Canad. Med. Ass. J.Oct. 10, 1964, vol. 91 ZINGG AND KHODADADEH: VASCULAR ANASTOMOSIS 791

ABSTRACT

Different vascular suturing techniques wereassessed in the experimental laboratory.Staples made of tantulum wire were em-ployed for vascular anastomoses in normaldogs' arteries and veins and in atheroscler-otic rabbits' aortas. The staples were drivenwith the NRC Vascular Suturing Instru-ment. In a similar series of experiments aplastic bonding agent (Eastman 910) wasused. The anastomosed vessels were foundto be patent and few complications wereencountered. However, it is unlikely thatthe conventional suture technique with thecurrently available materials will be re-placed by these methods except underspecial circumstances. Clinical applicationof the stapling method is envisaged in theanastomosis of small vessels and in situa-tions when speed is essential, whereas thebonding agent promises to be useful as anancillary method in combination withsutures or staples.

SOMMAIRE

Diverses techniques de suture de vaisseauxont . mises it l'.preuve en laboratoire.Des crampons faits de fil de tantale ontservi it r.aliser des anastomoses sur desart.res et des veines normales chez le chienet sur des aortes ath&oschirotiques de lapin.Les crampons ont .t6 poses avec l'instru-ment NRC it sutures vasculaires. Au coursd'une autre s6rie d.exp6riences du m.megenre, une substance plastique adhesive(Eastman 910) a . employ6. Les anas-tomoses vasculaires .taient .tanches et ilne survient que peu de complications. Iiest cependant peu probable que Ia techni-que classique de suture vasculaire, avecles fils dont on se sert actuellement, soitremplac.e par ces m.thodes nouvelles saufdans des cas particuliers. On pr.conised'employer les crampons pour anastomoserles petits vaisseaux et dans les cas oii lavitesse est un facteur essentiel. Les sub-stances adh6sives seraient utiles commecompkment des sutures au fil ou auxcrampons.

792 ZINGG AND KHODADADEH: VASCULAR ANASTOMOS]

structures, as in the introduction of polyethylenecatheters into arteries, veins, lymphatic vessels orbile ducts of rats weighing 200 to 300 g. Exceptfor the execution of very simple movements, suchas cutting a nerve which is hardly visible to thenaked eye, magnifying devices were not found tobe very useful in the laboratory. The limiting factorin carrying out free movements on a small scaleis the tremor of the hand and fingers, not the limi-tations of eyesight.

It is realized that these may well represent areasof individual differences and that other surgeonsmay find certain techniques of microsurgery to beuseful. It appears, however, that this method is notattracting as much attention as it did a few yearsago.

Tm. TECHNIQUE OF VASCTJLAR ANAsToMosI.WITH STAPLESThe use of metal staples for vascular anastomosis

requires a mechanical device to drive the staples.The idea is quite old but adequate instrumentswere not designed until recently.4 A Russian instru-ment appeared a few years ago, but the procedureinvolved in its use was rather complicated. Otherinstruments have been designed in the U.S.A.5'6Our own experience is limited to the NRC stapler,the instrument designed and initially constructedin the National Research Council Laboratories inOttawa.7'8 The staples are made of 0.005" tantalumwire; the length of the legs is 0.045". The staplesare inserted into slots in the driver bushings whichconsist of two halves in order to allow their appli-cation to the blood vessels (Fig. 1). The two halvesare in turn inserted into the handles of the suturinginstrument. Symmetrical anvil bushings are insertedinto the other handles and applied around theartery. The open ends of the artery are then evertedover the driver bushing and over the anvil bushingby means of a special instrument and held in placewith a rubber ring (Fig. 2a and 2b). The twopairs of handles are then joined together andlocked. Thus the driver bushing is pressed against

ANVIL RECESS

STAPLE

PUSHERN.

Canad. Med. Ass. 3.Oct. 10, 1964, vol. 91

Fig. 2a

Fig. 2bFig. 2.-Vascular suturing instrument. Diagrammatic rep-

resentation of bushing arrangement for stapling operation:(a)cuffs everted, bushings approximated; (b) staples driven.

the anvil bushing with the two layers of the vesselwall in between. Hemostatic clamps which hadbeen applied initially can then be attached to theinstrument on either side and the staples can bedriven by moving a lever system. After the anasto-mosis is completed, the rubber rings are removed,the hemostatic clamps are removed from the instru-ment but remain on the blood vessel, the evertedends of the vessel are lifted off the bushings whichare removed next, the everted portions of thearterial wall are arranged as a cuff over the staplesand the clamps are removed.Although the method is comparatively simple,

the instrument is not an easy one to use, becauseit requires considerable experience and trainedassistance. The greatest drawback appears to bethe necessity of isolating the vessels for almost one-half inch on either side of the anastomosis. Furtherrefinement and improvements will almost certainlybe forthcoming.The experimental evaluation of this technique is

still in progress in this laboratory. At the presenttime more than 100 anastomoses have been done,without a failure which could not be explained onthe basis of inexperience of the surgeon or theassistant. Bleeding from small leaks stops whenpressure is applied.Anastomoses have been performed on the dog's

femoral artery and vein and also on the splenicartery and vein. In another project the rabbit's

Canad. Med. Ass. J.Oct. 10, 1964, vol. 91 ZINCG AND KHODADADEH VAscuI. ANASTOMOSIS 793

The process of polymerization should not bestrongly exothermic, because the polymerizationmust take place in viva.

