Anatomic surgery for salivary calculi

Anatomic Part

V.

surgery for salivary calculi Calculi

Cf. R. Xemrd, THE

P

LONDON

in

the

M.D.&‘., HOSPITAL

extraglandular

part

E’.D.S.R.C’.S., MEDICAT,

X.B.,

of

the

B.S.,

parotid

London,

duct

England

COLLEGE

arotid calculi are much less common than submandibular ones, and this is fortunate, since the anatomic environment of the parotid gland presents more difficult, surgical problems. Nevert,heless, these problems are by no means insoluble. Parotid calculi can bc small, and then they may well appear at the parotid papilla. Here, because of the submucous course of the terminal part of the duct, they are found as yellowish swellings just beneath the mucous membrane. Some can partially protrude from the orifice of the duct. Indeed, because the opening of the parotid duct is larger than that of the submandibular duct and therefore only slightly narrower than the lumen, they are more likely to do this than are submandibular calculi. The larger parotid calculi are usually found external to the buccinator muscle in either the intra- or the extraglandular part of the main duct. Not all parotid calculi are radiopaque. Perhaps it is more accurate to say that whereas some are truly radiolucent, others are, in fact, radiopaque but, by virtue of their position, are difficult to demonstrate by plain radiography. Of those calculi which are truly radiolucent, the majority are small and seedlike and appear to be composed of a horny material. One much larger radiolucent calculus that has been removed was pale blue and translucent in the fresh state, almost like cartilage. Parotid calculi may be found at four sites: (1) impacted at the papilla, (2) in the submucous part of the duct,, (3) in the extraglandular part of the duct external to the buccinator muscle, or (4) in the intragla.ndular part of the duct,. Calculi also have been seen to develop in the periphery of the gland in sialoangicctatic cavities. Here it is possible for a calculus to be dislodged and to pass down to the papilla, there to become impacted. p"l,..l: :,. *,,.> 1: 1 2~1 L.. -....1 I,cLLVLI,L LUI~ IU& ii& presence known in a ma,nner 810

Volume 25 Kumber 6

dnntomic

surgery

for salivary

calculi

81 1

similar to t,he more common submandibular calculi, with either obstructive symptoms or attacks of ascending infection. There is one important difference, however, between the parotid and the submandibular glands. As the parotid gland is more superficial, the position of the calculus can be assessed by observing the extent of the swelling. For example. if the accessory parotid becomes swollen, then the calculus lies dista.1l.v in the duct (Fig. 27, B j. If t.he swelling is confined to the lower pole of the gland (Fig. 40, _1), however, then the calculus is in t.he int.raglandular part of t,he duct, often near the point at, which it, crosses the posterior border of the ramus of the mandible. CALCULI IMPACTED AT THE PAPILLA SUBMUCOUS PART OF THE DUCT Preoperative assessment

OR IN THE

Preoperative assessment is usually quite easy, as the calculus may be seen tither partially protruding from the papilla or shining yellow through the mucous membrane which covers the subepithelial segment of the duct. On other occasions the presence of a calculus may be suspected because the submucous part of the duct is distended with saliva, producing a bluish swelling. If, in such a case, a fine probe is introduced into the duct’s entrance, saliva will gush out, but the flow will be cut off as soon as it is withdrawn and the calculus blocks the opening once more. Distension of the submucous part of the duct because of impaction of a caIculus in the pa.pilla must be differentiated from distension due to papillary stenosis. Where a calculus is suspected but not seen, a pcriapical s-ray film packet ran be applied against the inner aspect of the cheek so as to cover the papilla.. Provided that only a small exposure is given, even a poorly calcified calculus will be demonstrated by this technique. Operative

procedure

Calculi in this situation can be rclt~asetl by slitting the papilla. One blade 01 a pair of fine, sharp-pointed scissors is inserted a little way into the duct, and a short cut is made backward from the opening. If the calculus does not, pop out as soon as the scissors a.rc removetl , gentle pressure. on the gland will squeeze a litt,le bit of saliva along the duct, washing out the calculus. The short slit heals rapidly and without permanent enlargement of the orifire. CALCULI IN THE EXTRAGLANDULAR TO THE BUCCINATOR MUSCLE Preoperative assessment

