Abstract
Importance
The closure technique for the radial forearm free flap (RFFF), a commonly utilized flap in head and neck reconstruction, remains a debated topic as there are unique advantages and drawbacks to each technique.
Objective
The present study aims to report on the outcomes of the closure of the RFFF with the superficial cephalic vein (CV)-only system in terms of venous compromise and flap survival.
Methods (Design, Setting, Participants, Intervention, Measures)
A retrospective review of patients who underwent head and neck reconstruction with RFFF between January 2015 and May 2021 at the authors’ institution was performed. Cases were categorized as superficial, dual, and deep systems. Multiple population and operative variables were collected for the study group.
Results
In total, 221 cases of RFFF were included, of which 169 (76.5%) cases were performed using the CV alone, whereas the remaining 52 (22.5%) cases utilized either the dual or the deep system alone. The operative time in the superficial group was 265 minutes. There were 9 venous complications in the CV group, of which 5 required re-exploration in the operating room and 4 were treated conservatively. All venous-related flap complications were salvaged.
Conclusion and Relevance
A majority of the RFFF cases could successfully be completed using the CV as the sole venous drainage, with high rates of flap survival, low complications, and low operative time.
Introduction
Since its original description in 1981, 1 the radial forearm free flap (RFFF) has been the most widely used free flap in head and neck surgery. 2 It is thin, easy to harvest, offers a long pedicle, and can be designed for most oral and maxillofacial surgical defects. RFFF survival depends on a multitude of factors including successful anastomosis of the artery and vein, vessel geometry as well as choosing the appropriate venous drainage system. Most flap failures are due to venous drainage issues rather than arterial 3 and therefore the choice of, and method for, venous anastomosis has been discussed for nearly 3 decades. 4 The RFFF offers 2 systems of venous drainage, the superficial and deep. The superficial system consists of the cephalic vein (CV) while the deep system consists of 2 paired vena comitans (VCs) that travel adjacent to the radial artery.
The selection of the most suitable drainage system for RFFF remains a controversial topic. In its original description, while the dual venous drainage system was recommended, the superficial CV system was regarded as the primary venous drainage. 1 This was subsequently challenged by anatomical studies that revealed the drainage volume of VCs per unit time was twice that of the CV. 5 Hence, some argue that the VCs alone are more capable than the superficial system in draining the RFFF.5-7 Others emphasize the importance of using both superficial and deep systems to decrease the chance of venous compromise.8,9
Similar to prior reports,3,10,11 at the author’s institution, the CV superficial system is favored because of its greater vessel diameter and relative ease of incorporating it as the main venous drainage. The alternative to the CV is to anastomose the smaller VCs or to perform a more tedious proximal dissection toward the antecubital fossa to identify the confluence of the VC and CV to a single larger vessel.
Despite the common use of RFFF in head and neck reconstruction, no consensus has been reached regarding the most suitable venous system. Based on the author’s clinical experience, we hypothesize that using the CV alone does not negatively impact flap viability. Therefore, the primary aim of this study is to determine the rate of venous outflow compromise of venous drainage using the CV for RFFF reconstruction. A secondary aim is to identify potential risk factors for venous compromise.
Methods
The study was approved by the Institutional Ethics Board at the University of British Columbia (certificate number: H20-02621). A retrospective review of all patients who underwent microvascular head and neck reconstruction using the RFFF at the author’s institution from January 2015 to May 2021 was completed. Population variables including age, body mass index, history of smoking, cancer diagnosis and stage; use of adjuvant and neoadjuvant therapies; and medical comorbidities were collected. Operative variables including duration of surgery, donor and recipient vessels used, and anastomotic technique were also recorded. Patients with insufficient operative information regarding the type of venous drainage were excluded.
The primary outcome variables were the incidence of venous compromise and flap failure. Any documentation of signs of the venous compromise included bluish or cyanotic flap color, brisk bleeding on the pinprick test, increased capillary refill, and the absence of a venous signal on the Doppler ultrasound recorded. If venous compromise was identified, management, either conservatively or return to the operating room, was recorded including the postoperative day of detection, salvage technique, and outcomes.
Statistical Analysis
The significance of all study variables in relation to the venous drainage method and venous compromise rate was assessed, using Chi-Squared or Fisher’s exact test for categorical variables and t-test for continuous variables. Variables with a P-value <.05 were considered significant. All analyses were carried out in Prism 9 version 9.2.0 (Graphpad, San Diego, California, USA).
Results
The retrospective review identified 239 RFFFs, of which 18 were excluded for lack of clearly identifying the type of venous drainage utilized. The overall patient population characteristics are reported in Table 1. Of the 221 RFFFs with complete information, 169 (76.5%) cases were performed using the CV alone, whereas the remaining 52 (22.5%) cases utilized either the dual system [47 cases (21.3%)] or the deep system alone [5 cases (2.2%)] (Figure 1). There was a total of 9 venous complications from the superficial group, with 5 managed by returning to the operating room for which 3 had clot removal and a revision venous anastomosis, 1 had removal of coagulable around the vessels and repositioning, and 1 had no intervention done. Of the remaining 4 treated conservatively, 3 were treated with the application of leeches, and 1 with close observations. All 9 of the venous-related flap complications were salvaged regardless of the salvage technique. The characteristics of the 9 patients who experienced flap complications are listed in Table 2.
