Method for retrieving pancreatic juice utilizing and endoscopically wire-guided catheter

A method for accurately and quickly positioning a double lumen gastroduodenal tube into predetermined locations utilizing an endoscopically placed guide wire to retrieve duodenal fluid uncontaminated by gastric fluid, with little or no discomfort to the patient, and minimal radiation exposure. Specifically, an endoscope is passed through a patent's esophagus and stomach into the duodenum such that its distal end is located at a predetermined location, such as the fourth portion of the duodenum. While the endoscope is held in place, a guide-wire is passed through its center instrument channel to position a distal end of the guide-wire adjacent to the distal end of the endoscope. The endoscope is then withdrawn from the patient, leaving the guide-wire. A double lumen gastroduodenal tube is then threaded over the guide-wire such that gastric ports are aligned with the stomach and duodenal ports are aligned with the fourth portion of the duodenum so that upon aspiration of the gastric ports, the gastric fluid is prevented from entering the duodenum and contaminating the duodenal fluid.

FIELD OF THE INVENTION 
The present invention relates generally to a method for using a catheter to 
diagnose chronic pancreatitis and, more specifically, to a method for 
positioning a double lumen gastroduodenal robe using an 
endoscopically-placed guide-wire. 
BACKGROUND OF THE INVENTION 
Chronic pancreatitis is usually characterized by a progressive loss of 
pancreatic parenchymal tissue. In many individuals, chronic pancreatitis 
is clinically silent. Further, many patients with unexplained abdominal 
pain may actually have chronic pancreatitis that eludes diagnosis. Chronic 
pancreatitis is associated with a mortality rate that approaches 50 
percent within 20 to 25 years. Approximately 15 to 20 percent of patients 
die of complications associated with attacks of pancreatitis. It has 
recently been reported that pancreatic cancer develops in approximately 4 
percent of patients within 20 years of a diagnosis of chronic 
pancreatitis. 
With the rapid evolution of pancreatic imaging over the last two decades, 
computerized tomography and endoscopic retrograde pancreatography (ERP) 
have become invaluable tools in the evaluation and management of 
pancreatic disorders. Nevertheless, chronic pancreatitis has been reported 
in up to 24% of patients having a negative diagnosis with these 
non-invasive techniques. 
Direct invasive pancreatic function testing plays an important role in the 
diagnosis of abdominal pain of unclear etiology, especially when 
pancreatic disease is suspected in spite of negative imaging tests. 
Conventional invasive techniques for pancreatic juice collection used to 
supplement or replace the above imaging techniques include the 
secretin-pancreozymin test as well as the intraductal sampling technique. 
The secretin-pancreozymin test involves the collection of duodenal fluid 
and the measurement of various characteristics after the inducement of 
pancreatic functions. Although the secretin-pancreozymin test has been 
shown to have a sensitivity and specificity in the 90% range, its use in 
the United States has been limited to few specialized centers. This is due 
to its complexity and cumbersome nature, resulting in the inability to 
successfully pass a Dreiling.TM. catheter into the duodenum of 
approximately 20-50% of the patients. This degree of difficulty increases 
the cost of the procedure by requiring the administration by trained 
technicians. Furthermore, the time involved to pass the catheter into the 
duodenum on the remaining 50-80% of the patients takes from 0.5 to 2 
hours. In addition, the discomfort experienced by the patient narrows the 
applicable use of the technique to only those extreme conditions where its 
use is essential. This is particularly true in patients having motility 
disorders of the gastrointestinal (GI) tract, which is seen in up to 20% 
of those referred for testing. 
In the intraductal sampling technique, pure pancreatic juice is collected 
using a 1.5 mm catheter placed into the pancreatic duct by 
gastroenterologic procedures (ERP). Although this technique has been shown 
to yield similar results to the secretin-pancreozymin test, it requires a 
highly skilled endoscopist because it requires the selective localization 
of the main pancreatic duct, followed by deep cannulation and placement of 
a collection catheter deep within the pancreatic duct. Furthermore, this 
process has the risks inherent to an ERP. 
Thus, it has been determined that chronic pancreatitis can be difficult to 
diagnose, especially in the initial three to five years of disease. As a 
result, most patients undergo repeated testing which usually includes 
multiple imaging and invasive evaluations. 
What is needed, therefore, is a method for obtaining pancreatic juice that 
does not require an experienced technician to administer, and which can be 
successfully administered quickly and cost effectively, regardless of GI 
motility. Furthermore, the method must not cause significant patient 
discomfort to reduce patient resistance to the technique. 
SUMMARY OF THE INVENTION 
The present invention is an improved method for accurately and quickly 
positioning a double lumen gastroduodenal tube into predetermined 
locations utilizing an endoscopically placed guide wire to retrieve 
duodenal fluid uncontaminated by gastric fluid, with little or no 
discomfort to the patient. 
