The Japanese Journal of Surgery (1992) 22:46-54
S :ac, avTot v © Springer-Verlag 1992 '
Sutureless Anastomosis of Blood Vessels Using Cyanoacrylate Adhesives HIROAKI TAKENAKA, KENSUKE ESATO, MASAKI OHARA, and NOBUYA ZEMPO The First Department of Surgery, Yamaguchi University School of Medicine, Ubc, Japan
Abstract: On the assumption that the remaining suture threads of the anastomotic line play an important role in the progression of anastomotic neointimal hyperplasia, we performed an experimental study on the sutureless anastomosis of blood vessels. An expanded polytetrafluoroethylene graft, 5 mm in diameter and 2cm in length, was implanted on the abdominal aorta of mongrel adult using one of three methods of anastomosis, namely; a continuous suture, a stay suture, or sutureless anastomosis. Overall patency rates were 83.3 per cent, 91.7 per cent and 75.0 per cent respectively. The thickness of the pannus in the distal anastomotic line after 12 months was 107 ~tm in one graft in the continuous suture group, 106~tm and 2221am in 2 grafts each in the stay suture group, and 41t~m and ll7pm in 2 grafts each in the sutureless group. Because there were cases of patency even after i2 months with a very small pannus thickness, sutureless anastomosis is considered to be a useful method of preventing anastomotic neointimal hyperplasia.
anastomosed vessels. The factors that contribute to anastomotic neointimal hyperplasia are; (1) injuries to the wails of the blood vessels caused by surgical operations; (2) turbulent blood flow in the anastomotic line; (3) an abnormal reaction of the suture threads to the host; (4) materials used in the prosthesis; and (5) incompatibility of the host vessels to the prosthesis. Based on the assumption that the remaining suture threads of the anastomotic line play an important role in the progression of anastomotic neointimal hyperplasia, we performed an experimental study of sutureless anastomosis between blood vessels and a prosthesis. The purpose of this study was to find out whether sutureless anastomosis using a cyanoacrylate adhesive was potential and effective in the suppression of neointimal hyperplasia.
Key Words: sutureless anastomosis, cyanoacrylate adhesives, anastomotic neointimal hyperplasia
Materials and Methods
Introduction
There has been rapid progress in arterial reconstruction techniques due to advances in prostheses and suture threads. As for late patency rates in arterial reconstructions, more satisfactory results have been obtained in reconstructions on the proximal to common femoral artery. However, the results have been poor in arterial reconstructions in or below the inguinal ligament, especially when a prosthesis of less than 5 m m in internal diameter is used. In the grafting of a prosthesis to smaller vessels, the condition of the pannus formed in the anastomotic line has a great influence on late patency rates in the Reprint requests to: Hiroaki Takeneka, MD, The First Department of Surgery, Yamaguchi University School of Medicine, Ube, 755, Japan (Received for publication on May 2, 1990)
Adult mongrel dogs were anesthetized with an intravenous injection of thiamylal sodium at 10 mg/kg and maintained by the controlled respiration of air through endotracheal intubation. A median abdominal skin incision of about 20 cm was made with the umbilical region as the center, and the abdominal aorta exposed to a point just below the left renal vein on the cranial side. A 1.0cm segment of the abdominal aorta was excised on the cranial side of the inferior mesenteric artery, after which an expanded polytetrafluoroethylene (ePTFE) graft of 2 cm in length and 5 mm in internal diameter was implanted by one of the following three methods: 1. Continuous suture group (13 dogs): The prosthesis was anastomosed to the host vessel by the usual continuous suture using 6-0 polypropylene. 2. Stay suture group (15 dogs): A horizontal mattress stitch was placed on 4 sites around the host vessels and the prosthesis at equal intervals using 6-0
H. Takenaka et al.: Sutureless Anastomosis
47
Fig. 1. The method of sumreless anastomosis A Four stay sutures were placed without ligation and the adhesive was applied. B The suture threads were completely removed polypropylene. These mattress suture threads were ligated and pulled so that the prosthesis could be fastened tightly to the host vessel at the cut end. A cyanoacrylate adhesive was then applied all around the anastomotic line. 3. Sutureless group (19 dogs): A horizontal mattress stitch was placed on 4 sites in the same manner as in the stay suture group. These suture threads were pulled without ligation, after which a cyanoacrylate adhesive was applied all around the anastomotic line. After checking for bleeding from the anastomotic line by declamping the aorta, the suture threads were completely removed (Fig. 1). Prosthetic graft segments obtained at intervals of 1, 3, 6 and 12 months after grafting were split longitudinally; one half being fixed for light micrography and the other half for scanning electron-micrography. No anticoagulants were used during the experiment. Resulls
Twelve animals survived in each group throughout the experiment, the causes and times of death being:
Fig. 2. Abdominal aortogram taken 12 months after grafting in the sutureless group. The anastomotic line (arrows) is smooth severe, persistent diarrhea on the 14th day after grafting in one animal of the continuous group; pneumonia on the lOth and 15th days after grafting, respectively in 2 animals, and an unknown cause in the 3rd month after grafting in one animal of the stay suture group; and massive bleeding immediately after grafting in 5 animals of the sutureless group. Moreover, in the sutureless group, one animal died of intra-abdominal bleeding on the 2nd day after grafting, and another died of a graft infection on the 7th day after grafting. With regard to the 12 animals surviving in each group, 3 from each group were sacrificed at the end of the 1st, 3rd, 6th and 12th months after grafting. 1. Patency Rate Before sacrificing the animals, an angiography was performed on each animal. In the continuous group, patency was obtained in all animals at the end of the 1st, 3rd and 6th months after grafting. At the end of the 12th mo.nth, however, an obstruction was found in
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H. Takenaka et al.: Sutureless Anastomosis
2 of 3 animals. In the stay suture group, patency was obtained in all animals at the end of the 1st, 3rd and 6th months after grafting, however, at the end of the 12th month, an obstruction was found in one animal. In the sutureless group, patency was obtained in all animals at the end of the 1st, 3rd and 12th months, but at the end of the 6th month, an obstruction was found in all 3 animals. Therefore, the 12-month patency rate in the continuous, stay suture and sutureless groups was 33.3 per cent (1/3), 66.7 per cent (2/3) and 100 per cent (3/3) respectively, the overall patency rate being 83.3 per cent (10/12) in the continuous group, 91.7 per cent (11/12) in the stay suture group, and 75.0 per cent (9/12) in the sutureless group. The angiograms done 12 months after grafting in the sutureless group showed that the intraluminal surface was smooth both on the proximal and distal anastomotic lines without deformation and/or stenosis (Fig. 2).
2. Pulling Test Breaking load was measured in one dog from each group at intervals of 1, 3, 6 and 12 months, except for the grafts sacrificed at the end of the 12th month in the continuous group and at the end of the 6th month in the sutureless group (Table 1). The breaking load in each group was nearly the same, with the value ranging from 2000 to 2500 grams. There was no particular tendency for the tensile strength in the sutureless group to be weak. In the sutureless group, at the end of the 12th month, the breaking load on the proximal and distal anastomotic lines was 2300 and 2000 grams, respectively. The tensile strength in the sutureless group did not show a tendency to weaken with time after implantation.
