Combined Manometric-pH Recording Catheter for Esophageal Function Tests

Transcription

1 HOW TO DO T Combined Manometric-pH Recording Catheter for Esophageal Function Tests Mark B. Orringer, M.D., Robert Lee, M.S., and Herbert Sloan, M.D. ABSTRACT A combined manometric-ph recording catheter for performance of esophageal function tests is described. This combined unit has been used successfully in more than 300 patients. t has the advantages of (1) eliminating the need for introduction of two separate recording catheters into the esophagus and (2) permitting simultaneous dynamic recordings of intraesophageal pressures and ph in assessing competence of the distal esophageal high-pressure zone. Esophageal function tests, including manometry and direct measurement of intraesophageal ph, facilitate the diagnosis of functional disorders of the esophagus and provide objective data with which to evaluate the efficacy of antireflux operations [l-51. Our technique for performing esophageal function tests has been described elsewhere [31. Generally, these studies require either nasal or oral introduction of both a triple-lumen pressurerecording catheter and a ph gastric electrode into the esophagus, and may therefore be quite uncomfortable for the patient and technically difficult for the physician performing the procedure. This paper describes our method of constructing a combined, single-unit triplelumen manometric catheter and ph electrode. The combined unit, inserted as a nasogastric tube, is more readily tolerated by the patient and has the added advantage of allowing simultaneous dynamic measurements of intraesophageal pressures and ph in assessing competence of the lower esophageal sphincter mechanism. From the Section of Thoracic Surgery, Department of Surgery, The University of Michigan Medical Center, Ann Arbor, M. Accepted for publication Jan 13, Address reprint requests to Dr. Orringer, Section of Thoracic Surgery, C-7076 Outpatient Building, AM Arbor, M Method Construction of the combined catheter unit requires approximately three to four hours and the following supplies: Beckman stomach ph electrode No Three 150 cm lengths of polyvinyl tubing with an inner diameter of 1.1 mm and an outer diameter of 1.65 mm (e.g., Becton- Dickinson tubing No. 6179) Tetrahydrofuran solvent Several 3-ml syringes with 18- and 25-gauge needles Punch for producing Tygon tubing plugs with the same inner diameter as the polyvinyl tubing Tygon tubing scraps, 2.4 or 3.2 mm thick Mercury, 5 cc Several 5 to 8 cm lengths of stiff polyethylene tubing (approximate inner diameter, 4 mm) slit on one side 9. Nontoxic black marking pen (e.g., Sanford s Sharpie) 10. Nontoxic white marking paint (e.g., Pearly White acrylic paint, Palmer Paint Products, nc., Troy, M 48084) 11. Three 18-gauge needles, blunted The three 150 cm lengths of polyvinyl tubing are straightened by momentary immersion in boiling water to soften them and then hanging vertically for several hours to harden. One tip of each tube is beveled. With tetrahydrofuran carefully applied with a 25-gauge needle and a 3-ml syringe, 1 to 2 cm of the beveled ends of the tubing are sequentially glued to each other and to the ph electrode 1 cm from its tip (Fig 1A). Tetrahydrofuran dries within ten seconds. t is important to keep the protective rubber cap over the ph electrode whenever possible to avoid contact with the tetrahydrofuran. f the solvent dries on the tip, the result is decreased sensitivity of the probe by Mark B. Orringer