Catalysts which might be employed should notbe toxic because traces may still be present in thepolymerized end-product.The carcinogenic potential of these plastic ma-

terials must not exceed that of other foreignmaterials.Of the many thousands of plastic compounds

available, only a few satisfy the above-mentionedcriteria. In this laboratory a polyurethane'0 and anepoxy resin" were used in orthopedic surgery, anda methacrylate compound (Eastman 910) in vascu-lar surgery.

Several experimental studies were carried out.The best results were obtained by using patchesof Mersilene polyester fibre (polyethylene tereph-thalate) or of autogenous fascia that werebonded over arterial incisions or arterial defects.9It was possible to use the bonding agents onatherosclerotic aortas. In several instances, delayedhemorrhage was associated with gross infection ofthe wound. No foreign-body reaction could bedemonstrated in the histological slides.

Eventually, more elaborate animal experimentswill lead to a better definition of the indications forthe use of bonding agents. We realize that the workwith Eastman 910 was done with a rather crudetechnique, and further progress will depend-among other things-on the development of appro-priate instruments for positioning the vessel ends,such as that described by Healey.'2 The followingassessment of the clinical application of thesemethods therefore should not be considered final.

DIscussIoNRegarding these two methods of vascular anas-

tomosis, stapling and bonding with a "glue", whatare the relative merits and what are their respec-tive places in vascular surgery? Obviously the con-ventional suturing technique will not be replacedby any other method except in exceptional circum-stances. The stapler has a definite place in theanastomosis of small vessels, and when speed isimportant.The stapling instrument described herein is

suitable for vessels measuring 2-5 mm. in diameter.Carroll,'3 in a recent report of work in dogs,described the performance of anastomoses of theinternal mammary artery to the circumflex coronaryartery in less than two minutes. This cannot beaccomplished by suturing. Another model of thesame stapling device has recently been constructedfor use on vessels measuring 1 to 2 mm. in diameter.Beattie et al.'4 reported the successful transplant2-tion of a segment of the dog's bowel into the neckto bridge a defect in the esophagus. The arterysupplying the bowel was anastomosed to thesuperior thyroid artery, and the vein to the anteriorfacial vein by means of staples-another operation

794 ZINGG AND KHODADADEH: VASCULAR ANASTOMOSIS Canad. Med. Ass. J.91

which is difficult to carry out by conventionalmeans.The place of the bonding agent in vascular

surgery is more difficult to define. At the presenttime it appears that its main use will be as amethod ancillary to sutures and to stapling. Fre-quently the last stitch placed to stop a leak at thesuture line constricts the anastomosis and may beresponsible for its failure; here, the use of gluemay be preferable. A similar situation may arisefollowing a stapling procedure, and again a dropof glue may be better than a reinforcing stitch. Ourexperience has shown that bonding by means ofsynthetic materials fails in the presence of grossinfection. Unfortunately, therefore, the methoddoes not promise success in cases of secondaryhemorrhage due to infection.

SUMMARY

Experience with the NRC stapler and with abonding agent in the surgical anastomosis of bloodvessels has been outlined. The results have beenassessed in the light of future clinical applications ofthese methods. It is anticipated that they will find aplace in the surgical techniques of vascular anastomosis.

The loan of the vascular suturing instrument, arrangedby the National Research Council, Canadian Patents andDevelopments Limited, and the Medical Research Council,is gratefully acknowledged. The authors are indebted toMr. C. M. Hovey, Chief Engineer, Bristol Aero-IndustriesLtd., Winnipeg, Manitoba, for his advice in the field ofplastic materials; to Mr. R. J. Semple, Ethicon Inc., Somer-ville, N.J., U.S.A., for making the bonding agent availableand taking a personal interest in our work; to Mr. S. H. G.Connock, Head, Instruments and Control Systems Labora-tory, National Research Laboratories; and to Dr. W. G.Waddell, who taught the senior author to use the staplinginstrument, and to Professor C. C. Ferguson for his en-couragement while these studies were in progress. Figs.1 and 2a and 2b are reproduced with the permission ofthe National Research Council of Canada.

