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Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction
YBJOM-5850;
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ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction Z. Chen, M. Yu, S. Huang, S. Zhang, W. Li, D. Zhang ∗ Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250000, China Accepted 11 November 2019
Abstract Our aim was to record our preliminary use of a microvascular coupler for arterial anastomoses with free flap transfer in the reconstruction of oral and maxillofacial defects in 45 patients with oral and maxillofacial defects that were repaired with anterolateral thigh, fibular, and radial forearm flaps. The microvascular coupler was used for both the venous and the arterial anastomoses. The site of the defect, type of flap, recipient artery, duration of operating time for the anastomosis, size of coupler, and survival of the flap were recorded and analysed. A total of 45 consecutive patients had microsurgical reconstructions in the head and neck, including 16 radial forearm, 18 fibular, and 11 anterolateral thigh free flaps. The sizes of coupler required ranged from 1.5-2.5 mm, with most flaps (n = 30) requiring a 2.0 mm coupler. The mean (SD) operating time for arterial anastomoses was 7 (2) mins. One arterial crisis occurred during an operation, and required a sutured anastomosis instead. There were no complications related to the technical performance of the coupler. The coupler is reliable for arterial anastomoses of free tissue transfers in reconstructions of the head and neck. With proper selection of vessels and enough experience in using the microvascular coupler, it may be used in an expeditious, safe, and reliable fashion with minimal morbidity. Though not common, the use of the coupler for arterial anastomoses saves a lot of time, and is a viable alternative to a sutured anastomosis. © 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: microvascular coupling device; arterial anastomosis; oral and maxillofacial reconstruction; free tissue transfer
Introduction Microvascular free tissue transfers, which are now routinely used to reconstruct patients’ facial appearance and repair functions such as swallowing, mastication, and speech, have become the conventional treatment for many complex soft or hard tissue defects that result from resection of squamous cell carcinomas, salivary gland neoplasms, sarcomas, and primary bone neoplasms as well as defects related to osteoradionecrosis, trauma, and facial paralysis.1,2 The success
∗
Corresponding author. E-mail address: [email protected] (D. Zhang).
of free flaps, and the clinical efficacy of reconstruction, rely on the quality of the microvascular anastomosis, which is deemed to be the most challenging and important technique. With improvement and standardisation of the microvascular hand-sewn technique, the clinical success of free flaps is 95% - 98%,3,4 and this is still the gold standard.5 However, advanced anastomotic devices have been developed to aid microvascular anastomoses, and the ring pin anastomotic coupling device has been proved to be the most reliable. Several papers have described the ease of use and reliability of these, which can be used in venous anastomoses in all areas of the body with patency rates equal to or surpassing those for sutured anastomoses.6–8 However, despite the widespread use of couplers for venous anastomoses, we
https://doi.org/10.1016/j.bjoms.2019.11.011 0266-4356/© 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
YBJOM-5850;
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ARTICLE IN PRESS Z. Chen et al. / British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
know of few reports about their clinical use in arterial anastomoses. This study is therefore a retrospective review of our experience using the coupler for arterial anastomoses in oral and maxillofacial reconstruction from December 2015December 2017 at the Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong University (Jinan, China). Patients and methods All microsurgical free flap reconstructions done from December 2015-December 2017 at the Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong University were reviewed retrospectively. A total of 45 patients had microsurgical reconstructions of the head and neck with the use of the coupling devices not only for venous, but also for arterial, anastomoses. Patients’ personal and clinical information including age, sex, past medical history (hypertension, diabetes mellitus, coronary artery disease, and history of radiation to the head and neck), site of the defect, type of flap, recipient artery, duration of anastomosis, size of coupler, and flap survival, was collected and analysed. Signed informed consent was obtained from each participant preoperatively. A lead surgeon completed all arterial anastomoses assisted by one of two assistant surgeons. In each case a single vein and a single artery were anastomosed with microvascular couplers. Flaps and both donor and recipient vessels were prepared appropriately for microsurgery. The microvascular anastomotic coupler (Synovis Micro Companies Alliance, Baxter International) was used according to the manufacturer’s instructions. The diameter of the anastomotic ring ranges from 1.0-4.0 mm, increasing at 0.5-mm intervals. Unlike with a venous anastomosis, the elasticity and intima of the arteries should be evaluated before anastomosis because of their diameter and the thickness of the wall. We used a transparent glass scale with a minimum scale of 0.1 mm to measure the diameter and thickness of the wall of the artery to be anastomosed (Fig. 1). Criteria for suitability for use of the arterial microvascular coupling device were: the arterial wall should be less than 0.4 mm thick and the intima intact; the arterial diameter should be more than, or equal to, 1.5 mm; it should be possible to expand the vascular wall physically and mechanically (dilated blood vessel diameter - thickness of the vessel wall x 2 ≥ the diameter of the blood vessel before dilatation); and discrepancies in the luminal diameter of the donor and recipient arteries should be less than 0.5 mm. Only when these criteria have been met can the integrity of the vascular intima and elastic dilatation be guaranteed and the arterial wall be everted 90◦ . The third criterion was included to ensure that the effective passage of blood after the application of the microvascular coupling device is better than that of hand-sewn anastomosis. The vessel ends were needed to mount on the coupler rings, everting
Fig. 1. A transparent glass scale with a minimum scale of 0.1 mm was used to measure the diameter and wall thickness of the anastomotic artery.