2 582 The Annals of Thoracic Surgery Vol 26 No 6 Uecember 1918 C DSTAL OPENNG nat lo scolel MEDAL PROXMAL OPENNG OPENNG Fig 1. Construction of the combined manometric-ph recording catheter. (A) With tetrahydrofuran, the beveled ends of polyvinyl tubing are glued to each other and to the ph probe 2 cm from its tip. (B) A slit cuff of polyethylene tubing approximates the polyvinyl tubing against the ph probe, allowing for sequential gluing. (C) A punch is used to create a side hole in the proximal and medial pressure-recording catheters. The distal catheter records pressures through an end opening. (D) Small plugs of Tygon tubing are made. (E) They are inserted into the polyvinyl tubing to within 1 to 2 mm of the side holes. (F) After the distal ends of the proximal and medial pressure-recording catheters have been filled with mercury, these tubes are sealed with additional Tygon plugs. The ph probe and partially attached polyvinyl tubing are inserted into the slit cuff of polyethylene tubing, which approximates the polyvinyl tubing against the probe and allows for subseauent gluing (Fig 1B). A polvethvlene rather than polyvinyl cuff of tubing must be used because it is not affected by the tetrahydrofuran in gluing the ends of polyvinyl tubing together. Two to 4 cm of the tubing are sequentially pulled through one end of the polyethylene cuff and glued in place using tetrahydrofuran, which is again applied with a needle and syringe and allowed approximately ten seconds to dry before the next application. The polyvinyl tubes are glued to the ph probe for a length of 80 cm. At this point, the slit polyethylene cuff is removed and the polyvinyl tubes are glued together, but not to the ph probe, for an additional 30 cm. A small punch is used to make a side opening in one of the polyvinyl tubes 5 cm from the end opening of an adjacent tube. This adjacent tube arbitrarilv becomes the "distal" pressure-

3 583 How to Do t: Orringer, Lee, and Sloan: Manometric-pH Recording Catheter ph PROBE DS~AL OPENNG MEDAL OPENNG PRO~MAL OPENNG Fig 2. Completed combined manometric-ph recording catheter. The ph probe and attached polyvinyl tubing have been marked of] in Centimeters from the side hole of the proximal recording catheter. The ph probe is connected to a ph meter and the three pressurerecording catheters, to strain xauges. recording catheter, while the punched tube becomes the medial pressure-recording catheter (Fig 1C). To create the proximal pressurerecording catheter, a side opening is made in the last of the three tubes 5 cm proximal to the level of the side opening in the medial recording catheter. Then, using the scraps of thickwalled Tygon tubing and a punch, small plugs with the same internal diameter as the polyvinyl tubing are made (Fig 1D). These plugs are pushed from the end openings of the medial and proximal catheters to within 1 to 2 mm of the side holes and are sealed in place with a small amount of tetrahydrofuran delivered through the side openings (Fig 1E). The ends of the medial and proximal recording catheters distal to the Tygon plugs are filled with mercury, inserted with a needle and syringe, and are sealed with two to three additional Tygon plugs, secured with tetrahydrofuran. Mercury in the recording catheter allows fluoroscopic positioning of the tube, should this be necessary. Using the black marking pen on the polyvinyl tubing and the white marking paint on the ph electrode, the combined unit is marked off in centimeters from the side hole of the proximal recording catheter. ntraesophageal pressures are thus measured in centimeters from the nostril to the side hole of the proximal recording catheter. The medial catheter records pressures 5 cm distal to the proximal side hole and the distal catheter, 10 cm from that side hole. The ph electrode is 11 cm distal to the proximal recording catheter side hole. Blunted 18-gauge needles are inserted into the open ends of the three polyvinyl tubes so that they can be connected with the strain gauges for pressure recordings. The completed combined manometric-ph recording catheter has a smaller diameter than a standard 16F nasogastric tube (Fig 2). The patient s nasopharynx is sprayed with 2% Xylocaine (lidocaine). Using Xylocaine jelly as a lubricant, the combined manometric-ph recording catheter is inserted as a nasogastric tube and advanced into the stomach for standard esophageal function tests as described