3. Macroscopic Findings In the continuous group, at the end of the 1st and 3rd months after grafting, the pannus, that is, 5 mm wide, beltlike, whitish tissue, had grown to the graft from the aortic intima of the host and covered the anastomotic line. This pannus gradually extended in the 6th and the 12th months to a width of 8 mm. A coarse, reddish fibrin membrane in the intraluminal surface was noted at the end of the 1st and 3rd months. The intraluminal Table 1. Tensile strength of the anastomotic line (grams) Continuous Stay suture Sutureless Months suture group group group after grafting Proximal distal Proximal distal Proximal distal 1 3 6 12
2450 2160 2450 --
2220 2650 2000 --
2560 2100 2320 2410
2710 1850 2250 2380
2400 1500 -2300
1840 2200 -2000
Fig. 3. Macroscopic findings in the sutureless group A (One month): Pannuses have grown about 4mm wide. B (Three months): Pannuses have extended to 7ram wide. C (Twelve months): There is no thrombus formation on the intraluminal surface of the graft surface became whitish and smooth at the end of the 6th month. Spreading of the pannus to the graft in the stay suture group was about the same as in the continuous group. At the end of the 12th month after grafting, the pannus was found to have become whitish and smooth. At the end of the 1st month after grafting, the pannuses in the sutureless group had grown to about 4 mm wide around the graft, and at the end of the 3rd month, had further spread to 7 m m . The intraluminal surface in the mid-portion of the graft was covered with a thin fibrin membrane. At the end of the 12th month, the growth of the pannus was the same as that at the end of the 3rd month. There was no fibrin membrane and the intraluminal surface of the graft was smooth 12 months after grafting (Fig. 3). At the end of the 6th month after grafting in the sutureless group, an organized thrombus was found in the obstructive grafts. These thrombi were presumed to have been caused by the cyanoacrylate adhesive that leaked into the lumen at the time of anastomosis.
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49
Table 2. Thickness of the pseudointima on the distal anastomotic line (gm) Months after Continuous suture Stay suture Sutureless grafting group group group 1
3 6 12
80 280 270 210 128 192 107 --
125 160 75 190 136 333 106 222
140 246 200 180 --41 117
group. Fibroblasts were seen in the pannus, but no newly formed endothelial cells were observed. At the end of the 3rd month, the number of fibroblasts in the pannus decreased. The pannus was very thin, the value being 41gm and l17~m in 2 grafts after 12 months. Thus, complete healing in the intraluminal surface was demonstrated in the anastomotic line (Fig. 7). The cyanoacrylate adhesive still remained on the adventitial sides of the anastomotic line even after 12 months. Inflammatory cellular infiltration in the outer layer of the anastomotic line was observed at the end of the 1st month, but little such infiltration was seen in the grafts taken at the end of the 3rd and 12th months (Fig. 8).
4. Microscopic Findings
5. Scanning Electron-micrographic Findings
Table 2 shows the thickness of the pannus formed on the distal anastomotic line during each observation period in each group. The pannus formed on the distal side of the anastomosis in the continuous group had become smooth at the end of the 1st month, and was comparatively thin, the value being 107 gm in a graft after 12 months (Fig. 4). The newly formed adventitia had already made sufficient growth at the end of the 1st month. The stitched end of the host vessel showed hyalinoid degeneration at the end of the 1st, 6th and 12th months (Fig. 5). The pannus formed on the distal side of the anastomosis in the stay suture group was comparatively thin, the value being 106 pm and 222 gm respectively in 2 grafts after 12 months. Hyalinoid degeneration similar to that in the continuous group was found in 4 sites where suture threads remained (Fig. 6), but in parts where no suture threads were present, no such degeneration was found. At the end of the 1st month, a pannus consisting of connective tissues had grown to the graft beyond the proximal or distal anastomotic lines in the sutureless
In the continuous group, at the end of the ]st month, the intraluminal surfaces of the suture threads remaining in the anastomotic line were covered with a thin fibrous membrane. In some grafts, this thin fibrous membrane was torn off and therefore, the surfaces of the suture threads were exposed to the blood stream. However, the anastomotic line had become smooth with the passage of time, and at the end of the 12th month, no exposure of the blood stream to the surfaces of the suture threads was seen (Fig. 9). In the stay suture group, at the end of the 1st month, the intraluminal surfaces of the staying suture threads were found to have been exposed to the blood stream. In the parts where no suture threads were present, intraluminal surfaces of the anastomotic line were comparatively smooth, though endothelial cells were not demonstrated. At the end of the 3rd month, partly dense and partly rough neointima was found. At the end of the 12th month, the intraluminal surface of the anastomotic line had become smooth, and newly formed endothelial cells were found (Fig. ]0). In the sutureless group, at the end of the 1st month, the intraluminal surface of the graft was covered with
Fig, 4. Photomicrograph one month after grafting in the continuous group (Elastica Van Gieson, x 100). The thickness of the pannus is 107gm. The host vessel shows hyalinoid degeneration (Arrow). H: Host vessel, P: Prosthesis
50
H. Takenaka et al.: Sutureless Anastomosis was found, and the graft fiber was exposed. At the end of the 12th month, the intraluminal surface of the graft had become smooth and completely covered with endothelial cells (Fig. 11). Discussion
Fig. 5. Photomicrographs 6 and 12 months after grafting in the continuous group (Elastica Van Gieson, ×40). A (6 months) B (12 months) Hyalinoid degeneration can be seen (Arrows) platelets and a sparse fibrin net. Platelets were interconnected by dendrite spreading into branches. At the end of the 3rd month, the fibrin net had become dense, and the intraluminal surface of the graft was partly dense and partly rough. At the rough part of the intraluminal surface, no formation of the neointima
The basic manual technique to promote the healing of injuries is to adhere tissues together. For this purpose, the stitching together of tissues with a needle and thread has been used for a long time. Along with advances in surgery, improvements have been made in suturing techniques and materials, but stitching together with a needle, thread and ligation is stil! the basic technique. In the area of vascular surgery too, anastomosis with sutures is generally used, however, experience and skill is required in the anastomosis of small blood vessels, especially in a heparinized state, and thus, anastomotic procedures are not always safe and easy. What has the most influence on the strength of the anastomosed part in the long term after an operation is the density and volume of the newly formed adventitia in the anastomosed part. That is to say, in arterial reconstructions using a prosthesis, the required function of the sutures is simply to keep the host blood vessel and prosthesis fastened tightly together for a certain period. Therefore, the presence of suture threads for a long period of time is harmful, since these suture threads are likely to cause infection, inflammation and anastomotic neointimal hyperplasia. For this reason, we performed the present experiment so as to develop a technique for the sutureless anastomosis of blood vessels. At present, two methods are being used both experimentally and clinically for the sutureless anastomosis of
Fig. 6. Photomicrograph 12 months after grafting in the stay suture group (Elastica Van Gieson, ×10). Hyalinoid degeneration was found. (Arrow) H: Host vessel, P: Prosthesis
H. Takenaka et al.: Sutureless Anastomosis
Fig. 7. Photomicrographs in the sutureless group. A (One month Elastica Van Gieson, × 10): The pannus is 140 ~m. B (Three months Elastica Van Gieson, ×10): The pannus is 200~m. C (Twelve months Hematoxylin and eosin, ×10): The pannus has become 41 ~m, and there are neointimal cells present. H: Host vessel, P: Prosthesis, Arrows: Pannus blood vessels, one being the laser method and the other the adhesive method. The laser method is a comparatively new method, first used in 1970 by Jain et al. a in closing incised small vessels. Since Morris et al. 2 reported in 1980 on their actual application of a laser to the anastomosis of blood vessels, there have been many reports, however, no reports have been made yet about the grafting of prostheses using a laser. Though we tried to implant an e P T F E graft or a knitted Dacron graft using a CO2 laser, no adhesion was obtained at the anastomotic line. On the other hand, adhesives have been used for the successful anastomosis of blood vessels. Adhesives require properties such as sterility, quick yet strong adhesion, no toxicity, no foreign body reaction and the potential for use in the presence of some water. There are two adhesives which satisfy the above requirements: one is fibrin glue, and the other a cyanoacrylate adhesive.