Patient Characteristics.
Abbreviation: BMI, body mass index.
Breakdown of RFFFs based on venous drainage and venous compromise. RFFFs, radial forearm free flaps; CV, cephalic vein; VC, vena comitans.
Characteristics of Patients Who Experience Flap Complication Post-Operation.
Abbreviations: F, female; M, male; POD, postoperative day; RFFF, radial forearm free flap; SCC; squamous cell carcinoma.
At our institution, the CV superficial system is the primary choice for the drainage of the RFFF reconstruction. For cases wherein the CV alone was not suitable, the dual system or the VC was employed. Of the 5 cases where only the deep system (VC) was used, 4 were noted to have insufficient drainage from the CV intraoperatively and 1 had an extensive history of chemotherapy with suspicion of CV sclerosis prompting the use of the deep system. However, there was insufficient data to determine why the dual system was chosen for the 47 cases. Due to the unequal groups of patients for each drainage technique, no comparative analysis was performed.
The mean total operating time was 265 minutes, with the single-team approach being 316.5 minutes and the double-team approach being 206.3 minutes. In the univariate analysis, there was no significant association between the incidence of venous compromise and possible risk factors including sex, history of preoperative chemotherapy or radiation, tumor recurrence state, primary tumor site, tumor stage, smoking status, or comorbidities including cerebrovascular disease, diabetes mellitus, and hypertension (Table 3).
Demographics and Clinical Risk Factors of Venous Insufficiency in Our Head and Neck Cancer Patients Who Underwent Reconstruction with RFFF.
Other sites include the salivary gland, orbit, parotid, scalp, and neck.
Discussion
Venous compromise is a serious postoperative complication that could lead to partial or total flap loss. Inadequate outflow and venous thrombosis are reported as 2 common reasons for venous compromise. 9 The reported venous complication rates in the literature for the superficial system range from 1.4% to 11.1%.3,6,8,12-14 In our presented series, the venous complication rate of 5.3% in the superficial system is consistent with prior reports. These findings suggest that the drainage capacity of the CV alone can adequately handle the flow volume generated by the radial artery. Furthermore, all 9 of the venous-related complications in our series were salvaged, 5 with surgical intervention and 4 with conservative care.
CVs are 3 to 6 mm or larger, 15 which allow for an easier hand-sewn anastomosis or use of a venous coupler and contribute to decreasing the operative time. To achieve a greater vessel diameter, and to incorporate the CV and VC systems in a single anastomosis, others have suggested a more proximal dissection toward the antecubital fossa to locate the confluence of the 2 VCs or a communicating vein between the deep and superficial system.16-18 However, the capture of these larger caliber veins requires a more significant, and often time-consuming, proximal dissection. It has been shown that harvesting of the communicating vein involves dissection beyond the antecubital fossa 37% of the time. 18 This may result in an often unnecessarily long pedicle length that may be prone to kinking and subsequent venous compromise. 19 Furthermore, the communication between the deep and superficial systems is absent up to 40% of the time. 18
Proponents of the dual system suggest it provides a “safety valve,”8,20 which preserves partial venous drainage in the event of thrombosis in 1 venous pedicle. Others argue that the additional venous pedicles decrease the venous pressure, and thus the venous outflow from the flap, with a possibly higher risk of venous thrombosis secondary to venous stasis. 11 Those incorporating the dual system require either a second venous anastomosis or a more proximal dissection to the confluence of the VC and CV. In this setting, Futran et al reported that a second anastomosis can add up to 38 minutes to the operative time. 11 In our presented retrospective case series, the total operating time for the CV system is 265 minutes. Prolonged operative time is an independent risk factor for free flap failure, septic shock, need for transfusion, risk for re-operation, and increased length of hospital stay.21-24
Some studies argue that incorporating the CV into the flap requires a dorsolateral extension of the flap, which often results in a less desirable donor site appearance and possible injury to the superficial branch of the radial nerve (SBRN).3,23 The SBRN is a consistent landmark in RFFF harvest and is closely associated with the CV and is certainly within the operative field. It is the author’s experience to always identify the nerve in the distal wrist during the elevation of the skin paddle along the radial/lateral aspect and preserve the medial branches of the SBRN. However, the medial branch of the SBRN might be sacrificed during the harvest leading to some degree of cutaneous anesthesia around the thenar eminence postoperatively.
Our study is limited by its inherent retrospective design and inability to account for confounding variables. In addition, this study represents data from a single institution of 3 microvascular surgeons with a strong preference for harvesting the RFFF based on the CV as the primary venous drainage. Thus, a comparison of the different drainage systems (CV, dual system, or VCs) could not be completed and represents a direction for future research.
Overall, the CV offers a large diameter, does not require routine proximal dissection to the antecubital fossa, and has demonstrated an equivalent rate of venous compromise compared to that reported in the literature.
Conclusion
This study demonstrates that the usage of the CV alone as the primary venous drainage results in low operative time and rate of venous compromise of the RFFF. As well, the reliability and efficiencies of utilizing the Cephalic venous system are discussed.
Footnotes
Acknowledgements
There are no acknowledgments.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
