Closed chest cannulation method and device for atrial-major artery bypass

This method and device permits removal of venous blood from either atrium to a heart lung machine and thereafter returns it (after oxygenation and filtration if needed) to the femoral artery, all in a percutaneous mode. The device includes in combination a guide wire, catheter, transseptal needle, blunt internal obturator approximately the same length as the catheter with a circular barb to secure the catheter in a given longitudinal relationship, an external obturator about the same length as the internal obturator and removably attached thereto, a cannula for passage over the combined obturators and catheter and connectors to attach the cannula to an extracorporeal pump (and oxygenator if needed), which in turn can be connected to the arterial side of a patient's vascular system.

BACKGROUND OF THE INVENTION 
This invention relates to new and useful improvements in percutaneous heart 
bypasses and more particularly seeks to provide a system that can be 
readily available for temporary or emergency cannulation procedures that 
does not require surgical intervention or personnel. The method involves 
essentially cannulae connections to the atria and a femoral or iliac 
artery or aorta by non-surgical personnel and avoids the complications of 
open heart surgery. 
FIELD OF THE INVENTION 
The primary field of this invention is medicine as it relates to assisting 
or taking the place of cardiac output of a weakened or diseased heart and 
particularly during heart surgery, trauma periods accompanying infarction 
or other heart damage, various other procedures, such as angioplasty, or 
waiting for a suitably matched transplant. 
PRIOR ART 
Since the advent of the heart-lung machine, which permits long periods of 
open-heart surgery, many new surgical techniques have been developed, 
including internal heart and heart valve repair, coronary artery bypass, 
natural and artificial heart transplant, etc. During surgical procedures, 
after heart attacks or to supplement chronically weakened hearts, 
procedures have been developed to assist or take over entirely the 
circulation of the blood through the patient's body by partial or complete 
bypass of the heart. 
For temporary and particularly emergency problems such as surgery, evolving 
infarction treatment, or holding a potential transplant patient until a 
natural heart is available, there is a need for simple equipment in a 
hospital that can be quickly connected to the patient without surgical 
intervention and that can provide bypass time to the patient. 
Moreover, when a patient is being treated for an evolving myocardial 
infarction, there is a need to relieve the heart of its work load to the 
maximum possible extent as quickly as possible. In this emergency 
situation, surgical intervention may be avoided if it is possible to 
quickly bypass and thus unload the heart work. 
An earlier attempt and device to acomplish these results was described at 
69 Journal of Thoracic and Cardiovascular Surgery 283 (Feb., 1975). 
SUMMARY OF THE INVENTION 
The invention comprises a method and device to cannulate the natural heart 
during emergency periods with the only connection with the patient being 
through cannulae connected to the atrial and arterial sides of the 
circulatory system. During intermediate steps, an internal blunt obturator 
and associated catheter are sized relative to each other for proper 
introduction and securement to assure that the catheter remains in its 
intended location. This permits more rapid and appropriate response to 
patients' conditions and is readily adaptable to be available and useable 
from a portable hospital cart without surgical intervention or jeopardy to 
the patient. 
The device herein is preferably used in conjunction with the External 
Pulsatile Cardiac Assist Device described in copending application, Ser. 
No. 796,887 but also with other cardiac assist devices. 
Further to the summary of this invention, the specific nature of which will 
be more apparent, the invention will be more fully understood by reference 
to the drawings, the accompanying detailed description and the appended 
claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A cannula is inserted in the right femoral vein and passed to the right or 
left atrium to take blood. If taken from the left atrium, the oxygenator 
(not shown) may be excluded or bypassed, as the lungs will be functioning. 
A roller pump with approximately 80-100 mm Hg suction is used to remove 
the blood from either atria. 
The blood is passed through or around the oxygenator and goes to a pump 
chamber (not shown) and then back to the arterial side at the left or 
right femoral artery or the cannula may be extended past the bifurcation 
into the abdominal aorta. 
This circulation from the roller pump back to the arterial side obviously 
completes the circuit but is not considered part of the present invention. 
An inguinal incision isolates the junction of the right saphenous and 
femoral veins, through which a No. 9 French (69 cm long) polyethylene 
radiopaque catheter 11 is inserted and passed into the right atrium under 
fluoroscopic control with a Seldinger guide wire 12 as an introducer. The 
guide wire 12 is removed and a 70 cm, 17 gauge Ross transseptal needle 13 
inserted through the lumen of catheter 11 and extending slightly beyond 
the catheter tip. The needle is advanced into the right atrium 14 and with 
constant pressure and fluoroscopic monitoring, the atrial septum 16 is 
punctured in the fossa ovalis area. The No. 9F catheter 11 is then 
advanced through the atrial septum 16 over the Ross needle 13 tip 
approximately 4 cm into the left atrium 17 and the Ross needle removed. 
The needle is replaced by an internal obturator 18 having a blunt curved 
distal end 19 and an externally threaded proximal end 21. Adjacent the 
externally threaded proximal end 21 of obturator 18 and extending in a 
distal direction away therefrom is an enlarged section 22, an intermediate 
offset enlarged section 23 and a circular barb 24. The internal obturator 
18 and catheter 11 have relative lengths such that the blunt end 19 
terminates about 1 cm proximally of the catheter distal tip when the 
proximal catheter end is fitted snugly over the circular barb 24 and 
against the enlarged portion 22. The circular barb 24 over which catheter 
11 is secured in the appropriate longitudinal relationship is important. 
Other means to secure the catheter may be used such as an internal flange 
on the proximal end that would be clamped between the internal and 
external obturators when they are threaded together. The enlarged portion 
22 which stops the advance of the proximal end of catheter 11 has the same 
outside diameter as the external obturator 26 which is internally threaded 
at its distal end 27 to mate evenly with the internal obturator. The blunt 
end 19 of the internal obturator, which is proximal to the catheter 11 
tip, is advanced into the left atrium. 
A 27F, 69 cm cannula 28 is then passed over the external obturator 26 and 
catheter 11 which encloses the internal obturator 18 until the tapered tip 
29 having side holes 31 is positioned within the left atrium 17. The 
obturators 18, 26 and the catheter 11 is then removed through cannula cap 
32 and hole 33. The cannula is at least partially radiopaque by stripes or 
otherwise to follow its course under the fluoroscope. The location of side 
holes 31 can be determined by withdrawal of blood which will be bright red 
(oxygenated) from the left atrium 17 and dark red from the right atrium 
14. The proximal end of cannula 28 is now ready for connection to an 
extracorporeal pump unit (not shown) or to be clamped. 
A cut down is performed on the right femoral artery into which a 21F, 12.5 
cm arterial cannula 36 which has a blood line connector 37 and protective 
cap 38 with hole 39. A 17F, 50.5 cm arterial dilator 41 is inserted 
through hole 39. After extension of the dilator to the desired location in 
the femoral artery or upstream to the iliac or aorta, the dilator is 
removed and the cannula connected to the pump or clamped. 
Entry herein has been shown at the most common entry site, the femoral vein 
but other accessible veins large enough for cannula 28 may be used such as 
the subclavian, axillary or internal jugular.