Fig. 2. The ends of the recipient and donor vessels were passed through the lumen of the coupler and everted on the tips of the coupler ring.
each vessel wall 90◦ , which enabled complete visualisation of the two lumens. The ends of the recipient and donor vessels were then passed through the lumen of the coupler, everted on the tips of the coupler ring, and the two rings secured in apposition using a fine haemostat before the instrument was separated from the rings (Figs. 2 and 3).
Results During the specified time we studied a total of 45 consecutive patients who had microsurgical reconstructions of
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
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Table 2 Recipient artery (n = 45). Recipient artery
No
Superior thyroid Lingual Transverse cervical Facial
14 2 2 27
Table 3 Duration of operating time for arterial anastomosis (n = 45).
Fig. 3. Microvascular coupling device applied to anastomosis of facial artery and peroneal artery with free fibular flap transfer (arrow). Table 1 Sites of defects and flaps used (n = 45). Defect and flap used
No. of defects
Floor of mouth: Radial forearm Fibular Tongue: Radial forearm Anterolateral thigh Buccal mucosa: Radial forearm Mandible: Fibular Mandibular gingiva: Anterolateral thigh Fibular
8
No. of flaps 6 2
13 7 6 3 3 14 14 7 5 2
the head and neck (27 male and 18 female; male:female ratio 1.5:1; mean (range) age 52 (18-71) years). We used 16 radial forearm, 18 fibular, and 11 anterior lateral thigh free flaps. Their previous history included hypertension (n = 10), coronary artery disease (n = 8), diabetes mellitus (n = 5), and radiotherapy (n = 3). The causes or the surgical defect were malignant (n = 34) or benign (n = 11) tumours, and the main sites are shown in Table 1. Ninety couplers were used in these patients, half were used for arteries, and the size of couplers for arterial anastomoses ranged from 1.5-2.5 mm in diameter. The 2.0 mm couplers were used in 30 cases, the 2.5 mm ones in 11, and the 1.5 mm ones in only four. The recipient vessels are shown in Table 2. The mean (SD) duration of operating time for arterial anastomoses with couplers was 7 (2) minutes and the range is shown in Table 3, while those anastomosed by hand sewing took 21 (1) (range 18-24) minutes in our previous studies. This difference is significant (p = 0.0001).
Operating time (minutes)
No.
12 11 10 9 8 7 6 5 4
1 1 1 3 2 9 16 10 2
We also compared the interclass equilibration, involving age, sex, course of disease, and other related information, and found that the differences among these data were not significant. The duration of operation for arterial anastomosis was longer than that for venous anastomosis because the arterial wall was thicker and less elastic. There was one operative arterial thrombosis among the 45 arterial anastomoses. It was in a 67-year-old man with a history of hypertension and diabetes, for whom a radial forearm flap was being used to repair a defect in the floor of the mouth. Atherosclerosis of the radial and facial arteries was found intraoperatively. After the arteries had been evaluated, the 2.0 mm coupler was used. After half an hour the flap was examined because the pulse was weak and the reflux venous strangulation test showed that it was not patent. The coupler was removed, thrombosis was found at the anastomotic site, and the arterial anastomosis was hand sewn instead. Another flap developed a venous thrombosis on the second postoperative day. The anterolateral thigh free flap was removed and the defect reconstructed during the operation with the anterolateral thigh free flap from the other side. Both flaps were finally successful.
