Analysis of 13 cases of venous compromise in 178 radial forearm free flaps for intraoral reconstruction

Abstract

The purpose of this study was to analyse the causes of venous compromise and flap failure in radial forearm free flap (RFFF) surgery for intraoral reconstruction. One hundred seventy-eight RFFF reconstructions were reviewed retrospectively for intraoral defects. Of the 13 flaps with venous obstruction, 9 flaps were salvaged, and 4 were lost, with a salvage rate of 69.2%. Eleven venous occlusions occurred within the first 72 h. The main reasons for venous failure were mechanical obstruction or technical errors due to inadequate pedicle length and geometry, inadequate venous drainage, compression and kinking of the vein. The main cause of failure for oropharynx reconstruction was unrecognized vascular events due to the lack of reliable monitoring for buried flap. Oozing of dusky blood from the flap margin may be directly related to venous congestion in the early postoperative period and a late indication of a change in skin colour. In conclusion, a thorough operative plan, including carefully selected drainage vein for the flap and recipient vessels, adequate pedicle length and geometry, precise surgical technique, avoidance of haematoma, and expert monitoring of buried flaps may improve the success rate of RFFF transfer in intraoral reconstruction.

Microvascular free tissue transfer is a reliable method for reconstructing complex surgical defects in the head and neck. Different reconstructive options are available for specific anatomical regions. The radial forearm free flap (RFFF) is characterized by outstanding modelling ability, thinness, technically simple flap harvesting, and a long, wide-calibre vascular pedicle. This type of flap can be harvested concurrently with surgery in the oral and maxillofacial area without any problem, and is therefore the most commonly used type of free flap used in this area. RFFF has become the most reliable flap regarding survival. A success rate over 95% is not uncommon in an experienced centre, but there is still a small risk of flap compromise necessitating urgent reexploration. Some recent large series of free tissue transfers report a reexploration rate of 3.7–8.2% and salvage rates range of 44.9–80%, venous thrombosis is more common than arterial thrombosis and has a higher salvage rate.

Previous reports have confirmed that the success of flap salvage has been directly related to early recognition and timely surgical intervention. Many large series of free tissue transfer included mixed case series (breast, head and neck, extremity) and did not distinguish arterial and venous failure in each category. There are few detailed data on RFFF with venous failure following intraoral reconstruction. The authors present 13 cases of venous compromise in 178 RFFFs for intraoral reconstruction, and discuss factors that influenced the results.

Materials and methods

A retrospective review of 178 RFFFs used for intraoral soft tissue reconstruction in 178 patients (121 men and 57 women) with a median age of 52 years (range 17–84 years) between 1991 and 2010 in the authors’ department was performed. The harvest of flap, selection of drainage vein and recipient vessel, microvascular anastomoses and postoperative management were performed as previously presented. Postoperatively, close monitoring of the exposed flaps in the first 72 h after surgery was performed by 2-hourly bedside assessment and pinprick testing when colour, tactility, capillary refill, bleeding, and appearance of the flap suggested a vascular problem. The frequency of flap monitoring was reduced to every 4 h thereafter until the patient was discharged. When there was a change in skin colour, senior medical staff were called to assess the flap. If the change suggested vascular compromise, patients were taken back to the operating room, usually within 1–2 h, for reexploration.

Flaps that were buried were evaluated with electronic fibre endoscopy (PENTAX EPM-1000) daily for the first 3 days in selected cases or not monitored at all.

All patients who required emergent reexploration after operation were identified and their hospital records were reviewed. Patient demographics, the sites of reconstruction, the timing of flap compromise, the type of vascular occlusion (arterial or venous), drainage veins and recipient veins, the causes of vascular occlusion, and the salvage rate were recorded and analysed. Fisher’s exact test and Wilcoxon rank sum test were used for statistical analysis wherever appropriate. A P value of less than 0.05 was considered statistically significant.

Results

One hundred seventy-eight RFFF reconstructions of intraoral malignancy resections were performed. Thirteen flaps (7.3%) developed signs of vascular obstruction postoperatively that necessitated surgical exploration. None of these flaps had arterial failure. There were no false-positive and false-negative results. Nine of those flaps were salvageable, and four were lost, with a salvage rate of 69.2%.

