US 3459188 A
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g- 5, 1959 M. ROBERTS 3,459,188
PARACENTESIS STYLET CATHETER Filed July 26, 1965 mrvwron Ill/UM 1708!! A TTORIVE Y United States Patent U.S. Cl. 128--347 4 Claims ABSTRACT OF THE DISCLOSURE A catheter-stylet combination for puncturing a patients abdominal wall for peritoneal dialysis. A rigid wire stylet fits within a bore of a laterally flexible plastic catheter and has a point on one end protruding from the catheter and a handle engaged on the opposite end of the catheter. The catheter has a larger internal bore than the stylets diameter and has a series of ports through the catheters wall extending from the one end to form a sieve portion permitting fluid to enter immediately after insertion while filtering out clots. The stylet is substantially centered within this sieve portion by inwardly extending flanges surrounding the ports so that the flexible tube and piercing element combine to form a rigid combination facilitating penetration into a body cavity while affording substantial control as to depth of penetration.
My invention pertains to a medical paracentesis instrument for inserting a fluid conduit through a patients body wall and into a body cavity with a minimum of trauma and bleeding, such as in abdominal or thorax paracentesis procedures.
Unlike tubes and catheters inserted through a natural body passage, such as gastrointestinal, urethral, or rectal, a conduit entering the abdominal or thorax cavity must penetrate a body Wall. This penetration is usually accomplished with a scalpel making a surgical incision, a hollow hypodermic needle, or a metal trocar puncturing a hole.
The surgical incision method requires a general or spinal anesthetic and is performed in an operating room. After the patient is anesthetized, the physician cuts an opening through the patients body wall with a scalpel. He then inserts the catheter through the opening and closes the wound around the catheter with a purse-string suture to prevent bleeding and fluid leakage around the catheter.
The trocar method is preferred over the incision method because it requires only a local anesthetic at the point of puncture. This method involves pushing a sharpened metal sleeve with a pointed obdurator in its bore through the patients body wall. After removal of the obdurator, a catheter is fed through the bore of the metal sleeve holding the wound open. Once the catheter is through the body wall, the metal sleeve is pulled out and the wound sutured shut around the catheter. The trocar method can be used with patients who need frequent dialysis, sometimes as often as every day, but the large hole made by the metal sleeve is traumatic to the patient and takes a long time to heal.
The paracentesis instrument of my invention is functionally and physiologically superior to existing devices,
and provides a simple, safe and economical way of inserting a sieve portion of a thermoplastic catheter through a body wall and into a body cavity. It punctures a hole smaller than the catheter itself and much smaller than the hole made by a metal trocar for inserting a similar size conduit. Such a small hole eliminates the need for pursestring sutures to draw the wound tightly around the catheter.
My invention can perhaps be understood best by reference to the following drawings, in which:
FIGURE 1 is a front elevational view of the medical instrument ready for piercing insertion through a body wall;
FIGURE 2 is a front elevational view of the catheter of the medical instrument extending through a body wall with a sieve portion inside a body cavity;
FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 1; and
FIGURE 4 is a front elevational view of a modification of the medical instrument which is adapted for insertion into a chest cavity.
The paracentesis instrument shown in FIGURES I, 2, and 3 is particularly suited for insertion into an abdominal cavity for peritoneal dialysis. It includes a catheter or conduit element 1 with a wall 8 having an external wall surface 10 and an internal wall surface 9 defining a bore ex tending between the first end 2 and second end 3 of the catheter. An elongated piercing element 12 within the bore of catheter 1 has a pointed end 5 extending from a first end 2 of catheter 1. The external wall surface 10 adjacent the first end 2 tapers radially inwardly toward the pointed end 5 of the elongated piercing element to provide a smooth transition between the catheter 1 and the piercing point 5. Handle 6 extends from the second end 3 of the catheter 1, and abuts this end, limiting the longitudinal movement of the catheter 1 relative to the elongated piercing element 12 upon piercing insertion into a body cavity. The catheter 1, which is generally from 5 inches to 18 inches in length, has sufiicient columnar rigidity to pierce the body wall along with the elongated piercing element 12 when force is applied to handle 6.