Specifically, the endoscopic guide-wire placement method of the present 
invention includes a series of steps, the first of which is the feeding of 
an endoscope through the patient's esophagus and stomach into the 
duodenum. The endoscope is positioned such that its distal end is located 
at a predetermined location in the duodenum. The endoscope is then held in 
place while a guide-wire is passed through a center instrument channel of 
the endoscope to position a distal end of the guide-wire adjacent to the 
distal end of the endoscope. Once it is verified that the guide-wire is 
properly placed, the endoscope is withdrawn from the patient, leaving the 
guide-wire. The position of the guide-wire is then verified by 
fluoroscopy. 
A double lumen gastroduodenal tube is then threaded over the guide-wire. 
The tube includes a duodenal lumen disposed adjacent to a separate gastric 
lumen for removing duodenal and gastric fluids, respectively. In an 
alternative embodiment, the duodenal lumen is concentrically disposed 
within the separate gastric lumen. The gastric lumen has gastric ports at 
its distal end for receiving gastric fluid. Similarly, duodenal ports are 
placed at a distal end of the duodenal lumen, which extends beyond the 
gastric lumen, for receiving duodenal fluid. 
Proper placement of the tube is achieved when the gastric ports are aligned 
with the stomach and the duodenal ports are aligned with a predetermined 
portion of the duodenum. This placement may be verified by fluoroscopy. 
Once the proper location of the ports is verified, the guide-wire is 
withdrawn from the patient. 
To retrieve uncontaminated duodenal fluids, the gastric fluids are 
continuously aspirated through the gastric ports to prevent the gastric 
fluids from entering the duodenum. Simultaneously, the duodenal fluid is 
aspirated through the duodenum ports for subsequent analysis of the 
duodenal fluid. 
Alternatively, other methods are contemplated for preventing gastric fluid 
contamination of the duodenal fluid prior to aspiration. For example, a 
balloon may be incorporated into the procedure in place of the gastric 
tureen. Specifically, an endoscopic wire-guided method similar to that 
described above is implemented to place a duodenal tube in a desired 
location of the duodenum. Then, a tube having a balloon at its distal end 
may be placed over the a duodenal tube to position the balloon at a 
location between the stomach and an entry point at which the pancreatic 
juice enter said duodenum. The balloon is then inflated to prevent gastric 
fluids from entering the duodenum. While the balloon is inflated the 
duodenal fluid is aspirated as above. 
Advantageously, the present invention enables the accurate placement of the 
double lumen gastroduodenal tube within minutes, thereby reducing 
discomfort and adverse reactions by the patient. In addition, the present 
invention can be successfully completed on all patients. Furthermore, 
implementation of this process may be performed by technicians in an GI 
endoscopy unit without the need for specialized trained personnel. 
Moreover, the use of an endoscopically placed guide wire eliminates the 
need to gravity feed the catheter by following an unobstructed path. 
Significantly, the present invention enables rapid tube placement 
regardless of gastrointestinal motility. Furthermore, the rapid tube 
placement reduces the time in which fluoroscopy is utilized. As a result 
of the decreased fluoroscopy, the patient and technicians are exposed to 
significantly decreased radiation level. In some instances, for example, a 
reduction in radiation exposure of up to 75% has been achieved. 
Further features and advantages of the present invention as well as the 
structure and operation of various embodiments of the present invention 
are described in detail below with reference to the accompanying drawings. 
The principles and features of this invention may be employed in various 
and numerous embodiments without departing from the scope of the 
invention. In the drawings, like reference numbers indicate identical or 
functionally similar elements. Additionally, the left-most digit of a 
reference number identifies the drawing in which the reference number 
first appears.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention is an improved method for accurately and quickly 
positioning a double lumen gastroduodenal robe into predetermined 
locations utilizing an endoscopically placed guide wire to retrieve 
duodenal fluid uncontaminated by gastric fluid, with little or no 
discomfort to the patient. 
FIGS. 1-5 illustrate the location of the endoscope, guide-wire, and double 
lumen catheter after each of the steps of the preferred embodiment of the 
present invention. Referring to FIG. 1, the endoscopic guide-wire 
placement method of the present invention includes a first step which is 
the feeding of an endoscope 112 through the patent's esophagus 102 and 
stomach 104 into the duodenum 108. 