REFERENCES

1. JACoBSON, J. H., 2nd AND SL'AREZ, E. L.: Surg. Forum, 11:243. 1960.

2. SUAREE, E. L. AND JACOBSON, J. H.. 2nd: Ibid., 12:256, 1961.

3. CHASE, M. D. AND SCHWARTZ, S. I.: Ibid., 13: 220, 1962.4. Editorial: Lancet, 2: 27, 1963.5. MACDONALD, G. L., JR., TosE, L. AND DETERLING, R. A.,

JR.: Surg. Forum, 13: 88, 1962.6. COOPER, P. AND CHRISTIE, S. G.: Trans. N.Y. Acad. ,Sci.,

25: 365. 1963.7. VOGELFANGER, I. J. AND BEATTIE, W. G.: Canad. .1. Surg.,

1: 262, 1958.8. VOGELFANGER, I. J. et al.: surgery, 52: 354, 1962.9. KHODADADEH, M. et al.: Ibid., In press.

10. HOLLENBERO, C. et al.: Canad. J. Surg., 6: 371, 1963.11. JOWSEY, J. W., HOLLENBERO, C. AND ZINGG, W.: Un-

published results.12. HEALEY, J. E., JR. et al.: Surgery, 51: 452, 1962.13. CARROLL, S. E.: Canad. J. Surg., 4: 463, 1964.14. BEATTIE, W. G. et al.: Ibid., In press.

PAGES OUT OF THE PAST: FROM THE JOURNAL OF FIFTY YEARS AGO

PAROXYSMAL TACHYCARDIA

The symptoms characteristic of paroxysmal tachycardiaare becoming more and more frequently recognized andthose phenomena hitherto rarely described are now classifiedand given their proper place among the disturbances ofcardiac function, to a better knowledge of which experi-mental and clinical observations are continually contribut-ing.The onset is attributable to a variety of causes-emotion,

posture, stooping, an effort in an unusual position, e.g.,carrying ice and lifting it into a refrigerator, overeating,"hacking" to clear the throat, as described in one of Dr.Moffat's case reports.

Such causes are effective, however, only under abnonnalconditions of the heart muscle or of the cardiac nerves.Impulses of extrinsic origin arising from a single siteoriginate the attack and, setting the pace, control for ashorter or longer period the cardiac rhythm. Lewis main-tains that the first paroxysmal beat is premature and thatin the offset there is a characteristic "post-paroxysmal"pause. The pathology of this comparatively rare conditionis not yet made out. Experimentally such a regular rapidrate may be induced in hearts by repeated rapid faradiza-tion (Hirschfelder) or by tying the descending branch ofthe coronary artery (Lewis).

Isolated premature contractions occur, explained from thepoint of view of pathological or heterogenetic impulses.From this to repeated impulses from the same foci isanother step, and should several extrinsic foci become activethe heart responds irregularly to pathological impulses, andfibrillation is the condition described. There seems butlittle doubt that premature heart beats are determined byan irritable cardiac muscle-a weak muscle, or an over-worked muscle, or a muscle under the influence of somepoison. It is highly probable too that several factors maybe active in bringing about this result.

In most instances the theory of altered nutrition of theheart muscle is called upon to explain the alteration ofrhythm. On the other hand is it possible that in paroxysmaltachycardia a sensitization of the tissues in the cardiacmechanism takes place in a manner similar to that account-ing for asthmatic seizures,-an anaphylaxis under anotherform-the recurrences in part by reason of the disturbancesin circulation inducing the condition of myocardial de-generation, dilatation and death? Or again, is the causeto be found iii a poison produced under certain conditionsin the body which, acting directly upon the heart musclelike poisonous doses of aconite, induces such great accelera-tion and eventually fibrillation and death? With the increaseof our knowledge of physiological chemistry, disturbancesof metabolism are regarded more and more as accountablefor disturbances of function. Epilepsy, tetany, spasmophiliamay be mentioned as illustrations of diseases closely relatedwith intervals of practically a normal condition. These threediseases are marked by suddenness of onset, spasms andviolent motor disturbances. It would seem possible that anatural or induced irritability of the cardiac muscle mayrespond to the action of certain toxic substances so that thephenomena of paroxysmal tachycardia are induced.TREATMENT.-The treatment of this condition must

remain unsettled until chance discovers a remedy or re-search directs the measures of relief based upon a knowl-edge of the underlying causes now not understood. Attacksmay be cut short by pressure upon the vagus nerve of theneck, by the application of cold to the chest, by pressureover the pnecordium (Thome), by the use of digitalin orstrophanthin, or bleeding may afford relief in those caseswhere dilatation is advanced. Again, under apparentlyidentical conditions in the same or other patients theseagents are useless. To control restlessness and relieve thedistress morphine is often essential.-W. F. Hamilton,Caned. Med. Ass. 1., 4: 865, 1914.