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Anatomic surgery for salivary calculi
Operativeoral surgery
Anatomic surgery for salivary calculi Part II. Calculi
in the anterior
part
of the submandibubr
duct
G. R. Seward, M.D.S., P.D.S.R.C.S., M.B., B.S., London, England THE
LONDON
HOSPITAL
MEDICAL
COLLEGE
T
he presence of a calculus in the duct of a salivary gland is a common cause of swelling of the gland. Because in many instances the calculus is palpable beneath the mucosa of the mouth or is easily seen in a radiograph, there is a temptation to undertake the removal of such calculi without much thought concerning possible surgical difficulties. A bold incision is made over the calculns, and frequently the operator is lucky and the calculus is discovered and removed. In a significant number of cases, however, the outcome is not so satisfactory; either the calculus is not found or some important structure near the duct is damaged. A deliberate operative procedure involving identification of the major anatomic features is therefore advocated for these cases. PREOPERATIVE
ASSESSMENT
Calculi may be found anteriorly in the submandibular duct, posteriorly in the extraglandular part of the duct, or in the intraglandular part of the main duct. Anterior calculi are those which lie anterior to a line joining the mesial surfaces of the second molars. The preoperative assessment of anterior calculi depends upon the history, clinical examination, and plain radiography. A sialogram is not normally made preoperatively, as the injection of dye might dislodge the calculus and carry it into the posterior part of the duct. Because it is relatively easy to find an anterior calculus by inspection, palpation, or radiography, few such calculi are overlooked as a cause of symptoms. Thus, firm, chronically enlarged, and tethered glands which are the seat of chronic infection are uncommon with anterior calculi; although the submandibular salivary gland may be enlarged, it is usually soft and mobile. Normally, therefore, it is satisfactory to remove anterior calculi without a sialogram and
287
288
Seward
O.S., 0-M. & O.P. March, 1968
without considering removal of the submandibular gland. When the calculus is unusually large, however, or when the physical signs suggest, a damaged gland, a postoperative sialogram should be obtained in order to investigate the state of the gland. Some 3 to 6 months should be allowed to elapse after the calculus has been removed before this investigation is undertaken. It is unwise to attempt a sialographic procedure at an earlier date, as there is danger of introducing the contrast medium into the floor of the mouth through the healing incision in the duct wall. Also, unless the gland is given a chance to recover from the long period of obstruction produced by the calculus, a potentially useful organ could be condemned and needlessly removed. Should the gland be acutely infected when the patient is first seen, the immediate surgical removal of the calculus is contraindicated, as there is danger that the infection will spread into the floor of the mouth through the incision in the duct-unless, of course, as occasionally happens, it appears that a simple snip with a pair of sharp-pointed scissors will enlarge the duct orifice sufficiently to permit the stone to escape. After any infective episode ample time should be allowed for the inflammation in the tissues around the calculus to subside. Brisk bleeding from inflamed tissues can make the removal of salivary calculi unnecessarily difficult. Once the inflammation has resolved, it is usually possible to palpate a calculus in the anterior part of the duct, especially if the fingers of the other hand elevate the floor of the mouth by pressure applied to the submental region. Quite small calculi may be detected in this manner, even though they do not produce a palpable, hard lump but merely cause a thickening of the duct or give the papilla an unusual firmness. The larger calculi will be seen as yellowish masseselevating the floor of the mouth. A minute calculus which lies in the papilla or just behind it may also be seen, but only as a yellowish discoloration shining through the thin overlying tissues, Because the opening of the submandibular duct is small, it is uncommon
Fig. 7. A calculus ulcerating through the right submandibular the papilla. This is frequently mistaken for a calculus presenting
duct about 3 mm. behind at the papillary opening.