Discussion Free tissue transfers for reconstructions in the head and neck grew in popularity in the past,9,10 their success being dependent on many variables, including the quality and reliability of the anastomosis. While traditional hand-sewn techniques have been the gold standard,11 there are several potential problems with this technique, such as adequate eversion of the vessel that may lead to exposure of the adventitia (which is highly thrombogenic), and poor placement of sutures that may result in anastomotic leaks.12 Compared with handsewn techniques, anastomotic coupling devices have become
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
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increasingly popular in microvascular anastomoses because a series of studies have reported that they could simplify anastomoses and the transfer of free flaps, and provide an overall reduction in the duration of the time taken to do an anastomosis, the ischaemic time, and the incidence of microvascular complications.11–13 For a long time, these coupling devices have been mainly used for venous anastomoses. We know of only a few reports that have described the selective application of microvascular anastomoses because: first, compared with veins, arteries are difficult to turn over because of their thick walls and lack of elasticity; secondly, atherosclerosis is likely to develop in older patients with a history of hypertension and diabetes; and thirdly, the arterial wall is likely to fibrose if radiotherapy has been used. All these factors increase the difficulty of arterial anastomoses and the risk of failure. Ahn et al14 described intraoperative thromboses in five of 29 arterial anastomoses and 24 successful arterial couplings without any artery-related complications. In the same study, however, nearly three-quarters of the arterial anastomoses were hand sewn. Because that series described a heterogeneous group of flaps, there was a tendency towards variation in the size and thickness of flap and recipient arteries. Shindo et al15 reported a series of 16 arterial anastomoses after resections of the head and neck, in which two coupled arteries thrombosed. They concluded that arterial coupling was often suboptimal for use in reconstructions in the head and neck as the recipient arteries in that region tended to be thick-walled and were often scarred by previous irradiation. A recent series by Ross et al12 described the successful use of the coupling device for arterial microanastomoses in 49 of 50 consecutive free tissue transfers in the head and neck. Additionally, Spector et al16 used coupling devices in 62 cases with no failure of flaps, but with one return to the operating theatre for revision of an arterial anastomosis. Their mean time for arterial anastomosis using the coupling device was five minutes, and they concluded that (with careful selection of the vessel and enough experience using a coupler) arterial coupling is safe and reliable with minimal morbidity. The advantage of reconstructions in the head and neck lies in the fact that there are multiple arterial systems such as the facial artery, superior thyroid artery, and transverse cervical artery, which can provide arteries of different diameters with the matching of vessels in the flap. This is also the theoretical basis for the better use of microvascular coupling devices for arterial anastomosis in oral and maxillofacial reconstruction. Based on these considerations, and after mastering the technique of microvascular coupling in venous anastomoses, we have gradually started using it for arterial anastomoses. At present, we have done a total of 45 cases, of which one was changed to manual suture because of an arterial vascular crisis during operation. The cause of failure was considered to be severe atherosclerosis, a relatively thick vessel wall, and poor elasticity, resulting in stenosis of the vessel lumen and insufficient blood supply to the artery. Another cause may be turbulence in blood flow leading to arterial
thrombosis. Another flap developed venous thrombosis on the second postoperative day, the anterolateral thigh free flap was removed, and the defect reconstructed with the anterolateral thigh free flap from the other side intraoperatively. All the other flaps had good blood flow and no vascular crisis occurred. We found that successful perfusion of the flap was based on the surgeons, who were extremely proficient with the use of the microvascular coupling device and experienced in harvesting flaps, selecting the recipient vessels and donor sites, and making sure that the vascular pedicle was not twisted. The thicker and more elastic walls of arteries sometimes remain more resistant to piercing by the coupler pins and they fall out easily.12 In this case, the assistant must be quick to fix the arterial wall on to the tine beside the part that the surgeon is holding. Another skill is to hang the arterial wall far from the handle to prevent the ring slipping. Our experience has also indicated that thickness and elastic dilatation of the arterial vessel walls play a part in predicting when an arterial anastomosis should be hand-sewn. The use of couplers may be made more difficult if either the donor or recipient artery is too thick-walled, as adequate eversion of the edges over the pins becomes technically difficult and leads to reduced laminar blood flow and possibly even complete obstruction of the vessel lumen. Additionally, coupling is not suitable for end-to-side arterial anastomosis or when the discrepancies