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Fig. 8. Photomicrographs in the sutureless group (Elastica Van Gieson, × 100). A (One month): Inflammatory cellular infiltration can be observed. B (Twelve months): Inflammatory cellular infiltration is not seen. Arrows: cyanoacrylate adhesives
Fibrin glue is an adhesive which was developed based on the fact that in the healing process of injuries in the living body, fibrinogen solidifies to form fibrin nets, which have an adhesive action. There are many reports on the anastomosis of blood vessels with the use of fibrin glue. However, in the anastomosis of arteries, fibrin glue is used as an auxiliary in most cases after several stitches have been made for fixing the sutures. 3,4 In the anastomosis of blood vessels using fibrin glue, there are cases in which anastomosis was obtained successfully without leaving even a single piece of the sutures. 5'6 However, the adhesive action of the fibrin glue is very weak immediately after application, and therefore, it cannot be used in a high pressure area such as the arterial system. As for prosthesis, we tried to implant knitted Dacron grafts, human umbilical cord vein grafts ( H U C V G ) and e P T F E grafts. When using the knitted Dacron graft, the adhesive filtered out to the intraluminal surface of the graft and it is suspected of causing thrombosis. As for H U C V G , it was difficult to tightly fasten the host vessel and graft pulling 4 stay sutures. However, there
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H. Takenaka et al.: Sutureless Anastomosis
Fig. 9. Scanning electron micrographs in the continuous group A (One month, ×70): Suture threads are covered with a thin fibrous membrane. B (Twelve months, ×700): The anastomotic line is smooth were no such problems in using the ePTFE graft, and so we used this graft. Regarding the binding mechanism of the cyanoacrylate type adhesive, a cyanoacrylate monomer forms polymer chains in the presence of a small amount of water. It gains adhesion quickly, and its adhesive power is very strong, however, it has the drawback that when applied it hardens strongly and as a result, lacks elasticity. The alkyl-2-cyanoacrylates belongs to a class of vinyl monomer and its structural formula is represented as: CH2
JCN C"-COO - R
The alkyl side chain ( - R ) determines the speed of polymerization, flexibility, and toxicity. 17 The methyl compound (short chain) has high flexibility, but it is much too toxic to the host vessels and its polymerizing speed too slow. Contrary to this, the butyl compound (long chain) has less flexibility, less toxicity and a more
Fig. 10. Scanning electron micrographs in the stay suture group A (One month, xT0): The staying sutures (arrow) are exposed. B (Three months, x220): Newly formed intima has developed. C (Twelve months, x700): The anastomotic line is smooth
rapid polymerizing speed. Thus, we determined to use ethyl-2-cyanoacrylate monomer, which is an intermediate type compound. The application of cyanoacrylate adhesives to the medical field was started in about 1960. In the area of vascular surgery, in the early stages there were many reports on the direct closure or repair of arterial incisions. 7-9 Regarding applications to the anastomosis of blood vessels, all reports focused on the anastomosis of blood vessels in the living body. In addition, cyanoacrylate adhesives were used as an auxiliary after placing several stay sutures. 1°-12 When cyanoacrylate adhesives were used, the resulting complications were mainly bleeding in the early stages and aneurysmal dilatation in the later stages. 9 In our experiment, 7 animals out of 19 died in the sutureless group and of these 7, 5 died of massive bleeding which occurred immediately after removal of the aortic clamps. These 5 animals which died of bleeding were operated on during the early period in this experiment. The cause of
H. Takenaka et al.: Sutureless Anastomosis
Fig. 11. Scanning electron micrographs in the sutureless group A (One month, x1750): The intraluminal surface is covered with a rough fibrin net and the platelets. B (Three months, x450): The fibrin net has become dense. C (Twelve months, x450): The intraluminal surface is covered with neointimal cells
the massive bleeding was technical errors such as the insufficient application of adhesive or inadequate compression to the anastomotic part at the time of pulling away the stay sutures. There was no aneurysmal dilatation seen in any of the animals. It was considered necessary to apply the adhesive evenly around the anastomotic line, however, our impression was that when too much adhesive was applied, it simply hardened around the anastomosed part without sufficiently exhibiting its adhesive power in the anastomosis between the prosthesis and the host vessel. In this connection, it is reported to be a tendency that the thicker the layer the adhesive is the weaker the adhesive power becomes. 13 According to Tschopp, 12 it is important to apply just a small quantity to minimize the heat from polymerization and the chemical toxicity. When using cyanoacrylate adhesives, we too tried to apply the minimum amount necessary. There was no pseudo-
53 aneurysm seen in the anastomotic line and there were no decreases in the tensile strength of the anastomotic line even 12 months after grafting in our experiment. Concerning vital reactions to cyanoacrylate adhesives, Jacobson et al., 13 who applied cyanoacrylate adhesives to the anastomotic line of the blood vessels of mongrel adult dogs, reported the following results: After 12 hours, there were acute reactions, and after 72 hours, necrosis spread to the entire part of the media. On and after the 4th day, fibroblasts began to invade the necrotic part of the media, and after 3 months, the necrotic media had been completely replaced by fibrous tissue. After 6 months, both media and intima had become normal except for chronic inflammation around the sutures. Such toxicity of the adhesives is considered to be due to heat from polymerization, formaldehyde and alkyl cyanoacetate, which are decomposed products of the cyanoacrylate polymer. 12'14 In our experiment, inflammatory reactions around the anastomotic line, which were seen at the end of the 1st month, were not observed at the end of the 3rd month and later. Furthermore, the pannus in the anastomotic line after 12 months in the sutureless group was thinner than that in the continuous suture and stay suture groups and new endothelial cells were formed in the regular manner in the scanning electronmicrograph. Thus, cyanoacrylate adhesives did not produce any harmful effects on the healing of the anastomotic line in the long term. Moreover, according to examination by optical microscopes, hyalinoid degeneration was seen from the 1st month in the continuous suture and stay suture groups in the parts where sutures were present, but no such degeneration was observed in the sutureless group. There is a report 15 that such hyalinoid degeneration is due to ischemia caused by sutures present for a long time in the anastomotic line. In this respect, sutureless anastomosis using an adhesive is considered to be more advantageous than anastomosis with suture threads. However, cyanoacrylate adhesives have the following drawbacks: Firstly, the internal diameter of the blood vessels used in our experiment was 5 mm. The problem is whether cyanoacrylate adhesives can be used for blood vessels smaller than 5 mm in internal diameter. Cyanoacrylate adhesives cause necrosis in the adventitia and media, however, in comparatively large vessels of 3-5 mm in internal diameter, the toxicity is less likely to cause thrombus in the lumen. On the other hand, in smaller blood vessels with an internal diameter of 0.5-2 mm, inflammation spreads into the intima, causing hyperplasia of the intima, aneurysmal dilatation and thrombus. 7A6'17 Therefore, it is considered impossible to us6 cyanoacrylate adhesives for the sutureless anastomosis of blood vessels 2 mm or less in internal diameter. 18
