Keywords
incisional negative pressure therapy - anterolateral thigh flap - complications -
free flap - microsurgery - donor site
The free anterolateral thigh flap (ALT) is widely recognized as a workhorse flap in
reconstructive microsurgery.[1] Primary closure of the donor-site usually gives an adequate cosmetic result with
minimal morbidity. However, harvest of larger flaps is increasingly related to donor-site
complications or may require use of split thickness skin grafting, producing significant
scarring ([Fig. 1]).[2] When primary closure is done under excessive tension, it can lead to numerous complications
including wound dehiscence, skin necrosis, seroma, and infection ([Fig. 2]). Several experimental reports show that incisional negative pressure therapy (INPT)
improves the microcirculation and also decrease tension across the suture.[3] Furthermore, there is clinical evidence, which suggests that INPT may reduce the
incidence of complications in wounds closed under tension, like mastectomy flaps or
the donor-site of the superficial circumflex iliac artery perforator flap.[4]
[5]
Fig. 1 Anterolateral thigh flap donor-site appearance after skin grafting. (A) Intraoperative view with meshed skin graft; (B) Six months postoperative result; (C) Intraoperative view with fenestrated skin graft; (D) Six months postoperative result.
Fig. 2 Anterolateral thigh free flap donor-site complications after primary closure: (A) Skin necrosis and dehiscence; (B) Wound dehiscence.
The objective of this study is to evaluate if the use of INPT reduces the incidence
of complications after primary closure of the ALT flap donor-site.
Methods
After institutional review board approval, we conducted a retrospective cohort study
from a prospective maintained database of patients operated between 2009 and 2016,
both groups were intervened in the same period of time. Patients who underwent upper
and lower limb reconstruction using an ALT free flap with primary closure of the donor-site
were included. Patients who required skin grafting of the donor-site were excluded
from this study. All participants correspond to a captive population, which is beneficiary
of a national work-related injury insurance that provides life-long medical assistance
and economic compensation for injuries caused by work-related accidents or occupational
illnesses.
Patient demographic data and intraoperative details regarding type and size of the
flaps were collected for analysis. Postoperative donor-site complications were prospectively
recorded. During hospital stay, wounds were inspected on a daily basis. After discharge
patient follow-up included a weekly visit for the first month, then monthly for the
first 6 months and then every 3 months for at least 1 year.
Two groups were defined: primary closure with traditional dressings (control group),
and primary closure of the donor-site and INPT (study group). In general, the control
group was the historical group, the first patients intervened in the series, prior
to the use of the INPT. Both incision care methods were performed over the entire
study period.
For the performance of an ALT, patients with a BMI (body mass index) > 25 were excluded,
that is, no patient in the series was obese or overweight.
Surgical Technique and Incisional Negative Pressure Therapy
Primary closure of the ALT donor-site was performed in two or three layers, depending
on the feasibility to close the deep fascia, using 1-0 Vicryl (Ethicon; Sommerville,
New Jersey) for the fascial layer, 1-0 Vicryl for the subdermal plane, and an intradermal
suture of 3-0 Vicryl (Stratafix, Johnson & Johnson). A suction drain was left in place
in all the cases. In the control group, wounds were covered with gauze and a paper
tape dressing (Micropore, 3 M). In the study group, INPT was installed immediately
after wound closure (Renassys; Smith and Nephew, London). The polyurethane foam of
the negative pressure therapy device was placed in direct contact with the wound.
Adjacent skin to the wound edges was protected from contact with the foam using a
cutaneous protective film (Cavilon) and a layer of adhesive drape. Therapy was set
at a pressure of (−)120 mm Hg in continuous mode for 7 days, after which it was changed
to a traditional dressing. INPT installation procedure is detailed in [Video 1].
Video 1 Intraoperative INPT installation procedure.
Statistical Analysis
Data were analyzed using the SPSS software version 21.0 using nonparametric tests.
Values were expressed in medians (Q1–Q3) and results between both groups were compared
using the Fisher test and U Mann–Whitney test. Logistic regression analysis was employed to determine prognostic
factors and p < 0.05 was considered statistically significant. All patients gave informed consent
to participate in this study.
Results
During the study period 58 free ALT flaps with primary closure were performed in 58
patients (study group n = 28; control group n = 30). All patients were male, with a median age of 42 years (range: 26–57 years).
Median follow-up was 19 months (range: 3–78 months). There were no significant differences
in age, flap size, or comorbidities between both groups (p > 0.05) ([Table 1]).
Table 1
Characteristics of patients treated with an ALT free flap and primary closure of the
donor-site (n = 58)
|
Control group (n = 30) (Q1–Q3)
|
INPT
(n = 28) (Q1–Q3)
|
p-Value
|
|
Age (y)
|
42.5 (33–53)
|
38 (28–56)
|
NS
|
|
Width (cm)
|
8 (7–10)
|
9 (8–10)
|
NS
|
|
Length (cm)
|
21.5 (18–27)
|
25 (21.5–30)
|
NS
|
|
Area (cm2)
|
155.4
(132–224)
|
210.5
(146–238)
|
NS
|
|
Smoking (n; %)
|
3 (10)
|
4 (14)
|
NS
|
|
Diabetes (n; %)
|
1 (3)
|
0 (0)
|
NS
|
Abbreviations: ALT, anterolateral thigh; INPT, incisional negative pressure therapy;
NS, nonsignificant.