in the arterial luminal diameter of the donor and recipient vessels are greater than a 1.5:1 ratio. Other authors16 have also noted this, and laid down some rules for proper selection of vessels, such as avoiding discrepancies of more than a 1.5:1 ratio in arterial luminal diameter and making sure that the walls of selected arteries are easy to evert. From these cases, we drew the following conclusions: the arterial walls should not be too thick and the intima should be intact; the donor and recipient arteries that are dilated to accommodate a ring size should not be less than 1.5 mm in diameter; it should be possible to expand vascular walls physically and mechanically to ensure effective blood flow after the application of the microvascular coupling device; and the discrepancy between the luminal diameters of the donor and recipient arteries should be less than 0.5 mm, which is the smallest interval for the coupler. During the operations, we used a high-precision scale to measure and evaluate the diameter and thickness of the arterial wall, which was not reported in previous papers. It guaranteed that the arterial wall could be smoothly everted 90◦ , and that the artery would not become narrow as a result of the extrusion of the coupler ring after anastomosis. Compared with the hand-sewn techniques, anastomotic coupling devices have become increasingly popular because a series of studies have confirmed our conclusions. However, the microvascular coupling device cannot completely replace the hand-sewn anastomosis. Its use is based on the techniques of microsurgery. Only by strict training in microsurgical techniques can we better master various new microvascu-
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
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lar anastomotic techniques. Unlike previous papers that have described the use of microvascular coupling device in arteries, we have selected not only the thickness of the arterial wall, but have also evaluated the elasticity and degree of dilatation of the artery. This provides experience and guidance for the clinical use of the microvascular coupling device for arterial anastomosis. It deserves more widespread use for reconstruction of the head and neck by free flaps. Meanwhile, coupling for arterial anastomosis should be used only after proper selection of vessels by surgeons with sufficient experience. Conflict of interest We have no conflicts of interest. Ethics statement/confirmation of patients’ permission The Ethics Committee of Shandong Provincial Hospital approved the protocol, and all patients gave their informed consent to participation. References 1. Kessler P, Poort L, Bockmann R, et al. Definition of quality indications in microsurgery in head and neck reconstruction based on a 5-year follow-up without a loss. J Craniomaxillofac Surg 2013;41:2–6. 2. Frederick JW, Sweeny L, Carroll WR, et al. Microvascular anastomotic coupler assessment in head and neck reconstruction. Otolaryngol Head Neck Surg 2013;149:67–70. 3. Pohlenz P, Klatt J, Schon G, et al. Microvascular free flaps in head and neck surgery: complications and outcome of 1000 flaps. Int J Oral Maxillofac Surg 2012;41:739–43.
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4. Frederick JW, Sweeny L, Carroll WR, et al. Outcomes in head and neck reconstruction by surgical site and donor site. Laryngoscope 2013;123:1612–7. 5. Zhang T, Lubek J, Salama A, et al. Venous anastomoses using microvascular coupler in free flap head and neck reconstruction. J Oral Maxillofac Surg 2012;70:992–6. 6. Nakatsuka T, Harii K, Asato H, et al. Analytic review of 2372 free flaptransfers for head and neck reconstruction following cancer resection. J Reconstr Microsurg 2003;19:363–9. 7. Schubert HM, Schoeller T, Wechselberger G. 1000 consecutive venous anastomoses using the microvascular anastomotic coupler in breast reconstruction. Plast Reconstr Surg 2010;126:1789. 8. Patel SA, Pang JH, Natoli N, et al. Reliability of venous couplers for microanastomosis of the venae comitantes in free radial forearm flaps for head and neck reconstruction. J Reconstr Microsurg 2013;29:433–6. 9. Urken ML, Weinberg H, Buchbinder D, et al. Microvascular free flaps in head andneck reconstruction: report of 200 cases and review of complications. Arch Otolaryngol Head Neck Surg 1994;120:633–40. 10. Yap LH, Constantinides J, Butler CE. Venous thrombosis in coupled versus sutured microvascular anastomoses. Ann Plast Surg 2006;57:666–9. 11. DeLacure MD, Kuriakose MA, Spies AL. Clinical experience in end to side venous anastomoses with a microvascular anastomotic coupling device in head and neck reconstruction. Arch Otolaryngol Head Neck Surg 1999;125:869–72. 12. Ross DA, Chow JY, Shin J, et al. Arterial coupling for microvascular free tissue transfer in head and neck reconstruction. Arch Otolaryngol Head Neck Surg 2005;131:891–5. 13. Chernichenko N, Ross DA, Shin J, et al. Arterial coupling for microvascular free tissue transfer. Otolaryngol Head Neck Surg 2008;138:614–8. 14. Ahn CY, Shaw WW, Berns S, et al. Clinical experience with the 3M microvascular coupling anastomotic device in 100 free-tissue transfers. Plast Reconstr Surg 1994;93:1481–4. 15. Shindo ML, Costantino PD, Nalbone VP, et al. Use of a mechanical microvascular anastomotic device in head and neck free tissue transfer. Arch Otolaryngol Head Neck Surg 1996;122:529–32. 16. Spector JA, Draper LB, Levine JP, et al. Routine use of microvascular coupling device for arterial anastomosis in breast reconstruction. Ann Plast Surg 2006;56:365–8.