54
Secondly, cyanoacrylate adhesives are not absorbed into the living body permanently. Cyanoacrylate adhesives remained on the adventitial side of the anastomosed part even after 12 months. It is desirable in the anastomosis of vessels to use adhesives which remain only for a short term until the adventitia becomes organized and eventually absorbed into the living body. Finally, the elasticity of the adhesion is poor in this cyanoacrylate adhesive, which brings about incompatibility with the blood vessels of the living body. It is feared that this incompatibility may lead to anastomotic neointimal hyperplasia. In our experiment, the patency rate in the sutureless group within 1-12 months after grafting was unsatisfactory, the value being 75.0 per cent. Obstructions were due to a thrombosed lumen caused by the adhesive which leaked into the lumen. In the sutureless anastomosis of blood vessels using an adhesive, it is most important that the prosthesis is tightly fastened to the host vessel so that the adhesive does not leak into the lumen. For this purpose, various techniques are being employed such as the overlapping of the host vessel with the prosthesis, the use of special devices such as the stent and ring, and so forth. 9'19 However, stenosis and deformation at the anastomotic line are unavoidable in each of these techniques. We applied the adhesive to the sutured line while pulling the stay sutures so that the host vessels and prosthesis could be fastened together tightly with each other. After that, the suture threads were removed. Since we did not put any foreign body into the anastomosed part, no deformation or stenosis occurred at the anastomotic line. Technically, the anastomosis could be easily performed, provided care was taken to fasten the prosthesis tightly to the host vessel at the cut end by evenly pulling the 4 stay sutures. At present, there are very few reports about the grafting of prostheses with the use of an adhesive. In our experiment, however, there were cases of patency even after one year. In addition, the pannus was equal to or smaller in thickness than that formed in animals sutured by a conventional continuous suture, or by stay sutures on 4 sites followed by the application of an adhesive. These results lead us to consider the fact that it would be possible to clinically apply this method of grafting with an adhesive. The sutureless anastomosis of blood vessels has been stopped over the past several years and yet, it has now been found that it is not impossible to perform a sutureless anastomosis if easyto-remove polypropylene sutures are used. It is hoped
H. Takenaka et al.: Sutureless Anastomosis
that in the future better manual techniques will be developed so that the adhesive will not leak into the lumen, and at the same time a more satisfactory adhesive will be made.
References 1. Jain KK, Gorisch W (1979) Repair of small blood vessels with the Neodymium YAG laser: A preliminary report. Surgery 85: 684-688 2. Morris JR, Carter M (1980) Laser-assisted microvascular anastomosis (LAMA). (abstr) Las Vegas: Orthopedic Research Society 3. Ikossi-O'Conner MG, Ambrus JL, Uma Rao (1983) The role of fibrin adhesive in vascular surgery. J Surg Oncol 23:151-15 4. Decleer W, Vanhove M, Coenen L, Boeckx W, Grunwez JA (1985) Fibrinous tissue glue in artery anastomosis. Physiological, histological and scanning evaluation. Acta chir belg 85:121-124 5. Brunner FX (1984) Histological findings in sutured and fibringlued microvascular anastomosis.Arch Otorhinolaryngol 240: 311-318 6. Gestring GF, Lerner R Requena R (1983) The sutureless microanastomosis. Vasc Surg 17:364-3. 7. Carton CA, Heifetz MD, Kessler LA (1962) Patching of intracranial internal carotid artery in man using a plastic adhesive (Eastman 910 adhesive). J Neurosurg 19:887-896 8. Nathan HS, Nachlas MM, Solomon RD, Halpern BD, Seligman AM (1960) Nonsuture closure of arterial incisions using a rapidlypolymerizing adhesive. Ann Surg 152:648-65 9. Carton CA, Kessler LA, Seidenberg B, Hurwitt ES (1961) Experimental studies in surgery of small blood vessels. J Neurosurg 18:188-194 10. Hosbein DJ, Blumenstock DA (1964) Anastomosis of small arteries using a tissue adhesive. Surg Gyn Obst 118:112-114 11. Hafner CD, Fogarty TJ, Cranley JJ (1963) Nonsuture anastomosis of small arteries using a tissue adhesive. Surg Gyn Obst 116:417-421 12. Tschopp HM (1975) Small artery anastomosis using a cuff of dura mater and a tissue adhesive. Plas and Reconstr Surg 55:606-611 13. Jacobson JH, Moody RA, Kusserow BK, Reich T, Wang MCH (1966) The tissue response to a plastic adhesive used in combination with microsurgical technique in reconstruction of small arteries. Surgery 60:379-385 14. Gottlob R, Blumel G (1967) The toxic action of alkylcyanoacrylate adhesives on vessels. J Surg Res 7:362-367 15. Naoe A (1989) The role of suture material on healing of vascular anastomosis. Nippon Geka Gakkai Zasshi (J Jpn Surg Soc) 90:941-948. (in Japanese with English Abst.) 16. Hoppenstein RH, Weissberg D, Goetz RH (1965) Fusiform dilatation and thrombosis of arteries following the application of methyl-2-cyanoacrylate (Eastman 910 monomer). J Neurosurg 23:556-564 17. Vinters HV, Galil KA, Lundie MJ, Kaufmann JCE (1985) The histotoxicity of cyanoacrylates. Neuroradiol 27:279-291 18. Weisberg D, Schwartz P, Goetz RH (1966) Nonsuture end-toside anastomosis of blood vessels. Surg Gyn Obst 123:341-346 19. Yamagata S (1982) Experimental studies of nonsuture microvascular anastomosis using soluble PVA tube and plastic adhesive. (in Japanese with English Abst.) Arch Jpn Chir 51:104117
S :ac, avTot v © Springer-Verlag 1992 '
Sutureless Anastomosis of Blood Vessels Using Cyanoacrylate Adhesives HIROAKI TAKENAKA, KENSUKE ESATO, MASAKI OHARA, and NOBUYA ZEMPO The First Department of Surgery, Yamaguchi University School of Medicine, Ubc, Japan
Abstract: On the assumption that the remaining suture threads of the anastomotic line play an important role in the progression of anastomotic neointimal hyperplasia, we performed an experimental study on the sutureless anastomosis of blood vessels. An expanded polytetrafluoroethylene graft, 5 mm in diameter and 2cm in length, was implanted on the abdominal aorta of mongrel adult using one of three methods of anastomosis, namely; a continuous suture, a stay suture, or sutureless anastomosis. Overall patency rates were 83.3 per cent, 91.7 per cent and 75.0 per cent respectively. The thickness of the pannus in the distal anastomotic line after 12 months was 107 ~tm in one graft in the continuous suture group, 106~tm and 2221am in 2 grafts each in the stay suture group, and 41t~m and ll7pm in 2 grafts each in the sutureless group. Because there were cases of patency even after i2 months with a very small pannus thickness, sutureless anastomosis is considered to be a useful method of preventing anastomotic neointimal hyperplasia.