DUCT,

EXTERNAL

A calculus that is just proximal to t 11~ bllc*cinator mnsclc can bc ctemonstratrtl by a periapical film applit~cl flat against the inside of the cheek, but calculi in the segment lvhich curves around the anterior border of the massetel ~nuscle cannot be demonstratrtl by this method. For calcali in this region: a posterior oblique occlnsal radiograph is required (Fig. 27, ;I). For this technique, a film packet jocclusal size) is passed into the mouth with its long axis 1Sing anteroposteriorly. With the mouth partially closed, the film is drawn lateraNy into the cheek, and the patient is told to bite gently

OS., O.M. & O.P. June, 1968

Fig. 27. A, Part of a posterior oblique occlusal radiograph showing a calculus in the left parotid duct. The zygomatie arch forms a prominent shadow passing across the film to the maxilla, and the calculus is seen at the bottom left-hand corner of the film. B, Comparison of the right- and left-hand sides of the face of this patient reveals a swelling below the right aygomatic bone. It is caused by a distended accessory parotid gland. The patient had a calculus in the parotid duct just anterior to the accessory parotid gland.

on the packet to hold it. The anterior part of the parotid duct now lies on top of the film. The tube of a dental x-ray machine is angled downward at 70 degrees and pointed forward and slightly medially, so as to project as much as possible of the duct onto the film. A small exposure is given to avoid overexposing the calculus. It can be difficult to estimate, from plain films, just where a calculus lies in the extraglandular part of the parotid duct, because of the highly curved course of this segment. Therefore, a sialogram can be very helpful, but this procedure should be used only if the calculus is of a reasonable size and unlikely to move backward as the contrast medium is injected. Even with a reasonably large calculus, it is advisable to inject only a small quantity of solution. Provided a calculus has been demonstrated by plain radiography, it is sufficient to fill the duct as far as the front of the calculus in order to establish its position. Fortunately, multiple parotid calculi are uncommon and, since excision of the parotid gland is not a simple matter, the state of the gland has little bearing ,-,,, thn ..L.n:.. I. I’ t,rL i .,LV~l Ed cau wcii be assessed postoperatively. Where only

\rolun~e Number

25 6

Fig.

Fig.

.2X.

5 been pt oe\vhat & at. Big. 29. .t:r surfatt

lose-up photograph of the inside anterior to the parotid papilla AXI by the pull of the silk suture.

28

wl hich of the right cheek, showin g the stitch and the y-shaped incisio In. The y-shap e is The arrow marks the oper ting of the par otid

A F,iew similar to that shown in Fiz. 28. but with the flans ra riscd to expose :e of the buccinator muscle. The triangular flap containing ihr Imrot,id papilla

‘n drawn m r d ially, exposing its undorsurfacr. face of t1ke fls up to enter the buccinator musclr.

The

duct

can be seen passir ig from

the has the un dcr-

the tiist,al part of the duct is to be filled, it is essential to position both patient dte‘r ant1 tube prior to the injection, so that, the exposure can be made shortly the injection has been romplctecl. If this is not done, there is a ~hancc that the wni rnst solution will reAus befow the exposure has been made.

Operative

procedures

Calculi in that part of the extraglandular course of the parotid duct which is superficial to the buccina.tor muscle can be reached via. an incision in the oral aspect of the cheek. Briefly, a Y-shaped incision is made around the parotid

O.R., 0.x June,

Fig.

& 02. 1968

JO

Pig. JO. The edges of the buccinator dehiscrnce have been dram apart, eaposing tile buccal pad of fat, covered at this stage by the delicate buccopharyngeal fascia. 3%~. 31. A silk thread has been passed around the parotid duct, and the part of the duct \vhieh normally lies external to the buccinator has been everted into the mouth. The two instruments are retracting the buccal pad of fat.

papilla, and the duct is identified in the wound and traced into the substance of the cheek. A segment of the duct is mobilized and drawn into the mouth to give the operator access to the calculus. Two transfixing stitches are insert,ed a short distance from the angle of the mouth-one through the upper lip and one through the lower. These are used as retractors to stretch the cheek and draw it out laterally. With a fine hypodermic needle, a solution of Adrenalin 1:80,000 is injected into the submucosa above and below the parotid papilla to reduce bleeding and to lift the mucous membrane off the buccinator muscle. A Y-shaped incision is made, using just sufficient pressure with the scalpel membrane. The t,wo divergent limbs of the Y pass a to penetrate the I~UCO~S little above and a little below the papilla and meet just in front of it,. The upper limb is cut in continuity with the stem, and the stem passes horizontally forward from the papilla. A short lower limb, about 0.4 cm. long, is cut separat,clp. Because of the elasticity of the cheek, 0.75 cm. is a sufficient len&h for thp ,,nncr liml, .>nrJ 1 _,..j.i. f,; ZIG 0kl11 ui Gle Y (l+“ig. 28).