Volume 25 Number 3
Anatomic
surgery
for salivary
calculi
289
for even tiny calculi to peep through the orifice; sometimes, however, the mucosa ulcerates over the stone, and then one end will extend into the mouth (Fig. 7). A central true occlusal radiograph is used to demonstrate anterior calculi, as most of them are radiopaque. However, care should be taken not to overexpose the film, and it is recommended that one use about three fourths the exposure that is usually employed when the same view is used to demonstrate the mandible. In order to see small calculi, the illumination of the viewing screen must be particularly bright, but it should be well masked to avoid glare. Whenever an anterior calculus is discovered, it is a wise precaution to take a posterior oblique occlusal radiograph in order to study the posterior part of the duct and the gland, as it is not unusual to find one or more smaller calculi farther back. OPERATIVE PROCEDURE Patients rarely retch or resist the pressure of retractors during operative manipulations in the anterior part of the floor of the mouth. Indeed, the patient can consciously help by positioning the lips and tongue in a way that improves access to the surgical field. Hence, a local anesthetic is preferred. It is advisable to follow a set routine, for in this way complications are either avoided or surmounted without difficulty. The anesthetization of the tissues is started by a lingual block injection in the retromolar region. It is better to start in this manner because, if the floor of the mouth is infiltrated at the beginning, the injection might dislodge a small calculus which would then roll down into the intraglandular part of the duct. Since the duct may be dilated behind the calculus, even calculi which are larger than the diameter of a normal duct can be dislodged in this way. When anesthesia has been achieved, a suture is passed into the floor of t,he mouth and around the duct posterior to the stone. Once this has been done, there is no longer danger of the stone rolling backward. The duct inclines down to the gland at a moderate angle, so the suture must include a sizable amount of tissue if it is to embrace the duct. The easiest way to achieve this is to insert one suture into the floor of the mouth to a reasonable depth, and then to tent the tissues up with it while a second suture is inserted to pass below the duct (Fig. 8). An error that is frequently made is to place the suture too far laterally, so that it embraces the sublingual gland rather than the submandibular duct. Another error is to insert the needle too far medially, so that the sublingual veins are punctured. This may produce a hematoma which will make the subsequent dissection more difficult. The duct is found bisecting the angle formed by the sublingual plica and the line of attachment of the tongue. It is not necessary to tie the stitch tightly in order to trap the calculus; indeed, if it is tied tightly, the soft tissues of the floor of the mouth can be damage,d. It is sufficient to tighten a single knot until it rests on the floor of the mouth. Then the threads can be passed over the t,eeth and a pair of artery forceps clamped on the end so that their weight will pull the tissues up, kinking the duct. At this stage the floor of the mouth should be infiltrated with a local anesthetic and Adrenalin solution, and once more the sublingual veins must be avoided. Suf-
290 Seward
023, O.M. & O.P. March, 1968
Fig. 8
Fig. 9
Pig. 8. A suture has been passed around the submandibular duct posteriorly by the method illustrated in the inset photograph. An additional suture has been passed beneath the papilla. The floor of the mouth has been infiltrated with a vasoconstrictor, and an incision has been made over the duct. Fig. 9. The duct has been isolated and College tweezers have been passed under it to draw a thread through beneath the duct. The edges of the incision are retracted by sutures, and the sublingual veins appears as a lobulated swelling on the lingual side of the duct.
ficient solution should be injected around the duct to reduce bleeding. A further infiltration is made into the floor of the mouth on the other side, close to the lingual frenum, and a second suture is placed between the submandibular duct papilla and the frenum (Fig. 8). Gentle traction on the two sutures will steady the operation area and will make the mucosa sufficiently taut so that it can be readily cut with the scalpel. An incision is made along the line of the duct and over the stone (Fig. 8). If the calculus is neither visible nor palpable as a guide to the position of the duct, the incision is made along a line which bisects the angle between the root of the tongue and the sublingual plica. Although the knife should not be plunged deeply into the tissues, it should divide the mucous membrane and enter a little way into the underlying connective tissue.
Volume 25 Number 3
Anatomic surgery for salivary
calculi
291
Fig . 10
Fig
Fig. IO. Whi le the duet is steadied by the stay suture an incision is made over the (:alc.UlUS. Fig. 21. The calculus can be picked out of the wound with College tweezers.
ZGg. 1.9. Two sutures are sticient
to close the wound in the floor of the mouth.
0.X., O.M. & O.P. March, 1968
292 Seward
.
Pig. 13. A, The duct has been steadied by a stay suture and a longitudinal incision made over a sizable calculus. The calculus is adherent, however, and a stay suture has been passed through one edge of the incision in the duct so that the calculus can be freed from the duct wall. B, The calculus has been separated from the duct wall and is ready to be lifted out.
