Of the FISTULA LACHRYMALIS.
THE Fistula Lachrymalis is generally understood to be such a Disorder of the Canals leading from the Eye to the Nose, as obstructs the natural Progress of the Tears, and makes them trickle down the Cheek: But this is only the first and mildest stage of the Disease; in the next, there is a Mucus resembling Matter, and afterwards Matter itself discharged with the Tears from the Puncta Lachrymalia, and sometimes from an Orifice broken thro' the Skin between the Nose and Angle of the Eye: The last and worst Degree of it is, when the Matter of the Abscess, by its long Continuance, has not only corroded the neighbouring soft Parts, but also affected the subjacent Bone.
For the better understanding the Seat and Nature of this Distemper, I have here annexed a Representation of the Lachrymal Ducts.
In treating of the Fistula Lachrymalis, most Writers mention the Inflammation and Ulceration of the Saccus, as being sometimes the immediate Causes of it; but then they all suppose, that the Tears becoming acrid and corrosive, excite the Inflammation and Abscess; though many of them imagine that the Tears themselves not finding a way thro' the Nasal Duct, do, from stagnating in the Saccus, corrupt and become the Matter discharged by the Puncta Lachrymalia; but the latter Opinion is most certainly ill-grounded; for besides that the Tears are not of a Composition to become Pus, it may be observed almost at any time upon pressing the Abscess, that the two Fluids appear unmixed; and with regard to the general Doctrine of the Sharpness of the Tears producing the Disorder, I think it is much to be questioned; since the Cornea and Tunica Conjunctiva being more sensible Membranes than the Saccus, would more readily be offended by them; but as we see they are not in the least injured, and every Part of an Animal Body is subject to Inflammation, &c. from internal Causes, I believe this external one may be justly doubted.
Whatever be the Cause of the Inflammation, whether the Small-pox, Lues Venerea, &c. the Effect of it is an Obstruction of the Ductus ad Nasum. That a total Obstruction should follow upon an Inflammation in so large a Vessel as the Nasal Duct, I presume is owing to its Situation in the bony Groove of the Os Unguis, Which not allowing it to dilate in its Inflammation and thickening, must necessarily make it fill up the whole Channel, and cause that Regurgitation of Tears and Matter, which is the constant Symptom of this Disease.
Some Years since, Monsieur Annell a French Surgeon, recommended in the recent Fistula, to pass a small Probe thro' one of the Puncta Lachrymalia into the Saccus and Nose, in order to break the Concretions which were supposed to make the Obstruction, and with a small Pipe and Syringe to throw an Injection thro' the other, in order to wash them away. This Method was at first received with great Applause, and still continues to be practised by some very eminent Surgeons; yet by what I have been able to learn from the Experiments of others, and the reason of the Thing, I am by no means inclined to think favourably of the Invention; for as the very Characteristic of this State of the Fistula, is the Reflux of the Tears from the Saccus, the Channels leading to it from the Puncta Lachrymalia must be supposed clear; and as to the Obstruction in the Nasal Duct; an lnjection thrown with so little Force, can hardly be imagined sufficient to remove it; and still less, if it be true that the Obstruction is not owing to any loose Substance clogging up the Passage, but to an Inflammation of the Membranes.
If then the Injection cannot assist by the Force of its Stream, the Advantage must arise from its balsamick Qualities; but no Surgeon at this time dilates an Abscess of any kind by Injections when the Pus is good-conditioned, and he can by Compress diminish the Cavity of it, as may be done in this very Case, and which should be practised before any other Method is undertaken: Indeed Annel and his Followers, after the Injection, applied a Compress and Bandage, to the good Effects of which, rather than any of the other Processes, I am inclined to think the Success was owing.
When the Quantity of Matter returned by the Puncta increases, notwithstanding the use of Compress, and the Tumour of the Saccus grows larger; it then becomes necessary to perform the Operation; the Design of which is to cure the Ulcer, and make way for the Tears into the Nose.