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
No. of Pages 5
ARTICLE IN PRESS Available online at www.sciencedirect.com
ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction Z. Chen, M. Yu, S. Huang, S. Zhang, W. Li, D. Zhang ∗ Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250000, China Accepted 11 November 2019
Abstract Our aim was to record our preliminary use of a microvascular coupler for arterial anastomoses with free flap transfer in the reconstruction of oral and maxillofacial defects in 45 patients with oral and maxillofacial defects that were repaired with anterolateral thigh, fibular, and radial forearm flaps. The microvascular coupler was used for both the venous and the arterial anastomoses. The site of the defect, type of flap, recipient artery, duration of operating time for the anastomosis, size of coupler, and survival of the flap were recorded and analysed. A total of 45 consecutive patients had microsurgical reconstructions in the head and neck, including 16 radial forearm, 18 fibular, and 11 anterolateral thigh free flaps. The sizes of coupler required ranged from 1.5-2.5 mm, with most flaps (n = 30) requiring a 2.0 mm coupler. The mean (SD) operating time for arterial anastomoses was 7 (2) mins. One arterial crisis occurred during an operation, and required a sutured anastomosis instead. There were no complications related to the technical performance of the coupler. The coupler is reliable for arterial anastomoses of free tissue transfers in reconstructions of the head and neck. With proper selection of vessels and enough experience in using the microvascular coupler, it may be used in an expeditious, safe, and reliable fashion with minimal morbidity. Though not common, the use of the coupler for arterial anastomoses saves a lot of time, and is a viable alternative to a sutured anastomosis. © 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: microvascular coupling device; arterial anastomosis; oral and maxillofacial reconstruction; free tissue transfer
Introduction Microvascular free tissue transfers, which are now routinely used to reconstruct patients’ facial appearance and repair functions such as swallowing, mastication, and speech, have become the conventional treatment for many complex soft or hard tissue defects that result from resection of squamous cell carcinomas, salivary gland neoplasms, sarcomas, and primary bone neoplasms as well as defects related to osteoradionecrosis, trauma, and facial paralysis.1,2 The success
∗
Corresponding author. E-mail address: [email protected] (D. Zhang).
of free flaps, and the clinical efficacy of reconstruction, rely on the quality of the microvascular anastomosis, which is deemed to be the most challenging and important technique. With improvement and standardisation of the microvascular hand-sewn technique, the clinical success of free flaps is 95% - 98%,3,4 and this is still the gold standard.5 However, advanced anastomotic devices have been developed to aid microvascular anastomoses, and the ring pin anastomotic coupling device has been proved to be the most reliable. Several papers have described the ease of use and reliability of these, which can be used in venous anastomoses in all areas of the body with patency rates equal to or surpassing those for sutured anastomoses.6–8 However, despite the widespread use of couplers for venous anastomoses, we
https://doi.org/10.1016/j.bjoms.2019.11.011 0266-4356/© 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
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know of few reports about their clinical use in arterial anastomoses. This study is therefore a retrospective review of our experience using the coupler for arterial anastomoses in oral and maxillofacial reconstruction from December 2015December 2017 at the Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong University (Jinan, China). Patients and methods All microsurgical free flap reconstructions done from December 2015-December 2017 at the Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong University were reviewed retrospectively. A total of 45 patients had microsurgical reconstructions of the head and neck with the use of the coupling devices not only for venous, but also for arterial, anastomoses. Patients’ personal and clinical information including age, sex, past medical history (hypertension, diabetes mellitus, coronary artery disease, and history of radiation to the head and neck), site of the defect, type of flap, recipient artery, duration of anastomosis, size of coupler, and flap survival, was collected and analysed. Signed informed consent was obtained from each participant preoperatively. A lead surgeon completed all arterial anastomoses assisted by one of two assistant surgeons. In each case a single vein and a single artery were anastomosed with microvascular couplers. Flaps and both donor and recipient vessels were prepared appropriately for microsurgery. The microvascular anastomotic coupler (Synovis Micro Companies Alliance, Baxter International) was used according to the manufacturer’s instructions. The diameter of the anastomotic ring ranges from 1.0-4.0 mm, increasing at 0.5-mm intervals. Unlike with a venous anastomosis, the elasticity and intima of the arteries should be evaluated before anastomosis because of their diameter and the thickness of the wall. We used a transparent glass scale with a minimum scale of 0.1 mm to measure the diameter and thickness of the wall of the artery to be anastomosed (Fig. 1). Criteria for suitability for use of the arterial microvascular coupling device were: the arterial wall should be less than 0.4 mm thick and the intima intact; the arterial diameter should be more than, or equal to, 1.5 mm; it should be possible to expand the vascular wall physically and mechanically (dilated blood vessel diameter - thickness of the vessel wall x 2 ≥ the diameter of the blood vessel before dilatation); and discrepancies in the luminal diameter of the donor and recipient arteries should be less than 0.5 mm. Only when these criteria have been met can the integrity of the vascular intima and elastic dilatation be guaranteed and the arterial wall be everted 90◦ . The third criterion was included to ensure that the effective passage of blood after the application of the microvascular coupling device is better than that of hand-sewn anastomosis. The vessel ends were needed to mount on the coupler rings, everting
Fig. 1. A transparent glass scale with a minimum scale of 0.1 mm was used to measure the diameter and wall thickness of the anastomotic artery.