By a combination of blunt and sharp dissection with fine, sharp-pointed scissors, the wound is deepened toward the submandibular duct through the loose connective tissue, keeping lateral to the sublingual veins (Fig. 9). Once again, it is preferable to avoid puncturing the veins; should one be cut, however, the bleeding point is ligated with 5-O catgut. The submandibular duct may be identified by its pale, grayish color and by the network of fine capillaries which course over its surface. The duct is gently mobilized, and a stay suture is passed under it with a pair of College tweezers. The fine, curved, pointed tips of the tweezers can be pushed through below the duct, which is raised out of the wound across their blades (Fig. 9). A length of suture material is grasped in the tweezers and pulled through under the duct. If a pair of artery forceps is hung on the end of the stay suture, the operator will have control over the duct during the remaining manipulations. Frequently at this stage the calculus will be seen through the duct wall, and a longitudinal incision will release it (Figs. 10 and 11). If the calculus is a large one it may be adherent to the inside of the duct and, although the incision will expose it, some effort may be needed to free it from the duct wall. Yet another stay suture is inserted into one lip of the incision in the duct so that the operator can separate the calculus by blunt dissection without its bobbing about in a disconcerting fashion (Fig. 13). If the location of the calculus is not indicated by either a swelling of the duct wall or a yellowish discoloration, then the duct should be incised in what is judged from the radiographs to be its position. Should it be necessary, the incision may be extended a little way along the duct with a pair of fine scissors.
Volume 25 Number 3
Anatomic surgery for salivary calculi
293
If the calculus has not been located after this maneuvre, the duct should be milked to squeezeit toward the opening. Once the calculus has been taken out, the ligature that occludes the duct posterior to the surgical area is cut and removed. Milky white, mutinous saliva which has collected behind the stone will flood through the opening in the duct wall. The gland should be gently squeezed between one finger applied to the floor of the mouth over the upper pole and the fingers of the opposite hand npplied to the lower pole. Additional saliva will be discharged, and with it may appear minute calculi not seen in the radiographs. Finally, a pair of mosquito forceps is introduced into the duct to explore the posterior part for unsuspected calculi. To close the wound, all remaining stay sutures are removed and a few interrupted stitches are inserted to approximate the mucous membrane (Fig. 12). The incision in the duct itself is not sutured lest a stricture be created. Provided the duct is patent distal to the incision, no fistula will form.
Anatomic surgery for salivary calculi Part II. Calculi
in the anterior
part
of the submandibubr
duct
G. R. Seward, M.D.S., P.D.S.R.C.S., M.B., B.S., London, England THE
LONDON
HOSPITAL
MEDICAL
COLLEGE
T
he presence of a calculus in the duct of a salivary gland is a common cause of swelling of the gland. Because in many instances the calculus is palpable beneath the mucosa of the mouth or is easily seen in a radiograph, there is a temptation to undertake the removal of such calculi without much thought concerning possible surgical difficulties. A bold incision is made over the calculns, and frequently the operator is lucky and the calculus is discovered and removed. In a significant number of cases, however, the outcome is not so satisfactory; either the calculus is not found or some important structure near the duct is damaged. A deliberate operative procedure involving identification of the major anatomic features is therefore advocated for these cases. PREOPERATIVE
ASSESSMENT
Calculi may be found anteriorly in the submandibular duct, posteriorly in the extraglandular part of the duct, or in the intraglandular part of the main duct. Anterior calculi are those which lie anterior to a line joining the mesial surfaces of the second molars. The preoperative assessment of anterior calculi depends upon the history, clinical examination, and plain radiography. A sialogram is not normally made preoperatively, as the injection of dye might dislodge the calculus and carry it into the posterior part of the duct. Because it is relatively easy to find an anterior calculus by inspection, palpation, or radiography, few such calculi are overlooked as a cause of symptoms. Thus, firm, chronically enlarged, and tethered glands which are the seat of chronic infection are uncommon with anterior calculi; although the submandibular salivary gland may be enlarged, it is usually soft and mobile. Normally, therefore, it is satisfactory to remove anterior calculi without a sialogram and
287
288
Seward
O.S., 0-M. & O.P. March, 1968