The general Notion that the Abcess of the Bag always occasions a Caries of the Os Unguis, perhaps may have led Surgeons into the Method of destroying both Saccus and Bone with a perforating Instrument, and afterwards more effectually with an actual Cautery, in order to remove the disordered Bone, and at the same time to make an artificial Canal into the Nose: But as there are many Instances of Cure by a mere Incison of the Saccus Lachrymalis, the rougher Method of Perforation ought not to be used, unless there is evidently a Caries in the adjacent Bone, or that after the Ulcer of the Saccus is healed, the Tears cannot be made to pass through the Duct; tho' even in that case, the Application of Fire is not only generally useless, but often proves hurtful, and defeats the very End it was intended to promote. The Design of the Cautery is to prevent the artificial Canal made by the Perforation from closing, but the Operators who recommend it, confess that in Persons who have been cauterised, even at the best, the Tears trickle down ever after; whereas that Accident does not so often attend on those where the Incision only is practised: The Reason of this Difference may perhaps be more clearly explained by a parallel Instance: If we divide a Vein quite thro', and cauterise its Extremities, 'tis well known that the Sloughs formed by the Fire hardly ever separate from the living Parts of the Vein, until they are totally closed up so as to prevent any Effusion of the circulating Blood; the Consequence of which is the breaking off the Communication of the divided Parts of the Vein; whereas if there was only an Opening made with a sharp Instrument, or even a Piece of the Vein carried away by it, the divided Parts would soon re-unite, and the Circulation be continued thro' them: for the same Reason, by the use of the Cautery, the Communication between the Puncta Lachrymalia and Saccus, will often be intirely destroyed; and the Perforation into the Nose, tho' it remain open, will of consequence not answer the Purpose for which it was intended.
It may perhaps be said, that by introducing the Cautery through a Canula, the upper part of the Saccus, or opening of the Lachrymal Channels, may be protected from these ill Effects. But I believe it will plainly appear, by the Rudeness of the Scar after the healing of the Wound, how powerfully Fire will work upon the neighbouring Parts, notwithstanding this Precaution.
From what has been said of the Nature this Disease, the use of fire must be discarded in all the Stages of it, and even Perforation for the most part be practised only when the subjacent Bone is carious; but this Cirumstance is very rare, and for my own part, since I have doubted its frequency, it has not been my fortune to meet with a single Instance of it, tho' I have had Fistulas of many Years standing under my Care, in some of which, the Pus had found issue, thro' the Bag and Skin, and formed an external Ulcer likewise. The Reason why the inferior part of the Saccus is not so often corroded as the superior (in which case the Bone would necessarily be affected) is, that here, as in every other part of the Body, Abscesses will break where they are least under Confinement, as in those Places they sooner give way to the preternatural Influx of the juices, and in consequence becoming weaker, will sooner be destroyed. Since therefore, neither the long continuance of the Disease, nor the great Discharge of Matter, are positive Symptoms of a Caries; we ought to be well satisfied of it by the Feel of the Probe before we perforate; but if upon opening the Bag, or in the course of the Dressing, it appears the Os Unguis is bare, we are not to wait for an Exfoliation, the Bone being so very thin, but to break thro' with a small Perforator.
Many Writers mention the Success of having sometimes treated the Fistula Lachrymalis as a mere Abscess of the Saccus, though in general they recommend the use of Fire; but when the Abscess is so foul as not to cure by Incision, a piece of the Bag itself must be cut away; and thus Celsus treated the Fistula Lachrymalis (tho' he also used the Cautery) without perforating.
The Manner of operating in those Cases where Perforation is not required, is this: Supposing the Abscess not broken, choose a time when it is most turgid with Matter and to this end, you may shut the Patient's Eye the Day before, and lay little Slips of Plaister upon one another across the Lids, from about the Puncta Lachrymalia to the internal Angle; which compressing their Channels, and preventing the Flux of the Matter that way, will heap it up in the Bag, and indicate more certainly the Place to be cut. If the Abscess is already open, the Orifice and Probe will inform you where to enlarge: Then placing the Patient in a Seat of convenient height for the Management of your Hand; with a small Incision-knife dilate from the upper part of the Bag, down to the Edge of the Orbit, without any regard to the Tendon of the Orbicularis Muscle, or fear of wounding the Blood-Vessels; tho' if you see the Vessels, 'tis proper to shun them: The Length of this Incision, will be near four tenths of an Inch. It has been advised in opening the Bag, to introduce a small Probe thro' one of the Puncta into its Cavity, to prevent wounding the posterior Part of it; but I think this excess of care may be more troublesome than useful; since in so large a Vessel, a very small share of Dexterity is sufficient to avoid the mistake: In making this Incision, care must be had, not to cut too near the joining of the Eyelids, because of the Deformity of the succeeding Scar: tho' the blear Eye or uneven Contraction of the Skin in that Part, after the Operation, is generally owing to the use of the Cautery, and not to the Wound of the Tendon of the Orbicularis Muscle; for this last, is necessarily from its situation always cut through, but without any Inconvenience, because of the firm Cicatrix afterwards that fixes it strongly to the Bone.