Volume Number

A~zatomic

25 6

surgery

fey salivary

calculi

815

P i,q .

Fig.

33.

A

P ‘in.

3.1, H

Rig. 3’Z. A, An incision has been made in the duct to expose the calculus. One edge of the inc*isiou is grasped by the forceps, and the other is held up by the silk stay suture. 3, The calculus is being lifted out by the forceps. Fig. 9.1. 8, Photograph showing how the opening in the buccinator is closed with a COW linuous vatgut, sutur?. B, closure of the wound in the cheek with interrupted silk sutures.

(Yookse~’ h;ts dcscrihccl a curved, vertical incision made with the concavity fac*ing the papilla, but it ha,s been my experience that vertical incisions in the chrek mucosa heal more slowlp than horizontal ones. A traction snturc is passed through the apex of the triangle of mucosil otlt1inet.t hi- the two limbs of the incision and immcdiatel~ in front of the papilla. ( Pig. 28). It, is now possible to Mist: the tip of the triangle by sharp riisswtion with ;L pair of pointccl scissors. As this is done, the deq surface Of ,+LS ‘1 of the upper and lower flaps l11(~I,uwillatoi- nlliscic is itirrttilit4. The c,‘,r ilrt’ raisctl next, following the surface of the buwinator. Silk stay sutures ales cussed as soon as possible through thew flaps to act as retractors. Thq- will save the mucosa from the damage that can be caused 1~~ grasping it, with ciissecting forceps or by repeatedly engaging skin hooks. Once the upper and lower flaps have been underminetl for the full length of the incisions, the operator returns to the triangular flap ant1 earefull>V continues the dissection to the point at which the parotid duct turns laterall? and pierces the buccinator (Fig. 29).

O.S.,O.M.&O.P. June, 1968 the connc&ve tissue 011 the deep surface of the triangular flap as it is retracted medially. From the deep surface a thick ridge of connective tissue, which also contains the duct, passes lat.erally into the buccinator. Anterior to the point where the duct disappears into the substance of the check, a small part of the buceal pad of fat can be seen covered only by the delicate, cream-colored, buccopharyngeal fascia. The fibers of the buccinator muscle separate to allow passage of the parotid duct but do not come together immediately, and it is in this interval that the buccal pad of fat is seen. The opening is called the buccinator dehiscence. Two more retraction sutures are passed, and their ends are held in artery forceps. One picks up the upper and the other the lower edge of the bnccinator dehiscence. When the sutures are drawn apart, the muscle is split in line with its fibers so as to enlarge the dehiscence (Fig. 30). It is now possible to trace the duct through the buccinator and out into the cheek. The duct is mobilized, and a pair of College tweezers or fine, curved artery forceps is passed around behind the duct, and a length of suture silk is drawn through. With the aid of the silk thread, a loop of duct is drawn medially out from the wound (Fig. 31). A substantial part of the extraglandular segment of duct can be displayed by this maneuver. More of the duct, including the part from which the accessory parotid arises, can be reached if the buccal pad of fat is retracted with Langenbeck’s retractors. Should the duct about the calculus be adherent to the adjacent tissues, the adhesions should bc divided with care, since a branch of the facial nerve which supplies the upper lip usually lies on the outer surface of the duct for part of its course. A short incision is made along the length of the duct so as to open it over and anterior to the calculus (Fig. 32, a). A stitch is passed through one edge of the incision to steady the duct, and the stone is removed (Fig. 32, B). The lumen of the duct is gently irrigated with saline solution and sucked out, but the incision in its wall is not closed. A continous suture of 5-O plain catgut is used to close the buccinator around the duct (Fig. 33, A), and the mucous membrane is sutured with intcrruptcd silk sutures (Fig. 33, B). REFERENCE

1. Cooksey, The C.

D.

E. : In

Kruger,

G. 0. (editor) 543-545.

V. Mosby Company, pp.

: Textbook

af

Oral

Surgery,

St.

Louis,

1959,