Endoscope 112 has a proximate end 118 that does not enter the patient's 
body and a distal end 116 having a camera 114. Specifically, the endoscope 
112 is positioned such that its distal end 116 is located at a 
predetermined location in duodenum 108 wherein at a later step duodenal 
fluid is aspirated. (discussed below). Generally, the duodenal fluid is 
aspirated distal to the ampulla of vater. The ampulla of vater is the 
structure in which the pancreatic duct 110, which extends from the 
pancreas 106, enters the duodenum 108. In the preferred embodiment the 
predetermined location is the fourth portion 120 of duodenum 108. This 
step is completed once endoscope 112 is properly positioned in the 
duodenum 108. This may be verified, for example, by fluoroscopy. 
In the preferred embodiment of the present invention, the endoscope is a 
commonly available standard 9 mm videoendoscope. However, other types 
endoscopes may be used that are appropriate for a given application. 
FIG. 2 is an illustration of the next step of the present invention wherein 
a guide-wire 202 (shown by dashed lines) is passed through a center 
instrument channel 204 of endoscope 112. The diameter of the center 
instrument channel of endoscope 112 is dimensioned, with respect to the 
guide-wire, to provide sufficient wire clearance to allow the guide-wire 
to be moved easily through the endoscope in an axial direction, during 
placement of the guide-wire 202. 
Under fluoroscopic guidance, all loops (not shown) of endoscope 112 are 
reduced and guide wire 202 (shown by dashed lines) is advanced through the 
endoscope center instrument channel 204 until a distal end 206 of the 
guide wire 202 is positioned at the predetermined location; that is, 
adjacent to the distal end 116 of endoscope 112 at the Ligament of Treitz 
120. 
In the preferred embodiment of the present invention, the guide wire is a 
conventional 210 cm spring tip type guide wire, available from Bard 
Interventional Products, Tewksbury, Mass., USA. However, as one skilled in 
the art would find apparent, other guide-wire types and sizes may be used 
that are compatible with the chosen double lumen catheter and endoscope, 
as well as the selected external body access site and resulting path by 
which the predetermined location is reached. 
Once it is verified that guide-wire 202 is properly placed, endoscope 112 
is withdrawn from the patient, leaving the guide-wire, as shown in FIG. 3. 
The verification of the position of the guide wire may be performed, for 
example, by fluoroscopy, although other methods may be used. The use of an 
endoscopically placed guide wire eliminates the need to gravity feed the 
catheter by following an unobstructed path. Significantly, this aspect of 
the present invention enables rapid tube placement regardless of 
gastrointestinal motility (discussed below). 
Referring to FIG. 4, a double lumen gastroduodenal tube 402 is then passed 
over guide-wire 202 (shown by dashed lines). The guide-wire 202 is 
sufficiently rigid to enable the tube 402 to easily track the wire down to 
the predetermined location. Tube 402 includes a duodenal lumen disposed 
adjacent to a separate gastric lumen for removing duodenal and gastric 
fluids, respectively. In an alternative embodiment, the duodenal lumen is 
concentrically disposed within the separate gastric lumen. As shown in 
FIG. 4, the duodenal lumen 406 extends past the distal end 410 of the 
gastric lumen 404, which terminates at the location of the stomach 104. 
Gastric lumen 404 has gastric aspiration ports 412 at its distal end 410 
for receiving gastric fluid. Similarly, duodenal lumen 406 has duodenal 
aspiration ports 414 at its distal end 408 for receiving duodenal fluid. 
The separate lumens 404, 406 prevent contamination of the duodenal fluid 
by the gastric fluid. 
Since the guide wire 202 is positioned at the desired location of the 
duodenum, the duodenal lumen 406 is threaded over guide-wire 202, as shown 
in FIG. 4. While the duodenal lumen 406 is threaded over guide wire 202, 
tension is kept on the wire 202 to avoid looping of the tube in the 
stomach. (not shown) Preferably, the portion of the guide wire 202 
disposed outside of the patient's body is lubricated to facilitate the 
threading of the tube. The inner diameter of the duodenal lumen 406 is 
dimensioned, with respect to the guide-wire, to provide sufficient wire 
clearance to allow the catheter to be moved easily over the wire in the 
axial direction during catheter placement and, as discussed below, 
guide-wire removal. 
As shown in FIG. 4, the tube is advanced into the fourth portion of the 
duodenum 120 and its position is confirmed, preferably under fluoroscopy. 
At this position, gastric aspiration ports 412 are directly aligned with 
the stomach 104 and the duodenal aspiration ports 414 are directly aligned 
with duodenum 108. 
In the preferred embodiment of the present invention, the double lumen 
gastroduodenal tube is a Dreiling.TM. tube, available from Davol, Inc., 
Cranston, R.I., USA. However, as one skilled in the art would find 
apparent, other types of double lumen tubes that separately aspirate 
gastric and duodenal fluids may be used. 