4 584 The Annals of Thoracic Surgery Vol 26 No 6 December 1978 RESP. cm - Prox. to Nostril " " " " " " " " 1 " - 5- Ly_ HPZ DSTAL - A H6Z HPZ - - SUPNE RGHT SDE LEFT SDE 20" HEAD DOWN DBDB V V C C DBDB V V CC DBDBV V CC DBDBVV C C l l PH 4 0 L B 4Kt Fig 3. (A) Simultaneous manometry and ph recording using the combined catheter in a patient who had undergone a combined Collis gastroplasty-nissen fundoplication six months earlier. Before the operation, the patient had no distal esophageal high-pressure zone (HPZ) and massive gastroesophageal reflux. Following instillation of 300 ml of 0.1 N hydrochloric acid into the stomach, pull-back pressure tracings from the stomach into the esophagus show a distal esophageal HPZ with approximate mean and peak pressures of 8 and 20 mm Hg, respectively, extending from 43 to 39 cm from the nostrils. Note the sharp rise in intraesophageal ph that occurs when the tip of the ph probe is within the HPZ. The combined catheter is withdrawn until the ph probe is 5 cm proximal to the HPZ and is then taped to the patient's nose for the acid reflux test. (B) Acid reflux test in the same patient. Note that intraesophageal ph neuer falls below 4 during the standard postural maneuvers. The proximal opening of the combined catheter is at 23 cm, and the ph probe is 34 cm from the nostril, which is 5 cm proximal to the upper extent of the HPZ (39 cm). (DB = deep breathing; V = Valsalva maneuver; C = coughing.) previously [3]. A Beckman ph reference potassium chloride electrode is positioned in the corner of the patient's mouth since intraesophageal ph is continuously monitored by the ph probe connected to a ph meter. Pressures and ph are recorded with a Grass sixchannel polygraph. The pressure-recording catheters are constantly perfused with normal saline at a rate of 1.7 ml per minute, and respirations are monitored with a pneumograph placed around the patient's chest. To perform the acid reflux test, after 300 ml of 0.1 N hydrochloric acid has been instilled into the stomach, the combined recording catheter is withdrawn into the esophagus at 1 cm intervals until the tip of the ph probe is 5 cm above the high-pressure zone as determined by prior manometry (Fig 3A). The combined unit is taped to the patient's nose, and intraesophageal

5 585 How to Do t: Orringer, Lee, and Sloan: Manometric-pH Recording Catheter ph is then recorded using standard postural maneuvers to elicit reflux (Fig 3B). The unit is left in place while the acid clearance and acid perfusion tests are done. Comment The combined manometric-ph recording catheter has been used for esophageal function tests in more than 300 patients. No technical difficulties have been encountered. n performing the acid reflux test, simultaneous recordings of distal, medial, and proximal intraesophageal pressures and ph have provided an additional factor by which competence of the distal esophageal sphincter mechanism can be assessed. ntraesophageal ph generally rises sharply when the ph probe is within the distal esophageal high-pressure zone, indicating the presence of a barrier against reflux of gastric contents (see Fig 3). Persistent elevation of the ph above 4 during the postural maneuvers of the acid reflux test documents further the competence of the high-pressure zone. Occasionally, as the combined unit is withdrawn from the stomach into the esophagus, despite the demonstration of "normal" highpressure zone pressures, intraesophageal ph remains below 4. This may be the result of adherence of acid gastric mucus to the tip of the ph probe and can generally be detected by flushing the end opening of the distal catheter with several milliliters of saline. This results in a prompt rise of the ph above 4. The pull-back pressure tracing should then be repeated. The combined manometric-ph recording unit is more readily tolerated by the patient than the two separate standard catheters. The combined unit is more efficient and thus facilitates the evaluation of patients with functional disorders of swallowing. References 1. Benz LJ, Hootkin LA, Margulies S, et al: A comparison of clinical measurements of gastroesophageal reflux. Gastroenterology 62: 1, Orringer MB: Esophageal function tests in the modem age of esophageal surgery (editorial). Ann Thorac Surg 22:204, Orringer MB, Dabich L, Zarafonetis C, et al: Gastroesophageal reflux in esophageal scleroderma: diagnosis and implications. Ann Thorac Surg 22:120, Orringer MB, Sloan H: Collis-Belsey reconstruction of the esophagogastric junction. ndications, physiology, and technical considerations. J Thorac Cardiovasc Surg 71:295, Skinner DB, Booth DJ: Assessment of distal esophageal function in patients with hiatal hernia and/or gastroesophageal reflux. Ann Surg 172:627, 1970