Fig. 2. The ends of the recipient and donor vessels were passed through the lumen of the coupler and everted on the tips of the coupler ring.
each vessel wall 90◦ , which enabled complete visualisation of the two lumens. The ends of the recipient and donor vessels were then passed through the lumen of the coupler, everted on the tips of the coupler ring, and the two rings secured in apposition using a fine haemostat before the instrument was separated from the rings (Figs. 2 and 3).
Results During the specified time we studied a total of 45 consecutive patients who had microsurgical reconstructions of
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
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Table 2 Recipient artery (n = 45). Recipient artery
No
Superior thyroid Lingual Transverse cervical Facial
14 2 2 27
Table 3 Duration of operating time for arterial anastomosis (n = 45).
Fig. 3. Microvascular coupling device applied to anastomosis of facial artery and peroneal artery with free fibular flap transfer (arrow). Table 1 Sites of defects and flaps used (n = 45). Defect and flap used
No. of defects
Floor of mouth: Radial forearm Fibular Tongue: Radial forearm Anterolateral thigh Buccal mucosa: Radial forearm Mandible: Fibular Mandibular gingiva: Anterolateral thigh Fibular
8
No. of flaps 6 2
13 7 6 3 3 14 14 7 5 2
the head and neck (27 male and 18 female; male:female ratio 1.5:1; mean (range) age 52 (18-71) years). We used 16 radial forearm, 18 fibular, and 11 anterior lateral thigh free flaps. Their previous history included hypertension (n = 10), coronary artery disease (n = 8), diabetes mellitus (n = 5), and radiotherapy (n = 3). The causes or the surgical defect were malignant (n = 34) or benign (n = 11) tumours, and the main sites are shown in Table 1. Ninety couplers were used in these patients, half were used for arteries, and the size of couplers for arterial anastomoses ranged from 1.5-2.5 mm in diameter. The 2.0 mm couplers were used in 30 cases, the 2.5 mm ones in 11, and the 1.5 mm ones in only four. The recipient vessels are shown in Table 2. The mean (SD) duration of operating time for arterial anastomoses with couplers was 7 (2) minutes and the range is shown in Table 3, while those anastomosed by hand sewing took 21 (1) (range 18-24) minutes in our previous studies. This difference is significant (p = 0.0001).
Operating time (minutes)
No.
12 11 10 9 8 7 6 5 4
1 1 1 3 2 9 16 10 2
We also compared the interclass equilibration, involving age, sex, course of disease, and other related information, and found that the differences among these data were not significant. The duration of operation for arterial anastomosis was longer than that for venous anastomosis because the arterial wall was thicker and less elastic. There was one operative arterial thrombosis among the 45 arterial anastomoses. It was in a 67-year-old man with a history of hypertension and diabetes, for whom a radial forearm flap was being used to repair a defect in the floor of the mouth. Atherosclerosis of the radial and facial arteries was found intraoperatively. After the arteries had been evaluated, the 2.0 mm coupler was used. After half an hour the flap was examined because the pulse was weak and the reflux venous strangulation test showed that it was not patent. The coupler was removed, thrombosis was found at the anastomotic site, and the arterial anastomosis was hand sewn instead. Another flap developed a venous thrombosis on the second postoperative day. The anterolateral thigh free flap was removed and the defect reconstructed during the operation with the anterolateral thigh free flap from the other side. Both flaps were finally successful.
