Keywords
Free tissue flaps - Postoperative complication - Risk factors
INTRODUCTION
Reconstruction of the head and neck is challenging due to the variety of tissues whose
structural deficiencies must be corrected [1],[2], [3]. This is because the defects include a variety of structures: skin, mucosa, soft
tissue, and bone. In particular, the anatomy of the oral cavity is complicated, and
each structure plays a specific role in speech, swallowing, and facial expression.
In addition, defects in one specific functional unit can affect adjacent structures
[1],[2],[3]. Before reconstruction, a comprehensive assessment of the defect is required. Disease
status and tumor staging may also affect postoperative treatment and outcomes.
Reconstruction options for defects of the head and neck include primary closure, skin
graft, local flap, pedicled flap, and vascularized free flap transfer [1],[2],[3]. In the 1970 to 1980s, the local flap or pedicled flap was performed for coverage
of defects. However, although the pedicle flap was adequate for reconstruction, several
limitations, such as revision surgery for a bulky flap, limited arc of rotation, and
partial flap necrosis due to decreased blood flow of the flap distal portion, remained.
In addition, reconstruction using a pedicled flap is impossible in cases involving
an accompanying bone defect [3],[4],[5]. Recently, free flap surgery for surgical defects of the head and neck has gained
popularity as an advanced microvascular surgical technique [2],[3]. A literature review uncovered reports of successful performance of free flap transfer
for oncological surgical defects of the head and neck. However, free flap failure
remains a challenging problem [5]. The goals of this study are first, to determine whether the known risk factors
such as comorbidity, tobacco use, obesity, and radiation increase the complications
of free flap transfer and, second, to identify the incidence of complications in radial
forearm free flap (RFFF) and anterolateral thigh perforator flap (ALTPF).
METHODS
We conducted a retrospective review of medical records of patients with head and neck
cancer who underwent reconstruction with free flap transfer between May 1994 and May
2012 at our department of plastic and reconstructive surgery. A total of 42 patients
were considered. All free flap transfer procedures were performed immediately after
cancer ablation by a single senior surgeon. All of the medical records were reviewed
retrospectively for patients' characteristics, including body mass index (BMI), comorbidity,
history of smoking or alcohol use, tumor characteristics, preoperative radiotherapy,
type of reconstruction surgery, and complications. Complications were classified as
major complications and minor complications. The major complications were defined
as flap loss, arterial thrombosis, and venous thrombosis, and the minor complications
were defined as flap dehiscence, leakage, and fistula. A statistical analysis was
performed using a commercially available statistical software package, SPSS ver. 18.0
(SPSS Inc., Chicago, IL, USA). Fisher's exact test was used for the identification
of factors associated with free flap complications and for an evaluation of the differences
in the incidence of complications between RFFF and ALTPF. Statistical significance
was defined as P<0.05.
RESULTS
Between May 1994 and May 2012, 50 patients underwent reconstruction for defects of
the head and neck. Among them, 42 patients underwent free flap transfer for surgical
defects of the head and neck. All free flap transfer procedures were performed immediately
after cancer ablation. These patients included 36 men and 6 women, with a mean age
of 59.4 years. Three patients had diabetes, 6 patients had hypertension, and 30 patients
had a history of tobacco use. The average amount of smoking was 31 pack years, and
28 patients had a history of alcohol use. The mean BMI was 23 kg/m2. Two patients had a history of preoperative radiation therapy. The average operation
time was 301 minutes ([Table 1]). The most common primary tumor site was the tongue (31.8%), followed by the tonsils,
and the mouth floor. The most common tumor diagnosis was squamous cell carcinoma (76%)
([Table 2]). The most commonly used free flap transfer was RFFF (57%), followed by ALTPF (22%).
The other free flap transfers were the fibular free flap, latissimus dorsi myocutaneous
free flap, dorsalis pedis free flap, and jejunal free flap ([Table 3]). The most common recipient artery was the facial artery, in 36 cases, followed
by the superior thyroid artery, in 6 cases. Complications occurred in 10 patients
(24.8%), major complications occurred in 4 patients (9.5%), and minor complications
occurred in 6 patients (14%). In patients who developed major complications, one patient
had venous thrombosis, and three patients had partial flap loss. In patients who developed
minor complications, four patients had flap dehiscence, one patient had leakage, and
one patient had difficulty in swallowing. Complication rates for patients with hypertension
and diabetes were 16.7% and 33%, respectively. In the smoking patient group, complications
occurred in eight patients (26.7%). There was no occurrence of complication in patients
treated with preoperative radiation. In the obese patient group, complications occurred
in two patients (29%) ([Table 4]). In our study, according to the analysis using Fisher's exact test, the risk factors
of patients did not increase the complications of free flap transfer ([Table 5]). In the RFFF group, two patients (8.3%) developed partial necrosis and were managed
with secondary intention healing. In the ALTPF group, two patients (25%) developed
flap dehiscence and were managed with secondary intention healing. A comparison revealed
that the complication rate was higher in the ALTPF group than in the RFFF group, but
without statistical significance (25% vs. 8.3%, P>0.05) ([Table 5]).