anastomosed vessels. The factors that contribute to anastomotic neointimal hyperplasia are; (1) injuries to the wails of the blood vessels caused by surgical operations; (2) turbulent blood flow in the anastomotic line; (3) an abnormal reaction of the suture threads to the host; (4) materials used in the prosthesis; and (5) incompatibility of the host vessels to the prosthesis. Based on the assumption that the remaining suture threads of the anastomotic line play an important role in the progression of anastomotic neointimal hyperplasia, we performed an experimental study of sutureless anastomosis between blood vessels and a prosthesis. The purpose of this study was to find out whether sutureless anastomosis using a cyanoacrylate adhesive was potential and effective in the suppression of neointimal hyperplasia.
Key Words: sutureless anastomosis, cyanoacrylate adhesives, anastomotic neointimal hyperplasia
Materials and Methods
Introduction
There has been rapid progress in arterial reconstruction techniques due to advances in prostheses and suture threads. As for late patency rates in arterial reconstructions, more satisfactory results have been obtained in reconstructions on the proximal to common femoral artery. However, the results have been poor in arterial reconstructions in or below the inguinal ligament, especially when a prosthesis of less than 5 m m in internal diameter is used. In the grafting of a prosthesis to smaller vessels, the condition of the pannus formed in the anastomotic line has a great influence on late patency rates in the Reprint requests to: Hiroaki Takeneka, MD, The First Department of Surgery, Yamaguchi University School of Medicine, Ube, 755, Japan (Received for publication on May 2, 1990)
Adult mongrel dogs were anesthetized with an intravenous injection of thiamylal sodium at 10 mg/kg and maintained by the controlled respiration of air through endotracheal intubation. A median abdominal skin incision of about 20 cm was made with the umbilical region as the center, and the abdominal aorta exposed to a point just below the left renal vein on the cranial side. A 1.0cm segment of the abdominal aorta was excised on the cranial side of the inferior mesenteric artery, after which an expanded polytetrafluoroethylene (ePTFE) graft of 2 cm in length and 5 mm in internal diameter was implanted by one of the following three methods: 1. Continuous suture group (13 dogs): The prosthesis was anastomosed to the host vessel by the usual continuous suture using 6-0 polypropylene. 2. Stay suture group (15 dogs): A horizontal mattress stitch was placed on 4 sites around the host vessels and the prosthesis at equal intervals using 6-0
H. Takenaka et al.: Sutureless Anastomosis
47
Fig. 1. The method of sumreless anastomosis A Four stay sutures were placed without ligation and the adhesive was applied. B The suture threads were completely removed polypropylene. These mattress suture threads were ligated and pulled so that the prosthesis could be fastened tightly to the host vessel at the cut end. A cyanoacrylate adhesive was then applied all around the anastomotic line. 3. Sutureless group (19 dogs): A horizontal mattress stitch was placed on 4 sites in the same manner as in the stay suture group. These suture threads were pulled without ligation, after which a cyanoacrylate adhesive was applied all around the anastomotic line. After checking for bleeding from the anastomotic line by declamping the aorta, the suture threads were completely removed (Fig. 1). Prosthetic graft segments obtained at intervals of 1, 3, 6 and 12 months after grafting were split longitudinally; one half being fixed for light micrography and the other half for scanning electron-micrography. No anticoagulants were used during the experiment. Resulls
Twelve animals survived in each group throughout the experiment, the causes and times of death being:
Fig. 2. Abdominal aortogram taken 12 months after grafting in the sutureless group. The anastomotic line (arrows) is smooth severe, persistent diarrhea on the 14th day after grafting in one animal of the continuous group; pneumonia on the lOth and 15th days after grafting, respectively in 2 animals, and an unknown cause in the 3rd month after grafting in one animal of the stay suture group; and massive bleeding immediately after grafting in 5 animals of the sutureless group. Moreover, in the sutureless group, one animal died of intra-abdominal bleeding on the 2nd day after grafting, and another died of a graft infection on the 7th day after grafting. With regard to the 12 animals surviving in each group, 3 from each group were sacrificed at the end of the 1st, 3rd, 6th and 12th months after grafting. 1. Patency Rate Before sacrificing the animals, an angiography was performed on each animal. In the continuous group, patency was obtained in all animals at the end of the 1st, 3rd and 6th months after grafting. At the end of the 12th mo.nth, however, an obstruction was found in
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H. Takenaka et al.: Sutureless Anastomosis
2 of 3 animals. In the stay suture group, patency was obtained in all animals at the end of the 1st, 3rd and 6th months after grafting, however, at the end of the 12th month, an obstruction was found in one animal. In the sutureless group, patency was obtained in all animals at the end of the 1st, 3rd and 12th months, but at the end of the 6th month, an obstruction was found in all 3 animals. Therefore, the 12-month patency rate in the continuous, stay suture and sutureless groups was 33.3 per cent (1/3), 66.7 per cent (2/3) and 100 per cent (3/3) respectively, the overall patency rate being 83.3 per cent (10/12) in the continuous group, 91.7 per cent (11/12) in the stay suture group, and 75.0 per cent (9/12) in the sutureless group. The angiograms done 12 months after grafting in the sutureless group showed that the intraluminal surface was smooth both on the proximal and distal anastomotic lines without deformation and/or stenosis (Fig. 2).
2. Pulling Test Breaking load was measured in one dog from each group at intervals of 1, 3, 6 and 12 months, except for the grafts sacrificed at the end of the 12th month in the continuous group and at the end of the 6th month in the sutureless group (Table 1). The breaking load in each group was nearly the same, with the value ranging from 2000 to 2500 grams. There was no particular tendency for the tensile strength in the sutureless group to be weak. In the sutureless group, at the end of the 12th month, the breaking load on the proximal and distal anastomotic lines was 2300 and 2000 grams, respectively. The tensile strength in the sutureless group did not show a tendency to weaken with time after implantation.