Discussion Free tissue transfers for reconstructions in the head and neck grew in popularity in the past,9,10 their success being dependent on many variables, including the quality and reliability of the anastomosis. While traditional hand-sewn techniques have been the gold standard,11 there are several potential problems with this technique, such as adequate eversion of the vessel that may lead to exposure of the adventitia (which is highly thrombogenic), and poor placement of sutures that may result in anastomotic leaks.12 Compared with handsewn techniques, anastomotic coupling devices have become
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
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increasingly popular in microvascular anastomoses because a series of studies have reported that they could simplify anastomoses and the transfer of free flaps, and provide an overall reduction in the duration of the time taken to do an anastomosis, the ischaemic time, and the incidence of microvascular complications.11–13 For a long time, these coupling devices have been mainly used for venous anastomoses. We know of only a few reports that have described the selective application of microvascular anastomoses because: first, compared with veins, arteries are difficult to turn over because of their thick walls and lack of elasticity; secondly, atherosclerosis is likely to develop in older patients with a history of hypertension and diabetes; and thirdly, the arterial wall is likely to fibrose if radiotherapy has been used. All these factors increase the difficulty of arterial anastomoses and the risk of failure. Ahn et al14 described intraoperative thromboses in five of 29 arterial anastomoses and 24 successful arterial couplings without any artery-related complications. In the same study, however, nearly three-quarters of the arterial anastomoses were hand sewn. Because that series described a heterogeneous group of flaps, there was a tendency towards variation in the size and thickness of flap and recipient arteries. Shindo et al15 reported a series of 16 arterial anastomoses after resections of the head and neck, in which two coupled arteries thrombosed. They concluded that arterial coupling was often suboptimal for use in reconstructions in the head and neck as the recipient arteries in that region tended to be thick-walled and were often scarred by previous irradiation. A recent series by Ross et al12 described the successful use of the coupling device for arterial microanastomoses in 49 of 50 consecutive free tissue transfers in the head and neck. Additionally, Spector et al16 used coupling devices in 62 cases with no failure of flaps, but with one return to the operating theatre for revision of an arterial anastomosis. Their mean time for arterial anastomosis using the coupling device was five minutes, and they concluded that (with careful selection of the vessel and enough experience using a coupler) arterial coupling is safe and reliable with minimal morbidity. The advantage of reconstructions in the head and neck lies in the fact that there are multiple arterial systems such as the facial artery, superior thyroid artery, and transverse cervical artery, which can provide arteries of different diameters with the matching of vessels in the flap. This is also the theoretical basis for the better use of microvascular coupling devices for arterial anastomosis in oral and maxillofacial reconstruction. Based on these considerations, and after mastering the technique of microvascular coupling in venous anastomoses, we have gradually started using it for arterial anastomoses. At present, we have done a total of 45 cases, of which one was changed to manual suture because of an arterial vascular crisis during operation. The cause of failure was considered to be severe atherosclerosis, a relatively thick vessel wall, and poor elasticity, resulting in stenosis of the vessel lumen and insufficient blood supply to the artery. Another cause may be turbulence in blood flow leading to arterial
thrombosis. Another flap developed venous thrombosis on the second postoperative day, the anterolateral thigh free flap was removed, and the defect reconstructed with the anterolateral thigh free flap from the other side intraoperatively. All the other flaps had good blood flow and no vascular crisis occurred. We found that successful perfusion of the flap was based on the surgeons, who were extremely proficient with the use of the microvascular coupling device and experienced in harvesting flaps, selecting the recipient vessels and donor sites, and making sure that the vascular pedicle was not twisted. The thicker and more elastic walls of arteries sometimes remain more resistant to piercing by the coupler pins and they fall out easily.12 In this case, the assistant must be quick to fix the arterial wall on to the tine beside the part that the surgeon is holding. Another skill is to hang the arterial wall far from the handle to prevent the ring slipping. Our experience has also indicated that thickness and elastic dilatation of the arterial vessel walls play a part in predicting when an arterial anastomosis should be hand-sewn. The use of couplers may be made more difficult if either the donor or recipient artery is too thick-walled, as adequate eversion of the edges over the pins becomes technically difficult and leads to reduced laminar blood flow and possibly even complete obstruction of the vessel lumen. Additionally, coupling is not suitable for end-to-side arterial anastomosis or when the discrepancies in the arterial luminal diameter of the donor and recipient vessels are greater than a 1.5:1 ratio. Other