Infiltration cannula

Abstract

An infiltration cannula and method of using the infiltration cannula during an infiltration procedure are disclosed herein. The infiltration cannula has a flexible cannula and a hub. The cannula has a proximal end and a distal end. The cannula also has a plurality of apertures disposed in a pattern about the distal end. The apertures are configured to infiltrate fluid into the subcutaneous or muscle tissue of a patient. The hub is configured to be held by a person performing the infiltration procedure. The hub has a first end and an opposing second end. The first end is attached to the proximal end of the flexible cannula and the second end includes a connector configured to connect to an input source for receiving the fluid to be infiltrated into the subcutaneous tissue of the patient. The fluid flows from the connector, through the hub and into the cannula.

1 . An infiltration cannula for delivering a multi liter amount of fluid to a patient during an infiltration procedure, the infiltration cannula comprising: 
 a rigid stylet;    a flexible tubular cannula with the rigid stylet disposed within the flexible tubular cannula, the flexible tubular cannula comprising: 
 a proximal portion;  
 a distal portion defining a distal end, the distal end being open with a hole, and a tip of the rigid stylet protruding through the hole; and  
 a plurality of apertures disposed in a pattern about the distal portion, the apertures configured to infiltrate the multi-liter amount of fluid into subcutaneous tissue or muscle of a patient;  
   a hub configured to be held by a person performing the infiltration procedure, the hub having a first end and an opposing second end, the first end being attached to the proximal portion of the flexible tubular cannula, the second end comprising a connector for receiving the fluid to be infiltrated into the subcutaneous tissue of the patient, the fluid flowing from the connector, through the hub and into the flexible tubular cannula; and    a continuous flow pump connected to the connector of the hub and operative to continuously deliver fluid through the hub and the flexible tubular cannula at least until a large reservoir of fluid is infiltrated into the patient at a desired site of the patient.    
   
   
       2 . The infiltration cannula as recited in  claim 1 , wherein the tip of the rigid stylet protruding out of the hole is sharp to directly insert the cannula and the stylet through the skin of the patient without a prepatory skin incision.  
   
   
       3 . The infiltration cannula as recited in  claim 2 , wherein the apertures are distributed over about 33% to about 90% of the distal end of the flexible tubular cannula.  
   
   
       4 . The infiltration cannula as recited in  claim 1 , wherein the tip of the rigid stylet protruding out of the hole is blunt such that a prepatory skin incision is required to permit insertion of the stylet and flexible tubular cannula through the skin of the patient.  
   
   
       5 . The infiltration cannula as recited in  claim 4 , wherein the apertures are distributed over about 33% to about 90% of the distal end of the tubular needle.  
   
   
       6 . A method of infiltrating a multi-liter amount of fluid into subcutaneous tissue of a patient, the method comprising: 
 a) inserting a rigid stylet within an open ended flexible tubular cannula until a tip of the rigid stylet protrudes from the open end;    b) inserting the flexible tubular cannula with the rigid stylet disposed therewithin through a patient's skin and into the subcutaneous tissue of the patient at a desired site;    c) removing the stylet from the flexible tubular cannula; and    d) continuously flowing the fluid through the flexible tubular cannula and into the patient via apertures formed along a distal portion of the flexible tubular cannula at least until a large reservoir of fluid has been infiltrated into the patient at the desired site.    
   
   
       7 . The method of  claim 6  wherein the tip of the stylet protruding out of the hole is blunt, and the method further comprises the step of making a prepatory skin incision prior to the inserting the flexible tubular cannula step b).  
   
   
       8 . The method of  claim 6  wherein the tip of the stylet protruding out of the hole is sharp, and the inserting the flexible tubular cannula step b) is accomplished without making a prepatory skin incision.  
   
   
       9 . The method recited in  claim 6 , further comprising inserting the flexible infiltration cannula at a new site in the patient's skin.  
   
   
       10 . The method recited in  claim 6 , wherein at least two flexible infiltration cannulas are inserted into the patient's skin to prevent disruption of the method when one flexible infiltration cannula is removed.  
   
   
       11 . The method recited in  claim 6 , wherein the continuously flowing step includes the step of continuously flowing a local anesthesia fluid.  
   
   
       12 . The method recited in  claim 6 , wherein the method is performed in conjunction with a surgical procedure or therapeutic drug delivery.  
   
   
       13 . The method recited in  claim 6 , wherein the apertures formed on the distal portion of the flexible tubular cannula are distributed about 33% to about 90% of the distal portion of the flexible tubular cannula, and the method further comprises the step of positioning the flexible tubular cannula within the patient until all of the apertures are within the patient and maintaining the flexible tubular cannula in the position until at least a portion of the multi-liter amount of fluid is infiltrated into the patient.  
   
   
       14 . The cannula as recited in  claim 1 , wherein the apertures are arranged in a helical pattern.  
   
   
       15 . The cannula as recited in  claim 1 , wherein the apertures are arranged in a spiral pattern.