The global and specific complications rates among both groups are described in [Table 2]. The complications were distributed over time in a similar manner throughout the
study period. The global complication rate was 36.6% (n = 11) in the traditional dressing group and 7.14% (n = 2) in the INPT group (p < 0.007; [Fig. 3]). There was a significant difference in the incidence of wound dehiscence (p < 0.028) and skin necrosis (p < 0.039) between both groups. We observed a significant risk reduction for global
complications (odds ratio [OR] = 0.13; 95 CI, 0.03–0.58), dehiscence (OR = 0.17; 95
CI, 0.04–0.82) and skin necrosis (OR = 0.35; 95 CI, 0.08–0.97), in this cohort.
Fig. 3 Global complication rate for each group.
Table 2
Global and specific complication rates for each group (n = 58)
|
Control group
(n = 30) (n; %)
|
INPT
(n = 28) (n; %)
|
p-Value
|
|
Global complications
|
11 (37)
|
2 (7)
|
0.007
|
|
Wound dehiscence
|
9 (30)
|
2 (7)
|
0.028
|
|
Skin necrosis
|
6 (20)
|
2 (7)
|
0.039
|
|
Wound infection
|
2 (7)
|
1 (4)
|
0.32
|
When stratifying patients according to flap width, no complications occurred if flap
width was less than 8 cm. Conversely in flaps, wider than 8 cm, the incidence of complications
increased in both groups being significantly lower in the study group (p < 0.048, [Fig. 4]). Multivariate logistic regression analysis showed that among all the variables
studied, only the use of INPT (OR = 0.21; CI [0.06–0.63], p < 0.008) and flap width < 8 cm had a significant relation with decreased complication
rates (OR = 0.54; CI [0.03–0.86], p < 0.003) ([Fig. 5]).
Fig. 4 Global complication rate stratified by flap width.
Fig. 5 Scar appearance after use of INPT. (A) ALT flap harvest (34 × 11 cm). (B) Incisional negative pressure therapy. (C) Three months postoperative result. ALT, anterolateral thigh; INPT, incisional negative
pressure therapy.
Discussion
The ALT flap has an established role in the reconstruction of multiple anatomical
areas. This flap has considerable advantages that explain its increasing popularity
as a workhorse flap, such as an adequate pedicle length, versatility in its design,
inclusion of different components if needed and also allowing to work in two teams,
among many others.[1]
[6]
[7]
However, complications related to the donor-site may occur, especially when harvesting
wide flaps. The ALT donor-site complication rates range from 11 to 21.3%, with wound
dehiscence being the most common complication.[2]
[8]
[9]
[10] In a recent systematic review about donor-site complications following free flap,
the most frequently performed flap was the ALT flap, and the most frequent complications
were dehiscence (3.8%), seroma (2%), and hematoma (0.9%), being important the early
treatment of the donor-site to avoid them.[11] Subsequently, donor-site related morbidity may increase the length of hospital stay
and related costs.[12]
With harvesting techniques such as Super-Thin and Suprafascial ALT flaps is possible
to achieve a potential decrease in complications in the donor-site, such as muscle
hernia; however, does not allow a greater number of cases with primary closure, reaching
only 22.2% of primary closure in some of the studies, requiring grafting in the another
cases.[13]
[14]
The use of negative pressure therapy has been recently applied as a preventive therapy
in high-risk surgical wounds closed under tension, under the concept of incisional
negative pressure therapy (INTP). This therapy may have several benefits, which are
related to the following possible mechanisms: (1) a tension decrease across the wound
edges in both the skin and the underlying tissue; (2) a compressive effect, decreasing
the dead space and thus the formation of fluid collections or seromas; (3) reduction
of edema and an improvement in local blood supply and isolation of the wound decreasing
the chances of infection.[3]
[15]
[16]
[17]
[18] All of the above may contribute to a decrease in surgical-site complications of
high-risk wounds.
The use of INPT has been favorably described as a preventive treatment for donor-sites
of other flaps, such as latissimus dorsi muscle, where the main concern is seroma
formation, showing a decrease in the seroma incidence from 70 to 15% (OR = 0.07; relative
risk (RR) = 0.24).[19] It has also been used on the donor-site of perforator flaps, such as the superficial
circumflex iliac artery perforator flap (SCIP), where seroma and hematoma are the
causative elements in wound complications. INPT was effective reducing the amount
of fluid collected by suction drains, allowing its earlier removal.[5]
To the best of our knowledge, this study is the first to analyze the use of INPT in
the ALT flap donor-site. In this cohort, we obtained an 80% reduction of donor-site
complications when compared with standard dressings, significantly decreasing the
incidence of wound dehiscence and and skin necrosis, especially for wider flaps.
We believe that operative time is not increased, since INPT is installed simultaneously
while the rest of the team is completing the microsurgical procedure. The cost of
the device in our center is approximately U.S.$ 120 for each patient. Although, a
cost analysis was not performed, it is expected that this will be beneficial, given
the decrease in the complications rate, which should be associated with a reduction
in hospital stay and reoperations.[15]
[20] Furthermore, reducing postoperative complications would decrease the emotional burden
on the patient, thus improving their quality of life.[21]
There are some limitations in this study that should be addressed. This is a retrospective
cohort study and as such there was no randomized allocation of the treatment. Additionally,
neither patients nor physicians are blinded to the intervention. Despite these facts,
we highlight that this cohort belongs to a captive population, in which lifelong treatment
is guaranteed. Consequently, patients usually have a complete and extended follow-up,
in which unfavorable outcomes are precisely registered to estimate individual monetary
compensation after every work-related injury.
Conclusion
In this cohort, the use of INPT reduced the morbidity after primary closure of the
ALT free flap donor-site. A significant reduction in wound dehiscence and skin necrosis
was observed. This therapy might prove to be a useful adjunct to prevent donor-site
complications, especially after harvest of wide flaps.
