# US 8,540,746 B2 · Cannula for receiving surgical instruments > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,746 B2 - Document ID: US8540746B2 - Status: Granted - Kind: B2 - Application number: 13/615,961 - Filed: 2012-09-14 - Published: 2013-03-14 - Granted: 2013-09-24 - Earliest claimed: 1998-08-20 - Assignees: Zimmer Spine, Inc. - Applicants: Thomas W. Davison; Timothy E. Taylor; Adam Sher - Inventors: Thomas W. Davison; Timothy E. Taylor; Adam Sher - Web page: https://patentgrep.com/patent/US8540746B2 ## CPC - A61B 17/3421: {Cannulas} - A61B 17/0218: {for minimally invasive surgery (A61B17/0281, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence)} - A61B 17/1757: {for the spine} - A61B 17/32002: {with continuously rotating, oscillating or reciprocating cutting instruments} - A61B 17/3439: {with means for changing the inner diameter of the cannula, e.g. expandable (A61B17/3423, A61B17/3431 take precedence; catheters A61M25/0662)} - A61B 17/0293: {with ring member to support retractor elements} - A61B 17/1735: {for rasps or chisels} - A61B 17/282: {Jaws} - A61B 17/29: Forceps for use in minimally invasive surgery - A61B 17/320016: {Endoscopic cutting instruments, e.g. arthroscopes, resectoscopes (A61B10/0233, A61B17/29, A61B17/3207 take precedence)} - A61B 2017/00238: {Type of minimally invasive operation (A61B2017/00805 takes precedence)} - A61B 2017/00261: {Discectomy} - A61B 2017/0046: {with a releasable handle; with handle and operating part separable} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A cannula (10) receives surgical instruments (120) for performing a surgical procedure on a body (130). The cannula (10) comprises a tube structure (12) defining a passage (16) through which the surgical instruments (120) are inserted into the body (130). The tube structure (12) has a proximal end (20) and a distal end (62). The tube structure (12) includes an expandable portion (40) for enabling an increase in the cross-sectional area of the passage (16) at the distal end (62). The expandable portion (40) of the tube structure (12), when expanded, has a conical configuration. ## Claims ### Claim 1 A method of accessing a spinal surgical site in a patient, the method comprising: providing an access device having an elongate body with a proximal end and a distal end and defining a length between the proximal and distal ends, the access device having an outer surface for engaging the body of a patient and an inner surface at least partially defining a passage sized for receiving a plurality of surgical instruments used to perform a surgical procedure, the access device including an actuatable portion that is actuatable between an unexpanded configuration for insertion into the patient and an expanded configuration for retracting tissue to provide an enlarged surgical field at the spinal surgical site, wherein a cross-sectional area of the passage at a first location in the expanded configuration is greater than a cross-sectional area of the passage at a second location, wherein the first location is distal of the second location; providing an actuator configured to move the actuatable portion from the unexpanded configuration to the expanded configuration; inserting the access device into the patient such that the distal end is adjacent the spinal surgical site and the proximal end is outside the patient; moving the access device from the unexpanded configuration to the expanded configuration with the actuator, thereby increasing access to the spinal surgical site; delivering more than one surgical instrument along an entire length of the passage to the spinal surgical site; and removing the actuator from the access device, wherein the access device remains in the expanded configuration. ### Claim 2 (depends on 1) The method of claim 1, wherein the actuator is configured to be inserted into the passage, wherein the step of moving the access device from the unexpanded configuration to the expanded configuration includes engaging the inner surface of the access device with the actuator and applying a radially directed force against the inner surface. ### Claim 3 (depends on 2) The method of claim 2, wherein after the step of moving the access device, the method further comprises removing the actuator from the access device, wherein the access device remains in the expanded configuration. ### Claim 4 (depends on 1) The method of claim 1, further comprising performing a surgical procedure through the access device at the spinal surgical site. ### Claim 5 (depends on 1) The method of claim 1, wherein the access device comprises a first member and a second member moveable relative to each other. ### Claim 6 A method of accessing a spinal surgical site in a patient, the method comprising: providing an access device having an elongate body with a proximal end and a distal end and defining a length between the proximal and distal ends, the access device having an outer surface for engaging the body of a patient and an inner surface at least partially defining a passage sized for receiving a plurality of surgical instruments used to perform a surgical procedure, the access device including an actuatable portion that is actuatable between an unexpanded configuration for insertion into the patient and an expanded configuration for retracting tissue to provide an enlarged surgical field at the spinal surgical site, wherein a cross-sectional area of the passage at a first location in the expanded configuration is greater than a cross-sectional area of the passage at a second location, wherein the first location is distal of the second location; providing an actuator configured to move the actuatable portion from the unexpanded configuration to the expanded configuration; inserting the access device into the patient such that the distal end is adjacent the spinal surgical site and the proximal end is outside the patient; moving the access device from the unexpanded configuration to the expanded configuration with the actuator, thereby increasing access to the spinal surgical site; and delivering more than one surgical instrument along an entire length of the passage to the spinal surgical site; wherein the actuator is configured to be inserted into the passage, wherein the step of moving the access device from unexpanded configuration to the expanded configuration includes engaging the inner surface of the access device with the actuator and applying a radially directed force against the inner surface. ### Claim 7 (depends on 6) The method of claim 6, further comprising the step of removing the actuator from the access device, wherein the access device remains in the expanded configuration. ### Claim 8 (depends on 6) The method of claim 6, wherein after the step of moving the access device, the method further comprises removing the actuator from the access device, wherein the access device remains in the expanded configuration. ### Claim 9 (depends on 6) The method of claim 6, further comprising performing a surgical procedure through the access device at the spinal surgical site. ### Claim 10 (depends on 6) The method of claim 6, wherein the access device comprises a first member and a second member moveable relative to each other.