3. Macroscopic Findings In the continuous group, at the end of the 1st and 3rd months after grafting, the pannus, that is, 5 mm wide, beltlike, whitish tissue, had grown to the graft from the aortic intima of the host and covered the anastomotic line. This pannus gradually extended in the 6th and the 12th months to a width of 8 mm. A coarse, reddish fibrin membrane in the intraluminal surface was noted at the end of the 1st and 3rd months. The intraluminal Table 1. Tensile strength of the anastomotic line (grams) Continuous Stay suture Sutureless Months suture group group group after grafting Proximal distal Proximal distal Proximal distal 1 3 6 12
2450 2160 2450 --
2220 2650 2000 --
2560 2100 2320 2410
2710 1850 2250 2380
2400 1500 -2300
1840 2200 -2000
Fig. 3. Macroscopic findings in the sutureless group A (One month): Pannuses have grown about 4mm wide. B (Three months): Pannuses have extended to 7ram wide. C (Twelve months): There is no thrombus formation on the intraluminal surface of the graft surface became whitish and smooth at the end of the 6th month. Spreading of the pannus to the graft in the stay suture group was about the same as in the continuous group. At the end of the 12th month after grafting, the pannus was found to have become whitish and smooth. At the end of the 1st month after grafting, the pannuses in the sutureless group had grown to about 4 mm wide around the graft, and at the end of the 3rd month, had further spread to 7 m m . The intraluminal surface in the mid-portion of the graft was covered with a thin fibrin membrane. At the end of the 12th month, the growth of the pannus was the same as that at the end of the 3rd month. There was no fibrin membrane and the intraluminal surface of the graft was smooth 12 months after grafting (Fig. 3). At the end of the 6th month after grafting in the sutureless group, an organized thrombus was found in the obstructive grafts. These thrombi were presumed to have been caused by the cyanoacrylate adhesive that leaked into the lumen at the time of anastomosis.
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49
Table 2. Thickness of the pseudointima on the distal anastomotic line (gm) Months after Continuous suture Stay suture Sutureless grafting group group group 1
3 6 12
80 280 270 210 128 192 107 --
125 160 75 190 136 333 106 222
140 246 200 180 --41 117
group. Fibroblasts were seen in the pannus, but no newly formed endothelial cells were observed. At the end of the 3rd month, the number of fibroblasts in the pannus decreased. The pannus was very thin, the value being 41gm and l17~m in 2 grafts after 12 months. Thus, complete healing in the intraluminal surface was demonstrated in the anastomotic line (Fig. 7). The cyanoacrylate adhesive still remained on the adventitial sides of the anastomotic line even after 12 months. Inflammatory cellular infiltration in the outer layer of the anastomotic line was observed at the end of the 1st month, but little such infiltration was seen in the grafts taken at the end of the 3rd and 12th months (Fig. 8).
4. Microscopic Findings
5. Scanning Electron-micrographic Findings
Table 2 shows the thickness of the pannus formed on the distal anastomotic line during each observation period in each group. The pannus formed on the distal side of the anastomosis in the continuous group had become smooth at the end of the 1st month, and was comparatively thin, the value being 107 gm in a graft after 12 months (Fig. 4). The newly formed adventitia had already made sufficient growth at the end of the 1st month. The stitched end of the host vessel showed hyalinoid degeneration at the end of the 1st, 6th and 12th months (Fig. 5). The pannus formed on the distal side of the anastomosis in the stay suture group was comparatively thin, the value being 106 pm and 222 gm respectively in 2 grafts after 12 months. Hyalinoid degeneration similar to that in the continuous group was found in 4 sites where suture threads remained (Fig. 6), but in parts where no suture threads were present, no such degeneration was found. At the end of the 1st month, a pannus consisting of connective tissues had grown to the graft beyond the proximal or distal anastomotic lines in the sutureless
In the continuous group, at the end of the ]st month, the intraluminal surfaces of the suture threads remaining in the anastomotic line were covered with a thin fibrous membrane. In some grafts, this thin fibrous membrane was torn off and therefore, the surfaces of the suture threads were exposed to the blood stream. However, the anastomotic line had become smooth with the passage of time, and at the end of the 12th month, no exposure of the blood stream to the surfaces of the suture threads was seen (Fig. 9). In the stay suture group, at the end of the 1st month, the intraluminal surfaces of the staying suture threads were found to have been exposed to the blood stream. In the parts where no suture threads were present, intraluminal surfaces of the anastomotic line were comparatively smooth, though endothelial cells were not demonstrated. At the end of the 3rd month, partly dense and partly rough neointima was found. At the end of the 12th month, the intraluminal surface of the anastomotic line had become smooth, and newly formed endothelial cells were found (Fig. ]0). In the sutureless group, at the end of the 1st month, the intraluminal surface of the graft was covered with
Fig, 4. Photomicrograph one month after grafting in the continuous group (Elastica Van Gieson, x 100). The thickness of the pannus is 107gm. The host vessel shows hyalinoid degeneration (Arrow). H: Host vessel, P: Prosthesis
50
H. Takenaka et al.: Sutureless Anastomosis was found, and the graft fiber was exposed. At the end of the 12th month, the intraluminal surface of the graft had become smooth and completely covered with endothelial cells (Fig. 11). Discussion
Fig. 5. Photomicrographs 6 and 12 months after grafting in the continuous group (Elastica Van Gieson, ×40). A (6 months) B (12 months) Hyalinoid degeneration can be seen (Arrows) platelets and a sparse fibrin net. Platelets were interconnected by dendrite spreading into branches. At the end of the 3rd month, the fibrin net had become dense, and the intraluminal surface of the graft was partly dense and partly rough. At the rough part of the intraluminal surface, no formation of the neointima
The basic manual technique to promote the healing of injuries is to adhere tissues together. For this purpose, the stitching together of tissues with a needle and thread has been used for a long time. Along with advances in surgery, improvements have been made in suturing techniques and materials, but stitching together with a needle, thread and ligation is stil! the basic technique. In the area of vascular surgery too, anastomosis with sutures is generally used, however, experience and skill is required in the anastomosis of small blood vessels, especially in a heparinized state, and thus, anastomotic procedures are not always safe and easy. What has the most influence on the strength of the anastomosed part in the long term after an operation is the density and volume of the newly formed adventitia in the anastomosed part. That is to say, in arterial reconstructions using a prosthesis, the required function of the sutures is simply to keep the host blood vessel and prosthesis fastened tightly together for a certain period. Therefore, the presence of suture threads for a long period of time is harmful, since these suture threads are likely to cause infection, inflammation and anastomotic neointimal hyperplasia. For this reason, we performed the present experiment so as to develop a technique for the sutureless anastomosis of blood vessels. At present, two methods are being used both experimentally and clinically for the sutureless anastomosis of
Fig. 6. Photomicrograph 12 months after grafting in the stay suture group (Elastica Van Gieson, ×10). Hyalinoid degeneration was found. (Arrow) H: Host vessel, P: Prosthesis
H. Takenaka et al.: Sutureless Anastomosis
Fig. 7. Photomicrographs in the sutureless group. A (One month Elastica Van Gieson, × 10): The pannus is 140 ~m. B (Three months Elastica Van Gieson, ×10): The pannus is 200~m. C (Twelve months Hematoxylin and eosin, ×10): The pannus has become 41 ~m, and there are neointimal cells present. H: Host vessel, P: Prosthesis, Arrows: Pannus blood vessels, one being the laser method and the other the adhesive method. The laser method is a comparatively new method, first used in 1970 by Jain et al. a in closing incised small vessels. Since Morris et al. 2 reported in 1980 on their actual application of a laser to the anastomosis of blood vessels, there have been many reports, however, no reports have been made yet about the grafting of prostheses using a laser. Though we tried to implant an e P T F E graft or a knitted Dacron graft using a CO2 laser, no adhesion was obtained at the anastomotic line. On the other hand, adhesives have been used for the successful anastomosis of blood vessels. Adhesives require properties such as sterility, quick yet strong adhesion, no toxicity, no foreign body reaction and the potential for use in the presence of some water. There are two adhesives which satisfy the above requirements: one is fibrin glue, and the other a cyanoacrylate adhesive.
