US-12616359-B2 - Cannula and obturator with a transparent tip with an opaque component

US12616359B2US 12616359 B2US12616359 B2US 12616359B2US-12616359-B2

Abstract

A cannula system and method for accessing a blood mass in the brain. The system comprises a cannula with a camera mounted on the proximal end of the cannula with a view into the cannula lumen and the surgical field below the lumen. A prism, reflector or other suitable optical element is oriented between the camera and the lumen of the cannula to afford the camera a view into the cannula while minimizing obstruction of the lumen. The system may also include an obturator with a small diameter shaft and a large diameter tip which is optically transmissive, so that a surgeon inserting or manipulating the assembly can easily see that the obturator tip is near brain tissue (which is white) or blood (which is red).

Inventors

Peter G. Davis
Ross Tsukashima
Donald Joseph Fuller

Assignees

Rebound Therapeutics Corporation

Dates

Publication Date: 20260505
Application Date: 20230908

Claims (7)

1 . A cannula system for accessing a blood mass in the brain of a patient, said cannula system comprising: a cannula comprising a cannula tube with a proximal end and a distal end and a lumen extending from the proximal end to the distal end; and an obturator comprising an obturator shaft having a proximal end and a distal end, and an obturator tip disposed on the distal end of said obturator shaft, said obturator tip being optically transmissive, said obturator tip having a transverse cross-section closely matching a transverse cross-section of the cannula lumen, said obturator tip having a tapered distal tip, said obturator being slidable within the cannula tube, and positionable within the cannula tube such that the proximal end of the obturator shaft extends proximally out of the cannula proximal end while the tapered distal tip extends out of the cannula tube distal end, wherein the obturator shaft has a transverse cross-section smaller than the lumen of the cannula and smaller than the transverse cross-section of the obturator tip, whereby a proximal surface of the obturator tip is visible from the proximal end of the cannula tube, through the lumen, when the obturator tip is disposed within the cannula such that the tapered distal tip extends out of the cannula tube distal end; and an optically opaque component disposed along a central longitudinal axis of the obturator tip, within the tapered distal tip; wherein the obturator tip comprises a proximal portion, a central cylindrical portion, and wherein the tapered distal tip is a distal conical portion, and the obturator further comprises a bore extending from a proximal-most extent of the proximal portion, distally into the central cylindrical portion, and the distal end of the obturator shaft is disposed within the bore, where the bore has a length such that, when the proximal end of the obturator shaft extends proximally out of the cannula tube proximal end the tapered distal tip extends out of the cannula tube distal end, the bore terminates distally at a point distal to the distal end of the cannula tube.
2 . The cannula system of claim 1 , wherein: the shaft extends distally into the distal conical portion of the obturator tip, and the opaque component comprises the distal end of the obturator shaft.
3 . The cannula system of claim 1 , wherein: the shaft terminates distally in the proximal portion of the obturator tip, and the opaque component is a separate component separate from the obturator shaft.
4 . The cannula system of claim 1 , further comprising: a neuro-navigation stylet having a distal end and a proximal end, said neuro-navigation stylet sized and dimensioned for insertion in a lumen of the obturator shaft; wherein when proximal end of the obturator shaft extends proximally out of the cannula tube proximal end the tapered distal tip extends out of the cannula tube distal end, and the neuro-navigation stylet is disposed within the lumen of the obturator shaft, the distal end of the neuro-navigation stylet terminates distally at a point distal to the distal end of the cannula tube.
5 . The cannula system of claim 4 , wherein: the neuro-navigation stylet terminates distally within the distal conical portion of the obturator tip, and the optically opaque component comprises the distal end of the neuro-navigation stylet.
6 . The cannula system of claim 1 , wherein: the distal conical portion has an apex angle in the range of 35 to 45 degrees.
7 . The cannula system of claim 1 , wherein: the distal conical portion comprises a sharpened distal tip extending distally of the cannula tube to facilitate advancement of the obturator tip through brain tissue.