Adjacent the first end 2 of the catheter 1 is a sieve portion 13 adapted to go inside a body cavity 17. This sieve portion 13 has a series of ports 4 through wall 8 providing fluid passage into and out of the catheter bore. This sieve portion has small ports 4 with diameters in the range of 0.010 inch to 0.025 inch to filter out any clots or omentum' that may clog fluid passages through the catheter bore.
An additional feature of this invention is a puncture indicator provided by a space 7 as shown in FIGURE 3 between the elongated piercing element 12 and the internal wall surface 9 of catheter 1. Upon piercing a body Wall 16, any fluid within the body cavity will well up in space 7 and be visible outside the body wall through transparent or translucent catheter 1. Such an indicator feature is very useful in peritoneal dialysis for showing when the peritoneum 20 has been pierced and the catheter is in the abdominal cavity. Ports 4 have annular flanges 11 surrounding them and extending inwardly from internal wall surface 9 to spacedly hold elongated piercing element 12 a distance from internal wall surface 9.
FIGURE 2 shows the catheter inserted through the wall 16 of a patient with sieve portion 13 extending into body cavity 17. A portion of the catheter 1 adjacent sieve portion 13 has a preformed curve. This curved portion is straightened when elongated piercing element 12 is within catheter 1, but snaps back to its preformed curved configuration after removal of the elongated piercing element 12. Such a curved portion makes sieve portion 13 easily manipulatable in the body cavity by twisting catheter 1. The catheter including the sieve portion, however, is laterally flexible to bend and flex as the patient moves so first end 2 of catheter 1 does not jab into the patient.
The second end 3 of catheter 1 has, in the absence of elongated piercing element 12 within the bore of catheter 1, an L-shaped tubular member 14 directing fluid flow laterally from a second end of catheter 1. Previous to this L-shaped tubular means associated with the catheter, a drainage tube leading longitudinally from the second end 3 of the catheter would frequently kink, thus shutting off flow to the catheter. For years people have tried to overcome this problem by taping the drainage tube 30 in a large loop, or constructing a makeshift splint from tongue depressors taped to tubing leading from the catheter to a fluid supply source. I have eliminated these problems by providing an L-shaped tubular member fixed to the second end 3 of the catheter 1. If the catheter extends outwardly from the abdominal Wall a considerable distance, as in a slender patient, the physician can bring the second end 3 closer to the abdominal wall by cutting off any extra length of the catheter 1 and attaching L-shaped tubular member 14 to the severed end.
Referring to FIGURE 4, we turn now to a modification of my invention which is particularly adapted for use in thorax paracentesis, i.e. thoracentesis. In a thoracentesis procedure, a conduit goes through the chest wall into the chest cavity, and it is highly critical that the conduit be airtight. If air leaks into th econduit he lungs can collapse, and the patient cannot breathe. The paracentesis instrument shown in FIGURE 4 is the same as that shown in FIGURE 1 with the added feature of a seal 15 at the second end of the catheter which slidingly seals the elongated piercing element 12 to the catheter 1. Fluid enters and exits through a side channel 18 communicating with the bore of the catheter 1 between sieve portion 13 and second end 3 of the conduit element. Preferably, side channel 18 has a valve 26 therein to prevent any air or liquid from bing unintentionally drawn into the chest cavity. A valve 19 can also be placed in the catheter 1 adjacent its second end 3 so elongated piercing element 12 need not remain in seal 15 after insertion of the catheter through body wall 16. Valve 19 would stop any leakage through the punctured hole in seal 15. Valves 26 and 19 may be combined in a single valve element at the fork of catheter 1 and side channel 18.
The tubular conduit element or catheter 1 is laterally flexible for manipulation inside a body cavity without injuring the patient while elongated piercing elemnt 12 is much stiffer and supports the catheter upon piercing a body wall 16. Tubular cathter 1 can be of a thermoplastic material such as nylon, polypropylene, polyethylene, or polyvinyl chloride. Elongated piercing element 12 may be solid and of metal or of a stiff thermoplastic material such as nylon or Delrin.