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Fig. 8. Photomicrographs in the sutureless group (Elastica Van Gieson, × 100). A (One month): Inflammatory cellular infiltration can be observed. B (Twelve months): Inflammatory cellular infiltration is not seen. Arrows: cyanoacrylate adhesives
Fibrin glue is an adhesive which was developed based on the fact that in the healing process of injuries in the living body, fibrinogen solidifies to form fibrin nets, which have an adhesive action. There are many reports on the anastomosis of blood vessels with the use of fibrin glue. However, in the anastomosis of arteries, fibrin glue is used as an auxiliary in most cases after several stitches have been made for fixing the sutures. 3,4 In the anastomosis of blood vessels using fibrin glue, there are cases in which anastomosis was obtained successfully without leaving even a single piece of the sutures. 5'6 However, the adhesive action of the fibrin glue is very weak immediately after application, and therefore, it cannot be used in a high pressure area such as the arterial system. As for prosthesis, we tried to implant knitted Dacron grafts, human umbilical cord vein grafts ( H U C V G ) and e P T F E grafts. When using the knitted Dacron graft, the adhesive filtered out to the intraluminal surface of the graft and it is suspected of causing thrombosis. As for H U C V G , it was difficult to tightly fasten the host vessel and graft pulling 4 stay sutures. However, there
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H. Takenaka et al.: Sutureless Anastomosis
Fig. 9. Scanning electron micrographs in the continuous group A (One month, ×70): Suture threads are covered with a thin fibrous membrane. B (Twelve months, ×700): The anastomotic line is smooth were no such problems in using the ePTFE graft, and so we used this graft. Regarding the binding mechanism of the cyanoacrylate type adhesive, a cyanoacrylate monomer forms polymer chains in the presence of a small amount of water. It gains adhesion quickly, and its adhesive power is very strong, however, it has the drawback that when applied it hardens strongly and as a result, lacks elasticity. The alkyl-2-cyanoacrylates belongs to a class of vinyl monomer and its structural formula is represented as: CH2
JCN C"-COO - R
The alkyl side chain ( - R ) determines the speed of polymerization, flexibility, and toxicity. 17 The methyl compound (short chain) has high flexibility, but it is much too toxic to the host vessels and its polymerizing speed too slow. Contrary to this, the butyl compound (long chain) has less flexibility, less toxicity and a more
Fig. 10. Scanning electron micrographs in the stay suture group A (One month, xT0): The staying sutures (arrow) are exposed. B (Three months, x220): Newly formed intima has developed. C (Twelve months, x700): The anastomotic line is smooth
rapid polymerizing speed. Thus, we determined to use ethyl-2-cyanoacrylate monomer, which is an intermediate type compound. The application of cyanoacrylate adhesives to the medical field was started in about 1960. In the area of vascular surgery, in the early stages there were many reports on the direct closure or repair of arterial incisions. 7-9 Regarding applications to the anastomosis of blood vessels, all reports focused on the anastomosis of blood vessels in the living body. In addition, cyanoacrylate adhesives were used as an auxiliary after placing several stay sutures. 1°-12 When cyanoacrylate adhesives were used, the resulting complications were mainly bleeding in the early stages and aneurysmal dilatation in the later stages. 9 In our experiment, 7 animals out of 19 died in the sutureless group and of these 7, 5 died of massive bleeding which occurred immediately after removal of the aortic clamps. These 5 animals which died of bleeding were operated on during the early period in this experiment. The cause of
H. Takenaka et al.: Sutureless Anastomosis
Fig. 11. Scanning electron micrographs in the sutureless group A (One month, x1750): The intraluminal surface is covered with a rough fibrin net and the platelets. B (Three months, x450): The fibrin net has become dense. C (Twelve months, x450): The intraluminal surface is covered with neointimal cells
the massive bleeding was technical errors such as the insufficient application of adhesive or inadequate compression to the anastomotic part at the time of pulling away the stay sutures. There was no aneurysmal dilatation seen in any of the animals. It was considered necessary to apply the adhesive evenly around the anastomotic line, however, our impression was that when too much adhesive was applied, it simply hardened around the anastomosed part without sufficiently exhibiting its adhesive power in the anastomosis between the prosthesis and the host vessel. In this connection, it is reported to be a tendency that the thicker the layer the adhesive is the weaker the adhesive power becomes. 13 According to Tschopp, 12 it is important to apply just a small quantity to minimize the heat from polymerization and the chemical toxicity. When using cyanoacrylate adhesives, we too tried to apply the minimum amount necessary. There was no pseudo-
53 aneurysm seen in the anastomotic line and there were no decreases in the tensile strength of the anastomotic line even 12 months after grafting in our experiment. Concerning vital reactions to cyanoacrylate adhesives, Jacobson et al., 13 who applied cyanoacrylate adhesives to the anastomotic line of the blood vessels of mongrel adult dogs, reported the following results: After 12 hours, there were acute reactions, and after 72 hours, necrosis spread to the entire part of the media. On and after the 4th day, fibroblasts began to invade the necrotic part of the media, and after 3 months, the necrotic media had been completely replaced by fibrous tissue. After 6 months, both media and intima had become normal except for chronic inflammation around the sutures. Such toxicity of the adhesives is considered to be due to heat from polymerization, formaldehyde and alkyl cyanoacetate, which are decomposed products of the cyanoacrylate polymer. 