Once the proper locations of the ports 412, 414 are verified, the 
guide-wire 202 is withdrawn from the patient and the tube 402 is secured 
in its desired location as shown in FIG. 5. Advantageously, the present 
invention enables the accurate placement of the double tureen 
gastroduodenal tube 402 within minutes, thereby reducing discomfort and 
adverse reactions by the patient. Furthermore, implementation of this 
process may be performed by technicians in an GI endoscopy unit without 
the need for specialized trained personnel. 
Significantly, the above procedures of the present invention are performed 
on the patient while the patient is asleep. Preferably, the patient 
receives topical cetacaine and is premedicated with midazolam. An 
intravenous line is placed in the patient and the patient is sedated with 
I.V. Versed in conjunction with oropharyngeal anesthesia using 10% 
Lidocaine spray. Subsequent to the above procures, the patient is then 
brought to the recovery room, and with the patient in a reclining chair 
the remaining procedures are performed. Since the remaining procedures are 
passive in nature, the patient need not remain asleep during their 
completion. 
Referring to FIG. 6, the proximate end 614 of the duodenal lumen 406 is 
connected to a tube 608 which is connected to a flask 610. A first end 616 
of an additional tube 606 is placed in the flask 610 with the proximate 
end 614 of the duodenal lumen 406. The other end 618 of the tube 606 is 
connected to a suction device 602. In addition, the proximate end 612 of 
the gastric lumen 404 is connected directly to a second suction device 
604. 
The suction devices 602, 604 are then activated to aspirate from the 
proximal ends 612, 614 of the gastric and duodenal lumen 404, 406, the 
gastric and duodenal fluids. To retrieve uncontaminated duodenal fluids, 
the gastric fluids are continuously aspirated through the gastric 
aspiration ports 412 from the stomach 104 to prevent the gastric fluids 
from entering the duodenum and mixing with the pancreatic juice entering 
the duodenum 108 through duct 110. 
Simultaneously, the duodenal fluid is aspirated through the duodenum 
aspiration ports 414 from the duodenum 108 for subsequent analysis. 
Preferably, for chronic pancreatitis, the duodenal fluid is periodically 
aspirated for analysis of differential changes in the duodenal fluid. 
In an alternative embodiment, the gastric fluids are prevented from 
contaminating the duodenal fluid prior to aspiration by the use of a 
balloon (not shown). The balloon may be incorporated into the procedure in 
place of the gastric lumen. Specifically, an endoscopic wire-guided method 
similar to that described above is implemented to place a single lumen 
tube in a desired location of the duodenum. A tube having a balloon at its 
distal end then may be placed over the single lumen tube to position the 
balloon at a location between the stomach and an entry point at which the 
pancreatic juice enter the duodenum through duct 110. 
The balloon is then inflated to prevent gastric fluids from entering the 
duodenum. The guide-wire is then removed from the patient. While the 
balloon is inflated the duodenal fluid is periodically aspirated, as 
indicated above. 
In another alternative embodiment, acid production by the stomach may be 
blocked by medication. Duodenal fluid is then periodically aspirated, as 
indicated above. 
With respect to any of the methods identified above, once the 
uncontaminated duodenal fluid has been aspirated from the duodenal ports, 
any desired analysis, now or later developed, may be performed on the 
duodenal fluid to diagnose chronic pancreatitis. Specifically, in the 
preferred embodiment, the pH of both the gastric fluid and duodenal fluid 
content is calculated. The pH of the duodenal fluid is analyzed with pH 
paper and should be approximately 8. Fluid from the gastric port should be 
less than 7. Subsequent to the calculation of the pH of both fluids, the 
periodic aspiration of the duodenal fluid includes collecting and saving 1 
to 5 ml of duodenal fluid for a baseline measurement. A secretin 
stimulation test is performed using the standard protocol. Specifically, 
secretin (1 unit/kg) is given intravenously over 1 minute via a rapid 
running IV line. Duodenal fluid is then collected every 15 minutes for a 
total of one hour. The Dreiling.TM. catheter is then removed. The volume 
of duodenal fluid collected at each 15 minute interval is recorded and an 
analysis is performed for total bicarbonate. Bicarbonate concentration is 
determined by back titration. A bicarbonate concentration of 80-120 
millequivalents/liter (mEq/L) is normal. Bicarbonate concentration less 
than 80 mEq/L is diagnostic of chronic pancreatitis. A normal bicarbonate 
concentration but decreased volume output is consistent with pancreatic 
duct obstruction and should prompt an ERCP. 
Furthermore, the terms and expressions which have been employed are used as 
terms of description and not of limitation, and there is no intention, in 
the use of such terms and expressions, of excluding any equivalents of the 
features shown and described or portions thereof, but it is recognized 
that various modifications are possible within the scope of the invention 
claimed.