Abstract
Background
The use of a free flap has become a mainstay of reconstruction following the ablative surgery in head and neck. The success rates are about 90%, however, several factors have been described to have an adverse effect on free flap survival.
Methods
We have performed a retrospective analysis of the treatment outcome of 93 microvascular flaps and evaluated the factors influencing the risk of flap loss including patients’ age, body mass index, smoking, general medical history and previous oncological treatment.
Results
Out of 93 flaps the total necrosis have been observed in 15 flaps with gradual improvement in the consecutive years. In individual analysis the patients age, BMI, and comorbidities did not reveal any significant relation. The history of any previous oncological treatment represented a significant adverse factor of success rate ( p = 0.035), and was even more significant when patients experienced all treatment modalities prior to the reconstructive procedure ( p = 0.009). Multivariate logistic regression model indicated that only surgery ( p = 0.0008), chemotherapy ( p = 0.02), cardiovascular diseases ( p = 0.05) and patient’s age ( p = 0.02) represented significant factors impairing the success rate.
Conclusion
Incorporating multivariate analysis represents important statistical approach for better prediction of free flaps survival in head and neck reconstructive surgery. Incorporation of additional collective information could provide more precise approach in the risk of the flap loss assessment.
1
Introduction
In the last three decades the use of free tissue transfer from distant anatomic locations has become a mainstay in reconstruction of the large and complex deficits in head and neck. It enables reconstructing defects otherwise impossible with locoregional flaps and facilitates aggressive and radical resection of tumors, ultimately improving the survival.
Increasing surgical expertise and the evidence that the free flaps provide better success and functional outcome than locoregional flaps have shifted the paradigm in reconstructive techniques . A great variety of available flaps allow establishing a balance between the functional outcome providing good speech, mastication and swallowing and the esthetic appearance which has a great impact on the quality of life.
There is a variety of flaps available, however, the anterolateral thigh flap (ALT), free radioforearm flap and fibular composite flap for mandibular reconstruction are among the most frequently chosen for the reconstructions in the head and neck .
Nevertheless, most authors present rather high success rates of the free flap reconstructive techniques ranging between 91 and 99% . There is always a potential risk for a failure, which may have devastating consequences and adverse impact on the treatment outcome . Although potential complications can always occur, there has been a number of factors reported to significantly increase the risk of failure.
These factors can be divided into patient related, such as age, comorbidities, and the initial treatment history, and more technical, dependent on the surgeon, related to the surgical technique, but also the proper selection of the reconstructive technique and customizing the flap .
The aim of this study is to investigate the incidence and etiology of the flap losses in our patients and to determine the risk factors that may have an adverse impact on success rate.
2
Methods
A retrospective review was performed of all free flaps for head and neck reconstruction from January 2011 to March 2015 after Institutional Review Board approval. Medical records of all patients were reviewed for demographics, comorbidities, treatment characteristics, including neo-adjuvant and adjuvant therapy, and post-operative complications.
2.1
Patients
Ninety-one patients diagnosed with HNSCC were enrolled into the study after obtaining written consent. Altogether 93 free flap reconstructions following the ablative surgery in head and neck region have been performed.
The location of the defect resulting from tumor resection were within oral cavity (n = 66), the lip (n = 7), mandible (n = 3), the skin of the head and the face (n = 13) and hypopharynx (n = 1) ( Table 1 ).
| Defect location | Type of flap | |||
|---|---|---|---|---|
| Radial forearm | Anterolateral thigh | Fibula | No. of flaps | |
| Oral cavity | 38 | 26 | – | 64 |
| Lip | 2 | 5 | 7 | |
| Mandible | 0 | 2 | 6 | 8 |
| Scalp and skin of the face | 2 | 11 | – | 13 |
| Pharyngoesophagus | 1 | 0 | – | 1 |
| Total | 43 | 44 | 6 | 93 |
The mean length of the hospital stay after free flap surgery was 15 ± 3 days.
2.2
Flap monitoring
In our department the flap is examined by visual inspection and palpation every 1 h for the first 24 h, and every 4 h for the remaining time of hospitalization. During a routine flap inspection, the following parameters are being checked: temperature, turgor, color and capillary refill. In case the flap viability is doubtful, a surgeon experienced in micro vascular techniques inspects the flap and performs the percutaneous Doppler examination and a pin-prick test if necessary.
2.3
Statistical analysis
Statistical analysis was performed on SAS (SAS University Edition, SAS Institute Inc., Cary, NC, USA). Fisher exact test was used to analyze the effect of individual predictors on reconstruction surgery outcome (age, BMI, smoking, diabetes, cardiovascular diseases, alcohol withdrawal syndrome, COPD, other comorbidities, surgery, chemotherapy and radiotherapy). Univariate and multivariate logistic regression analysis was performed to estimate the odds ratio. For the analysis of the treatment effect it was considered the effect of each isolated individual treatment (surgery, chemotherapy and radiotherapy) and its possible combinations. For the multivariate model, a stepwise logistic regression procedure was performed to identify independent variables that contributed to the most for predicting flap loss. A backward selection technique was used to eliminate covariates that did not contribute to the model. A significance level of 0.3 or above was used to remove covariates from the multivariable model, and a value of 0.35 or less was used to include variables. A p value ≤ 0.05 was considered statistically significant.
