Visually assisted entry of a Veress needle with a tapered videoscope for microlaparoscopy
A Veress needle is modified to receive a forward-looking miniature videoscope through the cannula of an insufflation tube of the Veress needle. The modified instrument enables direct viewing of progress of the instrument through tissue to the peritoneal cavity of a patient, for proper location of the needle and insufflation of the cavity via the needle. The videoscope has an elongated shaft of smaller diameter than the cannula of the insufflation tube for passage of insufflation gas with the scope in place. In another embodiment a needle is fitted with a miniature videoscope to provide the same function, with the needle's cannula serving as an insufflation tube.
1. In combination, a Veress needle for facilitating pneumolaparoscopic surgery and a visualization stylet, comprising:
the Veress needle having a sharp puncturing tip at a distal end of a hollow needle within which a spring-loaded insufflation tube is positioned, the hollow needle being configured for insertion into a patient to form a cavity for the pneumolaparoscopic surgery,
the insufflation tube having an essentially flat distal end through which gas can be delivered by the Veress needle and being retractable against spring pressure into a lumen of the hollow needle when the Veress needle is pushed against a surface,
the visualization stylet having a distal stylet end and having a proximal handle,
the stylet having an elongated stylet shaft extending from the handle and sized to be inserted through a proximal end of the Veress needle and into the insufflation tube and out through the distal end of the Veress needle and the insufflation tube by positioning the visualization stylet using the handle, the elongated stylet shaft having a significantly smaller outside diameter than an inside diameter of the insufflation tube throughout the length of the stylet shaft except at said distal stylet end wherein the stylet shaft is of a larger diameter substantially filling the insufflation tube within the Veress needle,
the visualization stylet being a miniature videoscope, with a digital video camera and lens system positioned centrally at a blunt distal tip and a connecting cable extending from the camera proximally through the elongated stylet shaft for connection to image processing and display equipment,
illumination means at said blunt distal tip of the stylet shaft positioned adjacent to and alongside the camera and lens system, and
said smaller outside diameter of the stylet shaft being sufficiently small in diameter as to leave a clearance between the stylet shaft and the insufflation tube, the clearance having an area sufficient to provide a fluid flow path,
whereby the Veress needle can be inserted through tissue of a patient with the distal stylet end of the visualization stylet just inside the distal end of the Veress needle and inside the insufflation tube to provide video images as the Veress needle is advanced through tissue layers, and whereby, once a desired position for insufflation has been reached with the Veress needle, the distal stylet end can be pushed distally to extend the distal stylet end out from the distal end of the Veress needle, so that the larger-diameter end portion distal stylet end of the stylet shaft is removed from the insufflation tube and insufflation gas can be delivered through the insufflation tube of the Veress needle to open a cavity for pneumolaparoscopic surgery on the patient.
2. The combination defined in claim 1 , wherein the stylet shaft includes a taper at said distal stylet end from the smaller outside diameter to the larger outside diameter.
3. The combination defined in claim 1 , wherein the digital video camera at said blunt distal tip has an area no larger than about 1.0 sq. mm.
4. The combination defined in claim 1 , wherein said clearance has a minimum area of about 1.5 sq. mm.
5. The combination defined in claim 1 , wherein the hollow needle of the Veress needle has an outside diameter no larger than 2.1 mm.
6. The combination defined in claim 1 , wherein the illumination means comprises a distal end of at least one optical fiber, with a light source at a proximal end of the fiber to direct light through the fiber.
7. The combination defined in claim 1 , wherein the illumination means comprises an LED, connected to a power source via said connecting cable.
8. The combination defined in claim 1 , wherein the digital video camera at said blunt distal tip has an area no larger than about 1.6 sq. mm.
9. The combination defined in claim 1 , wherein said clearance has an area of at least 1.0 sq. mm.