Of the 13 patients with venous obstruction, 9 were male and 4 were female, with a median age of 52 years (range 31–73 years). The incidences of venous compromise and flap failure for sex and each site of surgical defect are listed in Table 1 . The rates of venous compromise were 7.4% in men and 7% in women (Fisher’s exact test, P = 1.000) and the flap failure rates were 2.5% and 1.8%, respectively (Fisher’s exact test, P = 1.000), the differences were insignificant. The flap compromise rate was highest for palate (14.3%) reconstruction, but the site of the defect was not a significant predictor of venous compromise (Fisher’s exact test, P = 0.653). Oropharynx reconstruction had a significantly higher rate (9.1%) of flap failure than reconstruction at other sites (Fisher’s exact test, P = 0.021).

Table 1
Incidence of venous compromise and flap failure by sex and site of defect.
Total flaps Venous compromise Flap failure
Defects Male Female Male Female Male Female
Tongue 54 31 6(11.1) 1(3.2) 0 0
Buccal area 24 15 1(4.2) 2(13.3) 1(4.2) 1(6.7)
Palate 10 4 1(10) 1(25) 1(10) 0
Gingiva 9 4 0 0 0 0
Mouth floor 14 2 0 0 0 0
Oropharynx 10 1 1(10) 0 1(10) 0
Total 121 57 9(7.4) 4(7) 3(2.5) 1(1.8)
Note : Values in parentheses are percentages.

The timing of venous compromise and flap failure were analysed ( Table 2 ). Eleven flaps (85%) were surgically explored within the first 72 h after surgery, and the salvage rate was 82%. Two flaps were compromised more than 72 h after surgery, and neither was salvageable. Table 3 shows the causes and outcomes of venous compromise. Seven flaps (7/13) with venous pedicle problems had mechanical obstruction due to inadequate pedicle length and geometry (3/7), haematoma compression (2/7) and kinking (2/7) of the vein. Three flaps had inadequate drainage from the cephalic vein that required additional anastomosis with the venae comitantes. Three venous thromboses occurred without a clearly documented cause. The incidences of venous compromise and flap failure in the different flap drainage veins and recipient veins were assessed statistically ( Table 4 ). There were no statistical differences in venous compromise and flap failure rate in the flaps using the dual flap drainage veins (superficial and deep venous system) as compared with those with the single flap drainage vein (superficial venous system) only (Fisher’s exact test, P = 1.000 and 1.000, respectively). The analysis of neck recipient vein demonstrated no significant differences between different recipient veins in venous compromise and flap failure rate (Fisher’s exact test, P = 0.742 and 0.308, respectively).

Table 2
Timing of venous compromise and flap failure.
Timing Venous compromise Flap failure
<24 h 5 1(20)
24–48 h 5 1(20)
48–72 h 1 0
72 h–7 days 2 2(100)
Total 13 4(30.8)
Values in parentheses are percentages.

Table 3
Causes and outcomes of venous compromise.
Number Outcomes
Causes Salvaged Failure
Inadequate pedicle length and geometry 3 2 1
Haematoma compression 2 1 1
Kinking of the pedicle vein 2 1 1
Inadequate cephalic vein drainage 3 3 0
Unknown reasons 3 2 1
Total 13 9 4

Table 4
Incidence of venous compromise and flap failure by drainage vein and recipient vein.
Drainage vein Venous compromise Flap failure
Recipient vein CV and VC CV CV and VC CV CV and VC CV
EJV 77 84 6(7.8) 6(7.1) 2(2.6) 1(1.2)
IJV 0 10 0 1(10) 0 1(10)
EJV and IJV 3 4 0 0 0 0
Total 80 98 6(7.5) 7(7.1) 2(2.5) 2(2.0)
EJV: external jugular vein; IJV: internal jugular vein; CV: cephalic vein; and VC: venae comitantes.
Values in parentheses are percentages.

All flaps requiring reexploration, except one buried flap, had a change in skin colour from the distal margin towards the proximal part within several hours and skin colour gradually became duskier. Four of these twelve patients developed venous failure with oozing of dusky blood from the flap margin at first, and returned to the operating room for reexploration due to a change in skin colour following oozing decrease. The median time from end of initial surgery to detection of venous failure (TED) and the median time from end of initial surgery to reexploration (TER) were significantly longer in patients with a change in skin colour following oozing decrease than in patients with a change in skin colour only ( Table 5 ; Wilcoxon rank sum test, P = 0.010 and 0.041, respectively). The failed buried flap (without monitoring) had an increase of drainage fluid, the colour of which gradually became duskier after the third postoperative day, bleeding occurred in the oral cavity and neck wound at 90 h postoperatively, reexploration was performed immediately, but the flap was totally necrotic with venous thrombosis.

Jan 26, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Analysis of 13 cases of venous compromise in 178 radial forearm free flaps for intraoral reconstruction
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