Table 1.
Patient characteristics
|
Characteristic
|
Value
|
|
Sex (male:female)
|
36:6
|
|
Mean age (yr)
|
59.4
|
|
Smoking
|
30
|
|
Alcohol
|
28
|
|
Diabetic mellitus
|
3
|
|
Hypertension
|
6
|
|
Preoperative radiotherapy
|
2
|
|
Mean operation time (min)
|
301
|
|
Mean body mass index (kg/m2)
|
23
|
Table 2.
Tumor profile
|
Primary tumor site
|
|
Tumor cell type
|
|
|
Tongue
|
16
|
Squamous cell carcinoma
|
38
|
|
Tonsil
|
5
|
Adenoid cystic carcinoma
|
1
|
|
Mouth floor
|
4
|
Papillary carcinoma
|
1
|
|
Hypopharynx
|
3
|
Lymphoepithelial carcinoma
|
1
|
|
Buccal mucosa
|
3
|
Spindle cell carcinoma
|
1
|
|
Pyriform sinus
|
2
|
|
|
|
Larynx
|
2
|
|
|
|
Gingiva
|
2
|
|
|
|
Subglottis
|
1
|
|
|
|
Soft palate
|
1
|
|
|
|
Mandible
|
1
|
|
|
|
Lower lip
|
1
|
|
|
|
Esophagus
|
1
|
|
|
|
Total
|
42
|
Total
|
42
|
Table 3.
Type of flap
|
Type of flap
|
No. (%)
|
|
Radial forearm free flap
|
24 (57.1)
|
|
Anterior lateral thigh perforator flap
|
8 (19.0)
|
|
Fibular free flap
|
6 (14.3)
|
|
Latissimus dorsi myocutaneous free flap
|
2 (4.8)
|
|
Dorsalis pedis free flap
|
1 (2.4)
|
|
Jejunal free flap
|
1 (2.4)
|
|
Total
|
42 (100)
|
Table 4.
Incidence of complications associated with risk factor
|
Risk factor
|
With complications
|
Total
|
|
Values are presented as number (%).
|
|
Hypertension
|
1 (16.7)
|
6
|
|
Diabetic mellitus
|
1 (33.3)
|
3
|
|
Smoking
|
8 (26.7)
|
30
|
|
Preoperative radiotherapy
|
0 (0)
|
2
|
|
Obesity
|
2 (29)
|
7
|
Table 5.
Complication rate associated with risk factors and flap type
|
Complication
|
Non-complication
|
P-valuea)
|
|
Values are presented as number (%).
HTN, hypertension; DM, diabetic mellitus; RT, radiation therapy; RFFF, radial forearm
free flap; ALTPF, anterolateral thigh perforator flap.
a) Fisher’s exact test.
|
|
HTN
|
1 (16.7)
|
5 (83.3)
|
1.000
|
|
Non-HTN
|
8 (22.0)
|
28 (78.0)
|
|
|
DM
|
1 (33.3)
|
2 (66.7)
|
1.000
|
|
Non-DM
|
5 (12.8)
|
34 (87.2)
|
|
|
Smoking
|
8 (26.7)
|
22 (73.3)
|
0.696
|
|
Non-smoking
|
2 (16.7)
|
10 (83.3)
|
|
|
Preoperative RT
|
0 (0)
|
2 (100)
|
1.000
|
|
Non-preoperative RT
|
11 (27.5)
|
29 (72.5)
|
|
|
Obesity
|
2 (29)
|
5 (71.0)
|
1.000
|
|
Non-obesity
|
8 (27.6)
|
21 (72.4)
|
|
|
RFFF
|
2 (8.3)
|
22 (91.7)
|
0.148
|
|
ALTPF
|
2 (25)
|
6 (75)
|
|
DISCUSSION
A total of 42 free flap transfers for reconstruction of surgical defects of the head
and neck were considered in our study. Despite the small size of our study sample,
free flap failure did not occur. All of the surgical procedures were performed by
a single senior surgeon over a long period; therefore, our surgery outcomes showed
consistency by avoiding the influence of differences in the technical skill of multiple
centers and/or multiple surgeons. In addition, to avoid inadvertent anteroposterior
wall suture in microvascular anastomosis, the surgeon performed vascular anastomosis
using a modified Harashina procedure and achieved leak-proof and reliable anastomosis
[6].
