.02.049
1. Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Serviço
de Cirurgia Plástica e Queimaduras, São Paulo, SP, Brazil.
2. Instituto do Câncer do Estado de São Paulo, Serviço de Cirurgia Plástica, São Paulo,
SP, Brazil.
Corresponding author: Renan Diego Américo Ribeiro Av. Dr. Enéas de Carvalho Aguiar, 255, 8º andar, São Paulo, SP, Brazil Zip Code:
05403-900 E-mail: renanamericor@gmail.com
Article received: April 30, 2021.
Article accepted: May 18, 2021.
Conflicts of interest: none.
Institution: Universidade de São Paulo, Faculdade de Medicina, Instituto do Câncer
do Estado de São Paulo e Hospital das Clínicas, São Paulo, SP, Brazil.
