Surgery – Means for introducing or removing material from body for... – Material introduced into and removed from body through...
Reexamination Certificate
2002-04-03
2003-07-15
Casler, Brian L. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Material introduced into and removed from body through...
C095S284000, C055S414000
Reexamination Certificate
active
06592543
ABSTRACT:
BACKGROUND
The present invention pertains to the field of the regulation of fluid being expelled from a surgical site. More particularly, the invention relates to a fluid flow regulator, which when used, regulates the flow of fluid from the surgical site and serves as a passive smoke evacuation system for a pressurized surgical site.
Minimally-invasive surgical procedures such as laparoscopic or endoscopic surgery have become increasingly common due to the fact that the procedures generally result in shorter recovery times, less side effects including secondary infections, shorter operating durations, and reduced costs. The term “endoscopic” as used herein encompasses arthroscopic, laparoscopic, hysteroscopic, thoracoscopic or any other similar closed surgical procedures performed with instruments inserted through small, artificially created openings or portals in the patient.
In conventional laparoscopic procedures, a first minimally-invasive surgery access port is formed in the patient's abdomen using a Veress needle to puncture the lapra or abdomen. An insufflator gas such as carbon dioxide is injected into the abdomen to distend the pneumoperitoneum, thereby creating an air space or cavity in proximity to the organs on which the surgical operation is to be performed. The cavity provides the work space necessary for the surgeon to maneuver the surgical instruments and endoscope, which are typically introduced into the surgical site through other access ports created by the surgeon.
The insufflation gas is forced into the surgical site such as the abdominal cavity under pressure by an insufflation device. A number of insufflation devices have two modes of operation, initiation mode and maintenance mode. The initiation mode pumps gas at a high rate in order to quickly distend the pneumoperitoneum. In the maintenance mode, the insufflation gas is pumped at a rate up to a maximum pressure to replace the amount of gas lost during the procedure. Many insufflation devices are capable of delivering a maximum flow rate of approximately 16 to 25 liters per minute.
The maintenance pressure held at the surgical site by the insufflation device will vary depending on the insufflation gas and the patient's weight for example. An obese patient will require a higher abdominal pressure in order to distend the pneumoperitoneum the same distance as that of a thinner patient.
Immediately after the pneumoperitoneum is first distended, an endoscope coupled to a television monitor is inserted into the abdominal cavity to visualize the interior of the surgical entry. In the case that the insertion of the trocar penetrates or punctures a major blood vessel, medical intervention including conventional invasive surgery may be required to control the hemorrhaging.
In the absence of exigent circumstances, the endoscope remains in the portal which is conventionally dedicated for that instrument. Additional portals are created to provide access for other surgical instruments including probes and other surgical devices that are individually inserted through other cannulas.
Lasers, electrocautery devices, and ultrasonic scalpels are often used during surgery to cut, cauterize, ablate, or vaporize tissues inside the abdomen. The application of the devices create “surgical smoke” in the distended cavity as an unintended though not unexpected byproduct. Surgical smoke generally refers to gases or aerosols that may contain toxins, particulate matter, irritants, viable cells and viruses, water vapor, and other undesirable contaminants. Inside the abdominal cavity, the surgical smoke present a health risk to the patient and complicates the surgical procedure. In particular, the surgical smoke may be absorbed by the patient through the pneumoperitoneum and will obscure the surgeon's visibility of the surgical field. Outside the patient, the smoke poses a health risk to the surgical personnel if not properly filtered.
There are a number of prior art devices for evacuating the surgical smoke from the cavity and filtering any gases discharged into the surgical room. Some of these prior art systems for smoke evacuation use a smoke filter in combination with an external source of vacuum used to draw the smoke laden insufflation gas from the surgical site through the filter. The source of vacuum may be provided by a wall outlet available in the surgical rooms or a dedicated machine capable of regulating the fluid flow rate though the filtration system. Smoke evacuation systems using a wall vacuum are unsuitable for most surgical applications because they require lengthy and obtrusive rubber hoses running from the patient and periodic intervention by the surgeon to balance the flow of insufflation gas pumped into or aspirated from the patient. The second class of smoke evacuation systems, including stand-alone and dedicated machines, requires a substantial capital investment to both purchase and maintain the equipment.
Still another category of prior art smoke evacuation systems includes strictly passive filtration systems that avoid the use of vacuum. U.S. Pat. No. 6,110,259 to Schultz and PCT application no. PCT/US99/28204 to Booth, which are both incorporated in their entirety by reference, operate solely in response to the pressure differential created by the surgical site and ambient air.
Schultz discloses a smoke filter and fluid conduit operatively coupled to a pressurized surgical site wherein the fluid flow rate is determined by the inherent properties of the filter media and the ‘substantially unobstructed fluid flow path’ through the fluid conduit. As an advantage, Schultz asserts that his invention eliminates the dependency on a vacuum source and combination of ‘flow restrictors or reducers’ and filters. Moreover, the Schultz smoke evacuation system consisting only of a filter and fluid conduit teaches away from the use of multiple, in-line structures (filters, resistors, etc.) for stepping or reducing suction whose presence would avoid the simplicity cited as an advantage.
Notwithstanding the fluid regulatory properties of the filter media, the Schultz smoke evacuation system requires a stopcock to start and stop the fluid flow through the system. The stopcock remains in the closed position prior and during the application of the laser, electrocautery device, or ultrasonic scalpels, thereby preventing the escape of any smoke from the surgical site. The stopcock is only opened after the surgical site becomes has saturated with smoke that visibility is impaired. The stopcock is then turned to the full open position, at which point the pneumoperitoneum is rapidly deflated and the surgical smoke passed through the filter. Prior to any further surgery, the stopcock is again closed and the pneumoperitoneum re-pressurized by insufflation device, which may take uncomfortably long period of time. The process of evacuating the smoke and reinflating the pneumoperitoneum may be repeated numerous times during the laparoscopic procedure.
A significant disadvantage of the Schultz system is that the ability of the surgeon to visualize the surgical site and proceed with surgery is significantly hampered during the period that the smoke is evacuated and the pneumoperitoneum distended again. Not only is it inconvenient, but is poses a risk to the patient. More specifically, the surgeon is prevented from observing or intervening on behalf of a patient that is experience internal hemorrhaging, for example, while repeatedly inflating and evacuating the pneumoperitoneum.
Booth discloses a flow control device interposed between the surgical site and the smoke evacuation filter. Although the character of the flow control device is unspecified it would appear to be a form of stopcock consistent with the mechanism shown by Schultz. As such, the Booth device suffers the same drawbacks as the Schultz invention.
SUMMARY
The present invention overcomes the limitations of the prior art with a fluid flow regulator which, when operatively integrated into a passive smoke evacuation system, regulates the flow rate to permit the
Ekinaka Michael
Maaskamp Armand
Wortrich Theodore S.
Casler Brian L.
Hoffman Michael
Surgin Inc.
The Soni Law Firm
Thissell Jeremy
LandOfFree
Fluid flow regulator for a smoke evacuation system and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fluid flow regulator for a smoke evacuation system and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluid flow regulator for a smoke evacuation system and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3051792