In our study, an analysis using Fisher's exact test revealed that the risk factors
of patients did not increase the incidence of complications. Similar to our report,
multiple centers have previously reported that risk factors of microvascular surgery
did not increase the rate of complications. Bozikov and Arnez [7] reported that only diabetic patients had a higher incidence of free flap complication,
although this fact did not achieve significance in the statistical analysis. Bianchi
et al. [8] reported a higher frequency of complications in patients older than 70 years, diabetic
patients, and patients treated with preoperative radiation, although the differences
were not statistically significant. Choi et al. [9] reported obesity as the only independent factor for the development of complications,
while the number of risk factors of the patient showed an association with increased
risk. In our study, two patients received treatment with preoperative radiation therapy.
Among them, there was no occurrence of complications. However, although irradiated
tissues were known to be risk factors for wound healing and microvascular surgery,
the influence of irradiated tissue on free flap transfer has been controversial [10]. Mulholland et al. [11] and Singh et al. [12] reported that prior radiation therapy did not have a negative impact on microvascular
surgery. Chao et al. [13] reported that perioperative recipient-site complications occurred at a rate similar
to the rate experienced by non-irradiated patients and free flap losses were not increased
despite potential damage to recipient vessels with neoadjuvant radiation therapy.
In our study, RFFF and ALTPF flaps were employed most often. In the RFFF group, complications
occurred in 8.3% of the patients, whereas in the ALTPF group, complications occurred
in 25% of the patients. However, an analysis using Fisher's exact test revealed that
a larger number of complications occurred in the ALTPF group than in the RFFF group,
although the difference was not statistically significant ([Table 5]). A review of the literature showed that our results are comparable with the results
reported by others: Baek et al. [14] reported that complications occurred in 6.7% of the patients in the ALTPF group
that they considered, and Smith et al. [15] reported the occurrence of complications in 18.6% of the patients in the RFFF group
of their study. Similar to our results, Baek et al. [14] and Smith et al. [15] reported that most complications were venous thrombosis and congestion. Bianchi
et al. [16] and Kesting et al. [17] reported several advantages of the anterolateral thigh flap for head and neck defects,
including versatility, short harvesting time, and donor site morbidity. However, Kesting
et al. [17] reported that intra-operative arterial spasms occurred more often in the case of
the ALT free flap than in the case of RFFF and that venous congestion was the most
frequent complication in the case of the RFFF. The larger diameter of veins accompanying
the descending branch may be a possible reason for fewer venous complications and
higher salvage rates in the case of the ALT flap than in the case of RFFF [17]. Bianchi et al. [16] reported that the ALT flap is a good donor but is not suitable for small defect
areas or in cases that require a pliable or thin flap. In addition, they reported
several disadvantages: in obese patients, the flap could be bulky, and in a hairy
patient, hair could grow in unwanted areas. RFFF has the advantage of short operative
time, but has several drawbacks, such as a visible scar on the forearm and a sacrifice
of a major vessel of the hand, which could be a burden for both the surgeon and the
patient. ALTPF for most head and neck reconstructions, particularly in the intraoral
cavity, hypopharynx, and oropharynx, has been performed by a senior surgeon since
2007. Nevertheless, as ALTPF is similar to RFFF with respect to the characteristics
of thinness and pliability, ALTPF is a little more difficult for a novice surgeon
to perform because of a longer operative time and the requirement of surgical skill
with a steep competency learning curve. However, vessel anatomy has already been investigated
in several previous cadaver and radiological studies, and a preoperative perforator
could be identified using computed tomographic angiography. These useful tools could
be helpful to young surgeons while performing ALTPF. Therefore, ALTPF is a good alternative
to RFFF in patients in whom RFFF is contraindicated or who do not want to undergo
RFFF.
Our study has several limitations. First, the sample size of our study was small compared
to that of the other studies on this topic. Therefore, we used Fisher's exact test
for the identification of factors associated with free flap complications. Second,
we could not evaluate the outcomes in terms of functional aspects and patients satisfaction.
Meanwhile, our study has several advantages: First, all surgical procedures were performed
by a single surgeon over a long period of time; therefore, our surgical outcomes showed
consistency by avoiding the influence of multiple centers and/or multiple surgeons.
Second, we compared the complication rates of RFFF and ALTPF. A recent study focused
mainly on the versatility and outcomes of ALT flap surgery for the reconstruction
of the head and neck. However, we evaluated only ALTPF versus RFFF, which is a thin
and pliable flap.
In our study, risk factors did not influence the outcomes of free flap transfer, which
was in agreement with previous studies. From the results of our study, we were able
to conclude that the surgeon's expertise in performing microvascular surgical techniques
is an important factor for the achievement of a good result of free flap transfer.
Therefore, the patient's risk factors no longer be considered a negative factor for
a free flap transfer. In addition, ALTPF is a good alternative to RFFF in patients
in whom it is contraindicated or who do not want to undergo RFFF.