Description

This application is a continuation-in-part of U.S. application Ser. No. 17/538,244, filed Nov. 30, 2021, pending, which is a continuation of U.S. application Ser. No. 16/788,130, filed Feb. 11, 2020, now U.S. Pat. No. 11,185,218, which is a continuation of U.S. application Ser. No. 16/240,551, filed Jan. 4, 2019, now U.S. Pat. No. 10,555,666, which is a continuation of U.S. application Ser. No. 15/895,295, filed Feb. 13, 2018, now U.S. Pat. No. 10,172,514, which is a continuation of U.S. application Ser. No. 15/576,536, filed Nov. 22, 2017, now U.S. Pat. No. 10,376,281, which is the National Stage of International Application PCT/US2017/047424 filed Aug. 17, 2017, which is a continuation-in-part of U.S. application Ser. No. 15/239,632, filed Aug. 17, 2016, now U.S. Pat. No. 10,172,525, and claims priority to U.S. Provisional Application 62/483,885 filed Apr. 10, 2017. This application is also a continuation-in-part of U.S. application Ser. No. 16/793,690, filed Feb. 18, 2020, pending, which claims priority to U.S. Provisional Application 62/809,445, filed Feb. 22, 2019. The entirety of U.S. application Ser. No. 16/793,690 is incorporated herein by reference. The entirety of U.S. application Ser. No. 17/538,244 is incorporated by reference. FIELD OF THE INVENTIONS The inventions described below relate to the field of minimally invasive brain surgery. BACKGROUND OF THE INVENTIONS Stroke is a common cause of death and disabling neurologic disorder. Approximately 700,000 patients suffer from stroke in the United States every year. Hemorrhagic stroke accounts for 20% of the annual stroke population. Hemorrhagic stroke is due to a rupture of a blood vessel in the brain, causing bleeding into the brain tissue and resulting in a hematoma (a blood mass) in the brain. Prompt removal of the blood mass is necessary to limit or prevent long-term brain injury. Clear visualization and imaging of the blood mass and any surrounding surgical field facilitates removal of the blood mass. Removal and visualization can often be accomplished through a cannula and obturator assembly, placed through a hole drilled in the skull near the site of the hematoma. The site of the hematoma can be accurately identified using a CT scan. To aid in placement of the cannula and obturator assembly precisely at the hematoma, and also to aid in inserting the cannula through a route least likely to damage healthy brain tissue, neurosurgeons use sophisticated and costly stereotactic surgery systems or neuro-navigation systems. These systems depend on previously obtained MRI or CT scans, which may be several hours old, and thus not perfectly reflective of the shape and location of the blood mass at the time of surgery. In these systems, visual confirmation that the cannula distal end is properly positioned can be accomplished only after the obturator has been removed from the cannula. If the distal end has not been accurately placed, the obturator must be re-inserted, and the cannula and obturator assembly must be manipulated, perhaps repeatedly, until, after removal of the obturator, the blood mass is visible. A less sophisticated method, used before these expensive neuro-navigation systems and stereotactic systems became standard and still used where these systems are not available, involves large craniotomies, exploration and direct visual search for a blood mass, extensive tissue dissection, and invasive instrumentation, all associated with high mortality and morbidity. SUMMARY The devices and methods described below provide for improved visualization of the brain during minimally invasive surgery. The device comprises a cannula with a camera mounted on the proximal end of the cannula with a view into the cannula lumen and the tissue within and below the lumen. A prism, reflector or other suitable optical element is oriented between the camera and the lumen of the cannula to afford the camera a view into the cannula while minimizing obstruction of the lumen. The devices including the cannula with a camera mounted on the proximal end of the cannula with a view into the cannula lumen and the tissue within and below the lumen, and optionally a display to display images obtained by the camera, can be used with an obturator comprising a long, small cross-section shaft with a short, large diameter tip which is transparent or translucent. The prism, reflector or other suitable optical element is oriented between the camera and the lumen of the cannula to afford the camera a view of the obturator tip while minimizing obstruction of the lumen. The assembled cannula, camera and obturator can be inserted into the brain of a patient, with the obturator tip used to gently dissect brain tissue to make way for the assembly, as well as obturate (occlude) the distal opening of the cannula. The small cross-section obturator shaft is much smaller than the inner diameter of the cannula, affording a sizable annular or circular space between the shaft and the cannula