Comparison of the hospitalization period after microvascular reconstruction flap in trismus patients: free anterolateral thigh flap versus free forearm flap

To address the research purpose, the investigators evaluated surgical outcome in a group of OSCC patients who underwent surgical resection and reconstruction with free flap. The study population comprised all patients presenting for evaluation and management of flap recovery during the period between the date of operation with the two flaps and the date of full flap healing.

Patients with treated primary OSCC underwent surgical resection between 2010 and 2016 in the same medical center hospital. For inclusion in the study sample, the study inclusion criteria were as follows: (1) previously untreated oral cancer, (2) histologically proven squamous cell carcinoma, (3) reconstruction with the ALT or RFFF flap, (4) therapeutic resection and selective neck lymphatic dissection with or without adjuvant postoperative therapy, and (5) a history of betel nut exposure with the trismus problem of maximum inter-incisor distances (IIDs) < 5 mm. The exclusion criteria were as follows: (1) unavailable data regarding IIDs at initial recording and postoperative recording, (2) final pathological diagnosis of T3 or T4 lesion due to the inability to use RFFF, (3) history of treatment for other cancers, (4) contraindication for curative surgery, (5) distant metastasis, and (6) history of oral submucosa fibrosis and treatment via free flap.

Finally, we included 49 trismus patients, and IID was measured as the maximal distance between the edges of the incisors of the mandible and the maxilla at three points in time: before operation (initial IID), post operation 2 weeks, and post operation 6 months. The IID was expressed in millimeter, similar to the report by Dijsktra et al. [15]. Due to the trismus problem, tumor excisions were performed using mandibulectomy or the pull-through technique with the lymphatic nodal specimen. All patients were followed and registered in an institutional database corrected and updated with the patients’ most recent treatment condition. The follow-up duration was at least 2 years or until death by the endpoint of December 2017. The Ethics Committee of the Tri-Service General Hospital (Taipei, Taiwan) approved the study (Institutional Review Board protocol no: 2-107-05-021). Given the retrospective nature of the study and the use of anonymized patient data, requirements for informed consent were waived.

Surgical reconstruction was performed by the same group of experienced plastic surgeons; patients were transferred to the intensive care unit for flap monitoring after reconstruction, and then sent to the general ward for wound healing. After appropriate healing and restoration of basic function, the patients were discharged. These patients were candidates for reconstruction with RFFF or ALT flap independent of surgeon and patients’ preference. The reason for selection of the ALT flap was concern regarding the fine motor activity of the hand; the reason for selection of the RFFF flap was concern regarding the operative time. The donor site evaluation was performed before surgery using Doppler ultrasonography. Specifically, the radial forearm flap was surveyed using Doppler ultrasonography, and the Allen test was performed and the radial side was pressed to guarantee re-perfusion from the ulnar side to a healthy color within 15 s. The RFFF was dissected and reconstructed on the same operative day, and the skin graft from the anterolateral thigh region was used to cover the RFFF site. This study did not detect any complication or prolonged healing period in the skin graft. In contrast, the ALT flap was checked using Doppler ultrasonography with or without computed tomography angiography. After mapping and draping the perforators to penetrate the fascia in the medial or proximal one-third of the anterolateral thigh region, the ALT was dissected at the time of the therapeutic operation. After reconstruction, these patients were transferred to the flap care intensive critical unit, and the flaps were monitored according to physical appearance and handheld Doppler ultrasound probe monitoring. Surgical parameters were registered as multiple factors, such as flap reconstructive time, postoperative recovery days, patient survival, complications of flap healing, and data on serum white blood cell (WBC) count, were collected and analyzed to assess flap healing.

The important surgical parameters are primarily based on the flap recovery healing period and the incidence of postoperative complications. The primary comparison of recovery between the two flaps was the measurement of flap healing from the date of the operation to the date of discharge. Postoperative complications were also compared between the two flaps; fortunately, these patients experienced no major complications, such as flap crisis, thrombosis, or failure, similar to the success rate in general flap operation. However, minor complications at the surgical site were observed.

The other factors related to the flap recovery healing time were inter-incisor distances, flap operative time, WBC count, and the onset of leukocytosis; these were analyzed as indicators of flap recovery. The flap operative time is measured from the initiation of the plastic specialist’s procedure until full flap reconstruction. The WBC count referred to the number of white blood cells via blood exam. Normal WBC count in peripheral blood is within the reference range of 4300 to 10,800 WBC/mm³ [16]. Leukocytosis was defined as WBC count above the normal range in the blood. The chi-squared test was used to compare categorical variables of patient demographic profiles between the ALT and RFFF groups. The Kaplan-Meier method was used to calculate overall survival (OS), measured from the day of therapeutic surgery to the date of death or the last follow-up; this was used to evaluate survival rate stratified according to different flap reconstructions. Statistical analysis was performed by using commercially available statistical software (SPSS version 20.0, IBM Corporation, Armonk, NY, USA); p < 0.05 was considered statistically significant.

Demographic information of the entire patient cohort, including age, sex, population, histopathology T stage, N stage, treatment modality, and anatomical site, are presented in Table 1. Final histopathological results revealed 22 (44.9%) patients with pT1 status and 27 (55.1%) with pT2 status. RFFF reconstructions were performed in approximately 23 cases and ALT reconstructions were performed in 26. The reconstructed flap was divided into two sub-groups for comparative analyses with characteristic features (Table 2). Accordingly, no significant relationships were found between the reconstructed free flaps and sex, age, tumor stage, pathological T or N status, smoking habits, and initial inter-incisor distances via chi-square analysis. The follow-up period indicated no significant differences via independent t test. The mean (± standard deviation [SD]) follow-up period for all patients was 36.6 ± 19.6 months. The mean OS period was 57.8 ± 4.0 months among the 49 patients. According to Kaplan-Meier analysis, OS at 1, 3, and 5 years was 89.4%, 71.5%, and 67.7%, respectively. There was no statistically significant difference in OS between the two reconstruction groups.

Reconstructed flaps were divided into two sub-groups for comparative analyses (Table 3) and the flap indicators were subsequently divided for recovery analysis. The mean number of hospitalization days for recovery from the flap surgery day to the day flap stability that was sufficient for discharge was 22.9 ± 7.2 in the ALT group and 27.8 ± 7.0 in the RFFF group, a difference that was statistically significant (p = 0.012). The mean WBC counts in the ALT and RFFF groups were 7428.9 ± 2454.9 WBC/mm³ and 9438.7 ± 3151.3 WBC/mm³, respectively, a difference that was statistically significant (p = 0.016). Two-week maximum IIDs were measured: 16.1 ± 0.8 mm in the ALT group and 7.0 ± 0.6 mm in the RFFF group. The ALT group had significantly wider mouth opening ability than the RFFF group. After 6 months of rehabilitation, these two groups exhibited similar IIDs. In flap operative time, the ALT operation was approximately 619.9 ± 250.1 min, while the RFFF was approximately 390.5 ± 108.9 min.

In analysis of the relationship with the hospitalization period (Table 4), we found that the 2-week postoperative IIDs in the ALT group were much larger than those of the RFFF group, and there was minimal correlation with the number of hospitalization days (r = − 0.327; p = 0.022). Additionally, there was no relation of other factors with the hospitalization period, including WBC count, initial IID, postoperative 6 months IID, patient sex, and flap operative time.

There were some minor complications in the two groups, while the success rate for the two groups was 100% without major complications (Table 5). There was no significant difference in the minor complication distribution between two groups using chi-square test (p = 0.050). The minor complication in ALT group was hematoma, and the complications in RFFF group were infection and dehiscence.