To illustrate how the medical instrument of my invention operates, I will briefly describe a peritoneal dialysis procedure. With the elongated piercing element 12 in the bore of catheter 1, as shown in FIGURE 1, a physician pushes the pointed end through the locally anesthetized abdominal wall 16. On piercing the peritoneum layer 20 along the inner surface of the abdominal wall 16, liquid enters space 7 through ports 4 and wells up within catheter 1. The physician can then withdraw the pointed end 5 back into catheter 1 slightly so as not to injure any of the organs in the abdominal cavity during deeper insertion. After completely inserting the sieve portion 13 of the catheter 1, and removing elongated piercing element 12, the physician cuts off an excess length of the catheter 1 extending outwardly from the abdominal wall 16. Next he attaches L-shaped tubular means 14 to the severed end of catheter 1. A source of dialyzing solution is then conncted through a tube 30 to L-shaped tubular means 14, and peritoneal dialysis begins.
For illustrative purposes I have used specific examples to describe my invention. However, it is understood that persons skilled in the art can make certain modifications to these examples without departing from the spirit and scope of this invention.
1. A paracentesis instrument for puncturing a patients body wall to provide a fluid channel communicating with a body cavity, which instrument comprises:
(a) a generally constant diameter, laterally flexible, thermoplastic tubular conduit element having a wall surrounding a bore extending between first and second ends of the conduit element, said wall having a generally cylindrical internal wall surface and a generally cylindrical external wall surface;
(b) said conduit element having a sieve portion substantially immediately adjacent its first end with a series of ports through its wall to provide fluid flow into and out of said bore through said ports;
(c) a removable, straight and rigid, elongated piercing element within the bore of the conduit element, one end of the piercing element being pointed and extending slightly beyond the first end of the conduit element, the opposite end of the piercing element extending from the second end of the conduit element, said piercing element having a single solid homogeneous rod-like element having a substantially uniform cross-section and extending between opposite ends of the conduit element and engageable with portions of the conduits internal wall surface between the sieve portion and the second end of the conduit element;
((1) handle means on one end of the piercing element,
which handle means abuts the conduit elements second end and extends both longitudinally and laterally beyond the conduits second end, the rigid piercing elements length between its handle and its pointed end being approximately the same as the conduit elements length so the first end of the conduit element is very near the pointed end of the piercing element when the conduit element has its second end abutting said handle means;
(e) which conduit element has a larger internal diameter than the piercing elements external diameter to provide an axially extending space therebetween extending the length of said rod; and
(f) which conduit element has flanges surrounding said ports, which flanges extend inwardly from the internal wall surface terminating in spaced relation from the outer surface of said piercing element to maintain the elongated piercing element spaced from the internal wall surface of the conduit in the area of the sieve portion for permitting free movement of said piercing element in said conduit element, and permitting free movement between the inner surface of said conduit and the outer surface of said piercing element while the piercing and conduit elements are embedded in a body cavity.
2. A paracentesis instrument as set forth in claim 1 wherein the conduit has a preformed curve straightened by said elongated piercing element, said conduit element returning to a curved configuration upon removal of the elongated piercing element.
3. A paracentesis instrument as set forth in claim 1 wherein the elongated piercing element is slidably sealed to the conduit element by a resilient member near the conduit elements second end, and wherein a side channel communicates with the bore of the conduit element between the second end and said ports.
3,459,188 5 6 4. A paracentesis instrument as set forth in claim 3 FOREIGN PATENTS wherein the side channel has a valve. 1 006 845 1/1952 France References Cited OTHER REFERENCES UNITED STATES PATENTS 5 Lancet, October 1964, pp. 792-94. 2,458,305 1/1949 Saunders 128-348 Lancet, May 15, 1965, pp. 1047-49. 2,836,180 5/1958 Strauss 12s -214.4 3,030,953 4/1962 Koehn 12s- 214.4 DALTON TRULUCK, Primary Examiner 3,064,653 11/1962 Coanda 128-348 3,312,220 4/1967 Eisenberg 128214.4 10
3,313,299 4/1967 Spademan 12s-214.4 123-214, 221