without considering removal of the submandibular gland. When the calculus is unusually large, however, or when the physical signs suggest, a damaged gland, a postoperative sialogram should be obtained in order to investigate the state of the gland. Some 3 to 6 months should be allowed to elapse after the calculus has been removed before this investigation is undertaken. It is unwise to attempt a sialographic procedure at an earlier date, as there is danger of introducing the contrast medium into the floor of the mouth through the healing incision in the duct wall. Also, unless the gland is given a chance to recover from the long period of obstruction produced by the calculus, a potentially useful organ could be condemned and needlessly removed. Should the gland be acutely infected when the patient is first seen, the immediate surgical removal of the calculus is contraindicated, as there is danger that the infection will spread into the floor of the mouth through the incision in the duct-unless, of course, as occasionally happens, it appears that a simple snip with a pair of sharp-pointed scissors will enlarge the duct orifice sufficiently to permit the stone to escape. After any infective episode ample time should be allowed for the inflammation in the tissues around the calculus to subside. Brisk bleeding from inflamed tissues can make the removal of salivary calculi unnecessarily difficult. Once the inflammation has resolved, it is usually possible to palpate a calculus in the anterior part of the duct, especially if the fingers of the other hand elevate the floor of the mouth by pressure applied to the submental region. Quite small calculi may be detected in this manner, even though they do not produce a palpable, hard lump but merely cause a thickening of the duct or give the papilla an unusual firmness. The larger calculi will be seen as yellowish masseselevating the floor of the mouth. A minute calculus which lies in the papilla or just behind it may also be seen, but only as a yellowish discoloration shining through the thin overlying tissues, Because the opening of the submandibular duct is small, it is uncommon
Fig. 7. A calculus ulcerating through the right submandibular the papilla. This is frequently mistaken for a calculus presenting
duct about 3 mm. behind at the papillary opening.
Volume 25 Number 3
Anatomic
surgery
for salivary
calculi
289
for even tiny calculi to peep through the orifice; sometimes, however, the mucosa ulcerates over the stone, and then one end will extend into the mouth (Fig. 7). A central true occlusal radiograph is used to demonstrate anterior calculi, as most of them are radiopaque. However, care should be taken not to overexpose the film, and it is recommended that one use about three fourths the exposure that is usually employed when the same view is used to demonstrate the mandible. In order to see small calculi, the illumination of the viewing screen must be particularly bright, but it should be well masked to avoid glare. Whenever an anterior calculus is discovered, it is a wise precaution to take a posterior oblique occlusal radiograph in order to study the posterior part of the duct and the gland, as it is not unusual to find one or more smaller calculi farther back. OPERATIVE PROCEDURE Patients rarely retch or resist the pressure of retractors during operative manipulations in the anterior part of the floor of the mouth. Indeed, the patient can consciously help by positioning the lips and tongue in a way that improves access to the surgical field. Hence, a local anesthetic is preferred. It is advisable to follow a set routine, for in this way complications are either avoided or surmounted without difficulty. The anesthetization of the tissues is started by a lingual block injection in the retromolar region. It is better to start in this manner because, if the floor of the mouth is infiltrated at the beginning, the injection might dislodge a small calculus which would then roll down into the intraglandular part of the duct. Since the duct may be dilated behind the calculus, even calculi which are larger than the diameter of a normal duct can be dislodged in this way. When anesthesia has been achieved, a suture is passed into the floor of t,he mouth and around the duct posterior to the stone. Once this has been done, there is no longer danger of the stone rolling backward. The duct inclines down to the gland at a moderate angle, so the suture must include a sizable amount of tissue if it is to embrace the duct. The easiest way to achieve this is to insert one suture into the floor of the mouth to a reasonable depth, and then to tent the tissues up with it while a second suture is inserted to pass below the duct (Fig. 8). An error that is frequently made is to place the suture too far laterally, so that it embraces the sublingual gland rather than the submandibular duct. Another error is to insert the needle too far medially, so that the sublingual veins are punctured. This may produce a hematoma which will make the subsequent dissection more difficult. The duct is found bisecting the angle formed by the sublingual plica and the line of attachment of the tongue. It is not necessary to tie the stitch tightly in order to trap the calculus; indeed, if it is tied tightly, the soft tissues of the floor of the mouth can be damage,d. It is sufficient to tighten a single knot until it rests on the floor of the mouth. Then the threads can be passed over the t,eeth and a pair of artery forceps clamped on the end so that their weight will pull the tissues up, kinking the duct. At this stage the floor of the mouth should be infiltrated with a local anesthetic and Adrenalin solution, and once more the sublingual veins must be avoided. Suf-
290 Seward
023, O.M. & O.P. March, 1968
Fig. 8
Fig. 9
Pig. 8. A suture has been passed around the submandibular duct posteriorly by the method illustrated in the inset photograph. An additional suture has been passed beneath the papilla. The floor of the mouth has been infiltrated with a vasoconstrictor, and an incision has been made over the duct. Fig. 9. The duct has been isolated and College tweezers have been passed under it to draw a thread through beneath the duct. The edges of the incision are retracted by sutures, and the sublingual veins appears as a lobulated swelling on the lingual side of the duct.