12'14 In our experiment, inflammatory reactions around the anastomotic line, which were seen at the end of the 1st month, were not observed at the end of the 3rd month and later. Furthermore, the pannus in the anastomotic line after 12 months in the sutureless group was thinner than that in the continuous suture and stay suture groups and new endothelial cells were formed in the regular manner in the scanning electronmicrograph. Thus, cyanoacrylate adhesives did not produce any harmful effects on the healing of the anastomotic line in the long term. Moreover, according to examination by optical microscopes, hyalinoid degeneration was seen from the 1st month in the continuous suture and stay suture groups in the parts where sutures were present, but no such degeneration was observed in the sutureless group. There is a report 15 that such hyalinoid degeneration is due to ischemia caused by sutures present for a long time in the anastomotic line. In this respect, sutureless anastomosis using an adhesive is considered to be more advantageous than anastomosis with suture threads. However, cyanoacrylate adhesives have the following drawbacks: Firstly, the internal diameter of the blood vessels used in our experiment was 5 mm. The problem is whether cyanoacrylate adhesives can be used for blood vessels smaller than 5 mm in internal diameter. Cyanoacrylate adhesives cause necrosis in the adventitia and media, however, in comparatively large vessels of 3-5 mm in internal diameter, the toxicity is less likely to cause thrombus in the lumen. On the other hand, in smaller blood vessels with an internal diameter of 0.5-2 mm, inflammation spreads into the intima, causing hyperplasia of the intima, aneurysmal dilatation and thrombus. 7A6'17 Therefore, it is considered impossible to us6 cyanoacrylate adhesives for the sutureless anastomosis of blood vessels 2 mm or less in internal diameter. 18
54
Secondly, cyanoacrylate adhesives are not absorbed into the living body permanently. Cyanoacrylate adhesives remained on the adventitial side of the anastomosed part even after 12 months. It is desirable in the anastomosis of vessels to use adhesives which remain only for a short term until the adventitia becomes organized and eventually absorbed into the living body. Finally, the elasticity of the adhesion is poor in this cyanoacrylate adhesive, which brings about incompatibility with the blood vessels of the living body. It is feared that this incompatibility may lead to anastomotic neointimal hyperplasia. In our experiment, the patency rate in the sutureless group within 1-12 months after grafting was unsatisfactory, the value being 75.0 per cent. Obstructions were due to a thrombosed lumen caused by the adhesive which leaked into the lumen. In the sutureless anastomosis of blood vessels using an adhesive, it is most important that the prosthesis is tightly fastened to the host vessel so that the adhesive does not leak into the lumen. For this purpose, various techniques are being employed such as the overlapping of the host vessel with the prosthesis, the use of special devices such as the stent and ring, and so forth. 9'19 However, stenosis and deformation at the anastomotic line are unavoidable in each of these techniques. We applied the adhesive to the sutured line while pulling the stay sutures so that the host vessels and prosthesis could be fastened together tightly with each other. After that, the suture threads were removed. Since we did not put any foreign body into the anastomosed part, no deformation or stenosis occurred at the anastomotic line. Technically, the anastomosis could be easily performed, provided care was taken to fasten the prosthesis tightly to the host vessel at the cut end by evenly pulling the 4 stay sutures. At present, there are very few reports about the grafting of prostheses with the use of an adhesive. In our experiment, however, there were cases of patency even after one year. In addition, the pannus was equal to or smaller in thickness than that formed in animals sutured by a conventional continuous suture, or by stay sutures on 4 sites followed by the application of an adhesive. These results lead us to consider the fact that it would be possible to clinically apply this method of grafting with an adhesive. The sutureless anastomosis of blood vessels has been stopped over the past several years and yet, it has now been found that it is not impossible to perform a sutureless anastomosis if easyto-remove polypropylene sutures are used. It is hoped
H. Takenaka et al.: Sutureless Anastomosis
that in the future better manual techniques will be developed so that the adhesive will not leak into the lumen, and at the same time a more satisfactory adhesive will be made.
References 1. Jain KK, Gorisch W (1979) Repair of small blood vessels with the Neodymium YAG laser: A preliminary report. Surgery 85: 684-688 2. Morris JR, Carter M (1980) Laser-assisted microvascular anastomosis (LAMA). (abstr) Las Vegas: Orthopedic Research Society 3. Ikossi-O'Conner MG, Ambrus JL, Uma Rao (1983) The role of fibrin adhesive in vascular surgery. J Surg Oncol 23:151-15 4. Decleer W, Vanhove M, Coenen L, Boeckx W, Grunwez JA (1985) Fibrinous tissue glue in artery anastomosis. Physiological, histological and scanning evaluation. Acta chir belg 85:121-124 5. Brunner FX (1984) Histological findings in sutured and fibringlued microvascular anastomosis.Arch Otorhinolaryngol 240: 311-318 6. Gestring GF, Lerner R Requena R (1983) The sutureless microanastomosis. Vasc Surg 17:364-3. 7. Carton CA, Heifetz MD, Kessler LA (1962) Patching of intracranial internal carotid artery in man using a plastic adhesive (Eastman 910 adhesive). J Neurosurg 19:887-896 8. Nathan HS, Nachlas MM, Solomon RD, Halpern BD, Seligman AM (1960) Nonsuture closure of arterial incisions using a rapidlypolymerizing adhesive. Ann Surg 152:648-65 9. Carton CA, Kessler LA, Seidenberg B, Hurwitt ES (1961) Experimental studies in surgery of small blood vessels. J Neurosurg 18:188-194 10. Hosbein DJ, Blumenstock DA (1964) Anastomosis of small arteries using a tissue adhesive. Surg Gyn Obst 118:112-114 11. Hafner CD, Fogarty TJ, Cranley JJ (1963) Nonsuture anastomosis of small arteries using a tissue adhesive. Surg Gyn Obst 116:417-421 12. Tschopp HM (1975) Small artery anastomosis using a cuff of dura mater and a tissue adhesive. Plas and Reconstr Surg 55:606-611 13. Jacobson JH, Moody RA, Kusserow BK, Reich T, Wang MCH (1966) The tissue response to a plastic adhesive used in combination with microsurgical technique in reconstruction of small arteries. Surgery 60:379-385 14. Gottlob R, Blumel G (1967) The toxic action of alkylcyanoacrylate adhesives on vessels. J Surg Res 7:362-367 15. Naoe A (1989) The role of suture material on healing of vascular anastomosis. Nippon Geka Gakkai Zasshi (J Jpn Surg Soc) 90:941-948. (in Japanese with English Abst.) 16. Hoppenstein RH, Weissberg D, Goetz RH (1965) Fusiform dilatation and thrombosis of arteries following the application of methyl-2-cyanoacrylate (Eastman 910 monomer). J Neurosurg 23:556-564 17. Vinters HV, Galil KA, Lundie MJ, Kaufmann JCE (1985) The histotoxicity of cyanoacrylates. Neuroradiol 27:279-291 18. Weisberg D, Schwartz P, Goetz RH (1966) Nonsuture end-toside anastomosis of blood vessels. Surg Gyn Obst 123:341-346 19. Yamagata S (1982) Experimental studies of nonsuture microvascular anastomosis using soluble PVA tube and plastic adhesive. (in Japanese with English Abst.) Arch Jpn Chir 51:104117