2
Methods
A retrospective review was performed of all free flaps for head and neck reconstruction from January 2011 to March 2015 after Institutional Review Board approval. Medical records of all patients were reviewed for demographics, comorbidities, treatment characteristics, including neo-adjuvant and adjuvant therapy, and post-operative complications.
2.1
Patients
Ninety-one patients diagnosed with HNSCC were enrolled into the study after obtaining written consent. Altogether 93 free flap reconstructions following the ablative surgery in head and neck region have been performed.
The location of the defect resulting from tumor resection were within oral cavity (n = 66), the lip (n = 7), mandible (n = 3), the skin of the head and the face (n = 13) and hypopharynx (n = 1) ( Table 1 ).
| Defect location | Type of flap | |||
|---|---|---|---|---|
| Radial forearm | Anterolateral thigh | Fibula | No. of flaps | |
| Oral cavity | 38 | 26 | – | 64 |
| Lip | 2 | 5 | 7 | |
| Mandible | 0 | 2 | 6 | 8 |
| Scalp and skin of the face | 2 | 11 | – | 13 |
| Pharyngoesophagus | 1 | 0 | – | 1 |
| Total | 43 | 44 | 6 | 93 |
The mean length of the hospital stay after free flap surgery was 15 ± 3 days.
2.2
Flap monitoring
In our department the flap is examined by visual inspection and palpation every 1 h for the first 24 h, and every 4 h for the remaining time of hospitalization. During a routine flap inspection, the following parameters are being checked: temperature, turgor, color and capillary refill. In case the flap viability is doubtful, a surgeon experienced in micro vascular techniques inspects the flap and performs the percutaneous Doppler examination and a pin-prick test if necessary.
2.3
Statistical analysis
Statistical analysis was performed on SAS (SAS University Edition, SAS Institute Inc., Cary, NC, USA). Fisher exact test was used to analyze the effect of individual predictors on reconstruction surgery outcome (age, BMI, smoking, diabetes, cardiovascular diseases, alcohol withdrawal syndrome, COPD, other comorbidities, surgery, chemotherapy and radiotherapy). Univariate and multivariate logistic regression analysis was performed to estimate the odds ratio. For the analysis of the treatment effect it was considered the effect of each isolated individual treatment (surgery, chemotherapy and radiotherapy) and its possible combinations. For the multivariate model, a stepwise logistic regression procedure was performed to identify independent variables that contributed to the most for predicting flap loss. A backward selection technique was used to eliminate covariates that did not contribute to the model. A significance level of 0.3 or above was used to remove covariates from the multivariable model, and a value of 0.35 or less was used to include variables. A p value ≤ 0.05 was considered statistically significant.
3
Results
3.1
Outcome of reconstruction
In the present study of 93 flaps, 43 were radial forearm flaps, 44 anterolateral thigh free flaps and 6 fibula osteocutaneus flaps ( Table 1 ). In the analyzed group, microvascular complications were observed in 21 flaps. In 11 flaps the complications have been observed within first 72 h and in 10 remaining flaps the necrosis developed later than 4 days postoperatively. In one case flap loss has been observed after 150 days as a result of radionecrosis. Total necrosis of the flap was identified in 15 cases giving a total success rate of 83.88%. In 6 cases the mechanical compression of the pedicle has been identified as a reason of the flap failure. In 3 patients the pedicle was compressed by the hematoma in the neck. Excessively tight dressing and the neck hyper flexion was suspected as a cause in 2 other patients suffering from alcohol withdrawal syndrome. The tracheostomy ties were the most probable cause for pedicle compression in 1 case. The infection of the neck with the presence of fistula resulted in flap failure in 2 individuals and has developed later than a week post operatively. In 6 cases, despite the good flap condition for the first 72 h, the total necrosis was eventually reported. The reason of the flap loss was not identified in those cases, while there was a presence of thrombosis in both the artery and the vein.
The revision of the microvascular anastomosis was performed only in 12 cases where complication occurred in 24–72 h, and 6 flaps (54.5%) have been successfully salvaged. In other cases, the flap was removed and the alternative reconstructive modality was carried out. In 3 cases the surgical defect was reconstructed with another free flap and in every case alternative donor vessels were identified. The local flap was used in 3 cases and pectoralis major flap in 4 cases. In 5 patients the defect resulting from the removal of the compromised flap allowed the primary closure. In subsequent reconstructions no complications were recorded ( Table 2 ).
| Reconstruction | Initial | Subsequent |
|---|---|---|
| Radial forearm fasciocutaneus | 7 | 1 |
| Anterolateral thigh | 7 | 2 |
| Fibula osteocutaneus | 1 | – |
| Pectoralis major pedicled | – | 4 |
| Local/locoregional flap | – | 3 |
| Primary closure | – | 5 |
3.2
Surgeon dependent factors-learning curve
The reconstructive procedures based on microvascular techniques have been introduced in our institution in 2011, and since then, all procedures have been performed by the same surgical team. The beginning success rate was 75% with significant improvement to 81.38%, 83.33%, 92.86% and 92.86% in consecutive years, respectively ( Fig. 1 ).
3.3
Patient dependent factors
The comprehensive analysis of the patient’s medical history have been performed in order to identify the factors that may have the adverse effect on the success rate of the surgery.
Patient’s age, history of smoking, BMI, comorbidities and history of the previous treatment have been recorded and analyzed ( Table 3 ).