When the Bag is open, it is to be filled with dry Lint, which the next Day may be removed,. and exchanged for a Dossil dipt in a soft digestive Medicine: This must be repeated every Day once or twice, according to the quantity of the Discharge; now and then, when the Matter is not good, using the Precipitate Medicine, and from time to time, a Sponge-Tent, to prevent the too sudden reunion of the upper part of the Abscess. When the Discharge begins to lessen, it will be proper to pass a small Probe, a small Bougie, or Silver Wire through the Nasal Duct into the Nose, every time it is drest, in order to dilate it a little, and make way for the Tears and Matter which by their Drain will continue to keep it open. This Method must be followed 'till the Discharge is nearly over (which will be in a few Weeks) and then dressing superficially with dry Lint, or any drying Application, the Wound will seldom fail of healing. After the Cure, in order to prevent a Relapse, it will be proper, for a few Weeks, to wear the compressing Instrument represented in the Copper-plate.
When the Bone is bare, and the Fistula requires Perforation, the Perforator is not to be carried down the Ductus ad Nasum, for fear of boring into the Sinus Maxillaris; but more internally towards the Nose, which will bleed freely, if properly wounded: The Wound afterwards should be dressed with Dossils, in the manner above described, and the Probe or Silver Wire be every Day passed through the Ductus ad Nasum, left after the Care of the Abscess, it should still remain obstructed; and if upon trial, the Duct should be so filled up as not to admit the Wire, it will be right to keep open the Perforation into the Nose, with a small Tent, 'till the Discharge is almost quite ceased.
I shall finish this Chapter with observing, that though a weeping Eye will sometimes remain after the Treatment of the Fistula Lachrymalis, yet the Inconvenience of it is so small, compared with a Discharge of Matter, that it would be happy if this were the worst Consequence of the Operation; but it sometimes happens, that the Ulcer when healed, breaks out again, and sometimes too, that it cannot be quite healed, by reason of the inferior part of the Saccus and Nasal Duct lying so deep below the edge of the Orbit, which makes the proper application of Dressings to the bottom of the Ulcer more difficult: T'is this situation of the Saccus, that in a great measure prevents any good effects from burning and perforating, if the Perforation only be dressed, as is very much practised, since the Dressing will be full four tenths of an Inch above the lowest part of the Ulcer.
With regard to the trickling of the Tears, though generally speaking, it is prevented by the Method I have recommended; yet it does not appear at all wonderful, it should so frequently be the consequence of the others, when we consider how much at best the Saccus contracts after a great deal of it has been destroyed; and how possible it is for the Wound to fill up with Granulations of Flesh, which cannot fail to prove an Obstacle to their Passage into the Nose.
A. The Eye, with the Skin of the Eyelids, denuded, in order to shew the Orbicularis Muscle: The white streak running from the inner Angle of the Eye toward the Nose is called the Tendon of the Orbicularis Muscle, though I think it rather a small Ligament. At a little distance from the internal Angle, on the edge of the Eyelids may be observed two black Spots, Which are the Orifices of the Lachrymal Channels, and called the Puncta Lachrymalia.
B. The exact Dimension of the Lachrymal Channels and Bag; the pricked Line represents the edge of the Orbit. I have here taken care to shew the oblique Direction of the Bag as it runs from the Nose towards the Orbit.
From comparing this Figure, with the Situation of the Puncta Lachrymalia in the Foregoing one, it will appear that only the Upper part of the Bag lies under the Tendon of the Orbicularis Muscle, and consequently is the only part wounded and burnt through in the common Operation, when the Perforator is carried horizontally From the Angle into the Nose, as is generally practised. And I believe the size of the Bag here represented, though not so large as when it is diseased, will, at once shew the Propriety of opening it first by an Incision down to the Orbit, or even farther, and then treating the Fistula with the same Dressings as we do other fistulous Ulcers.
C. A small Incision-knife, more handy than a larger for opening the Bag.
D. The Perforator to destroy the Os Unguis, if ever it should happen to be necessary.
E. An iron Instrument made thin and pliable, to set even on the Forehead, and for use covered with Velvet; the Holes at the three Extremities receive two pieces of Ribband, by which it is fastened on the Forehead: The Button at the end of theScrew is to be placed on the Saccus Lachrymalis, and the Screw to be twisted till the Button makes a considerable Pressure on the Bag: The Button should be covered with Velvet, and a little Compress of Plaister be laid on the Bag before it is applied, to prevent the Skin from being galled by the Pressure. The little branch of Iron which receives the Screw, must be soft enough to admit of bending, otherwise it will be difficult to place the Button exactly on the Bag. This Instrument is for the left Eye only; it should be worn Night and Day in the beginning of a Fistula, and after a Fistula has been healed by Incision; but as the Success depends upon the exact Situation of the Button upon the Bag, it should be carefully looked after.