authors16 have also noted this, and laid down some rules for proper selection of vessels, such as avoiding discrepancies of more than a 1.5:1 ratio in arterial luminal diameter and making sure that the walls of selected arteries are easy to evert. From these cases, we drew the following conclusions: the arterial walls should not be too thick and the intima should be intact; the donor and recipient arteries that are dilated to accommodate a ring size should not be less than 1.5 mm in diameter; it should be possible to expand vascular walls physically and mechanically to ensure effective blood flow after the application of the microvascular coupling device; and the discrepancy between the luminal diameters of the donor and recipient arteries should be less than 0.5 mm, which is the smallest interval for the coupler. During the operations, we used a high-precision scale to measure and evaluate the diameter and thickness of the arterial wall, which was not reported in previous papers. It guaranteed that the arterial wall could be smoothly everted 90◦ , and that the artery would not become narrow as a result of the extrusion of the coupler ring after anastomosis. Compared with the hand-sewn techniques, anastomotic coupling devices have become increasingly popular because a series of studies have confirmed our conclusions. However, the microvascular coupling device cannot completely replace the hand-sewn anastomosis. Its use is based on the techniques of microsurgery. Only by strict training in microsurgical techniques can we better master various new microvascu-
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011
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lar anastomotic techniques. Unlike previous papers that have described the use of microvascular coupling device in arteries, we have selected not only the thickness of the arterial wall, but have also evaluated the elasticity and degree of dilatation of the artery. This provides experience and guidance for the clinical use of the microvascular coupling device for arterial anastomosis. It deserves more widespread use for reconstruction of the head and neck by free flaps. Meanwhile, coupling for arterial anastomosis should be used only after proper selection of vessels by surgeons with sufficient experience. Conflict of interest We have no conflicts of interest. Ethics statement/confirmation of patients’ permission The Ethics Committee of Shandong Provincial Hospital approved the protocol, and all patients gave their informed consent to participation. References 1. Kessler P, Poort L, Bockmann R, et al. Definition of quality indications in microsurgery in head and neck reconstruction based on a 5-year follow-up without a loss. J Craniomaxillofac Surg 2013;41:2–6. 2. Frederick JW, Sweeny L, Carroll WR, et al. Microvascular anastomotic coupler assessment in head and neck reconstruction. Otolaryngol Head Neck Surg 2013;149:67–70. 3. Pohlenz P, Klatt J, Schon G, et al. Microvascular free flaps in head and neck surgery: complications and outcome of 1000 flaps. Int J Oral Maxillofac Surg 2012;41:739–43.
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4. Frederick JW, Sweeny L, Carroll WR, et al. Outcomes in head and neck reconstruction by surgical site and donor site. Laryngoscope 2013;123:1612–7. 5. Zhang T, Lubek J, Salama A, et al. Venous anastomoses using microvascular coupler in free flap head and neck reconstruction. J Oral Maxillofac Surg 2012;70:992–6. 6. Nakatsuka T, Harii K, Asato H, et al. Analytic review of 2372 free flaptransfers for head and neck reconstruction following cancer resection. J Reconstr Microsurg 2003;19:363–9. 7. Schubert HM, Schoeller T, Wechselberger G. 1000 consecutive venous anastomoses using the microvascular anastomotic coupler in breast reconstruction. Plast Reconstr Surg 2010;126:1789. 8. Patel SA, Pang JH, Natoli N, et al. Reliability of venous couplers for microanastomosis of the venae comitantes in free radial forearm flaps for head and neck reconstruction. J Reconstr Microsurg 2013;29:433–6. 9. Urken ML, Weinberg H, Buchbinder D, et al. Microvascular free flaps in head andneck reconstruction: report of 200 cases and review of complications. Arch Otolaryngol Head Neck Surg 1994;120:633–40. 10. Yap LH, Constantinides J, Butler CE. Venous thrombosis in coupled versus sutured microvascular anastomoses. Ann Plast Surg 2006;57:666–9. 11. DeLacure MD, Kuriakose MA, Spies AL. Clinical experience in end to side venous anastomoses with a microvascular anastomotic coupling device in head and neck reconstruction. Arch Otolaryngol Head Neck Surg 1999;125:869–72. 12. Ross DA, Chow JY, Shin J, et al. Arterial coupling for microvascular free tissue transfer in head and neck reconstruction. Arch Otolaryngol Head Neck Surg 2005;131:891–5. 13. Chernichenko N, Ross DA, Shin J, et al. Arterial coupling for microvascular free tissue transfer. Otolaryngol Head Neck Surg 2008;138:614–8. 14. Ahn CY, Shaw WW, Berns S, et al. Clinical experience with the 3M microvascular coupling anastomotic device in 100 free-tissue transfers. Plast Reconstr Surg 1994;93:1481–4. 15. Shindo ML, Costantino PD, Nalbone VP, et al. Use of a mechanical microvascular anastomotic device in head and neck free tissue transfer. Arch Otolaryngol Head Neck Surg 1996;122:529–32. 16. Spector JA, Draper LB, Levine JP, et al. Routine use of microvascular coupling device for arterial anastomosis in breast reconstruction. Ann Plast Surg 2006;56:365–8.
Please cite this article in press as: Chen Z, et al. Preliminary report of the use of a microvascular coupling device for arterial anastomoses in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.011