ficient solution should be injected around the duct to reduce bleeding. A further infiltration is made into the floor of the mouth on the other side, close to the lingual frenum, and a second suture is placed between the submandibular duct papilla and the frenum (Fig. 8). Gentle traction on the two sutures will steady the operation area and will make the mucosa sufficiently taut so that it can be readily cut with the scalpel. An incision is made along the line of the duct and over the stone (Fig. 8). If the calculus is neither visible nor palpable as a guide to the position of the duct, the incision is made along a line which bisects the angle between the root of the tongue and the sublingual plica. Although the knife should not be plunged deeply into the tissues, it should divide the mucous membrane and enter a little way into the underlying connective tissue.
Volume 25 Number 3
Anatomic surgery for salivary
calculi
291
Fig . 10
Fig
Fig. IO. Whi le the duet is steadied by the stay suture an incision is made over the (:alc.UlUS. Fig. 21. The calculus can be picked out of the wound with College tweezers.
ZGg. 1.9. Two sutures are sticient
to close the wound in the floor of the mouth.
0.X., O.M. & O.P. March, 1968
292 Seward
.
Pig. 13. A, The duct has been steadied by a stay suture and a longitudinal incision made over a sizable calculus. The calculus is adherent, however, and a stay suture has been passed through one edge of the incision in the duct so that the calculus can be freed from the duct wall. B, The calculus has been separated from the duct wall and is ready to be lifted out.
By a combination of blunt and sharp dissection with fine, sharp-pointed scissors, the wound is deepened toward the submandibular duct through the loose connective tissue, keeping lateral to the sublingual veins (Fig. 9). Once again, it is preferable to avoid puncturing the veins; should one be cut, however, the bleeding point is ligated with 5-O catgut. The submandibular duct may be identified by its pale, grayish color and by the network of fine capillaries which course over its surface. The duct is gently mobilized, and a stay suture is passed under it with a pair of College tweezers. The fine, curved, pointed tips of the tweezers can be pushed through below the duct, which is raised out of the wound across their blades (Fig. 9). A length of suture material is grasped in the tweezers and pulled through under the duct. If a pair of artery forceps is hung on the end of the stay suture, the operator will have control over the duct during the remaining manipulations. Frequently at this stage the calculus will be seen through the duct wall, and a longitudinal incision will release it (Figs. 10 and 11). If the calculus is a large one it may be adherent to the inside of the duct and, although the incision will expose it, some effort may be needed to free it from the duct wall. Yet another stay suture is inserted into one lip of the incision in the duct so that the operator can separate the calculus by blunt dissection without its bobbing about in a disconcerting fashion (Fig. 13). If the location of the calculus is not indicated by either a swelling of the duct wall or a yellowish discoloration, then the duct should be incised in what is judged from the radiographs to be its position. Should it be necessary, the incision may be extended a little way along the duct with a pair of fine scissors.
Volume 25 Number 3
Anatomic surgery for salivary calculi
293
If the calculus has not been located after this maneuvre, the duct should be milked to squeezeit toward the opening. Once the calculus has been taken out, the ligature that occludes the duct posterior to the surgical area is cut and removed. Milky white, mutinous saliva which has collected behind the stone will flood through the opening in the duct wall. The gland should be gently squeezed between one finger applied to the floor of the mouth over the upper pole and the fingers of the opposite hand npplied to the lower pole. Additional saliva will be discharged, and with it may appear minute calculi not seen in the radiographs. Finally, a pair of mosquito forceps is introduced into the duct to explore the posterior part for unsuspected calculi. To close the wound, all remaining stay sutures are removed and a few interrupted stitches are inserted to approximate the mucous membrane (Fig. 12). The incision in the duct itself is not sutured lest a stricture be created. Provided the duct is patent distal to the incision, no fistula will form.