<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT01705821</url>
  </required_header>
  <id_info>
    <org_study_id>121194</org_study_id>
    <nct_id>NCT01705821</nct_id>
  </id_info>
  <brief_title>Forces During Skull Base Surgery</brief_title>
  <official_title>Measuring Forces Applied During Skull Base Surgery</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Vanderbilt University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Vanderbilt University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      This study is designed to measure forces applied using standard surgical instruments at the&#xD;
      skull base during resection of skull base lesions. This data will be useful for optimizing an&#xD;
      active canula robot for assisting in skull base surgery. We hypothesize that through&#xD;
      measurement of forces generated during routine endoscopic skull base surgery we will be able&#xD;
      to optimize the canulas of an active canula robot for skull base surgery.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      At some time in their lives, 1 in 5 people will have a pituitary tumor, and 1 in 600 of these&#xD;
      will have the tumor grow large enough (&gt;1 cm in diameter) that surgical resection is&#xD;
      required. Traditionally, surgery to remove pituitary tumors or other tumors at the skull base&#xD;
      requires transcranial or transfacial access. In these approaches, large traumatic, often&#xD;
      disfiguring, openings must be created in the patient's forehead or cheek. Endonasal skull&#xD;
      base surgery reduces invasiveness resulting in less trauma, fewer complications, and shorter&#xD;
      surgical time. However, despite the compelling advantages for the patient, only a small&#xD;
      percentage of skull base surgeries are done endonasally. While exact statistics are not&#xD;
      available, the current best estimate in the literature is that less than 50% and most likely&#xD;
      less than 20% of these tumors are addressed by endonasal surgery.&#xD;
&#xD;
      The endonasal approach is underemployed despite its demonstrated benefits to the patient&#xD;
      because existing surgical instruments have limited dexterity and approach angles, and&#xD;
      simultaneously manipulating several of them through a nostril while performing complex&#xD;
      surgical procedures is so technically challenging that only a small number of expert surgeons&#xD;
      can accomplish it. Even for these experts, mortality rates are non-negligible (0.9%), and&#xD;
      there remain contraindications to the endonasal approach, including occlusion of the surgical&#xD;
      site by delicate and critical neurovascular structures (e.g. carotid arteries, optic nerves),&#xD;
      inability to fully reconstruct the dura due to lack of surgical tool dexterity, and long&#xD;
      surgical duration. All of these contraindications are directly related to limitations in&#xD;
      instrument dexterity and visualization, which motivates the development of a robotic system&#xD;
      for endonasal skull base surgery. Such a robot can potentially increase surgical dexterity&#xD;
      and reduce the technical complexity of the procedure for surgeons, thereby increasing the&#xD;
      percentage of patient who benefit from the endonasal technique.&#xD;
&#xD;
      While many robotic systems have been developed for intravascular interventions as well as&#xD;
      natural orifice surgery though other orifices, comparatively few systems have been targeted&#xD;
      at endonasal surgery. This is likely due to the smaller size of the nasal cavity and nostril&#xD;
      compared to other natural orifices.&#xD;
&#xD;
      For endonasal robots, the limited space available in the nostril opening, combined with the&#xD;
      need to work dexterously within the cavities in the head, implies that instrument shafts must&#xD;
      be small in diameter while enabling dexterous motions of instrument tips. A recently invented&#xD;
      robot design that matches these characteristics is the concentric tube robot concept, which&#xD;
      is also known as by the name active cannula.&#xD;
&#xD;
      A robot suitable for endonasal surgery is being developed (see reference #3), however in&#xD;
      order to optimize this robotic system, intraoperative data must be obtained to determine how&#xD;
      the robot interacts with the patient's tissues. The aim of this study is to modify a&#xD;
      traditional tool used in the operating room to allow determination of forces at the skull&#xD;
      base on both hard and soft tissues. This surgical curette will be used in the standard&#xD;
      fashion during endonasal skull base surgery, however will provide valuable information.&#xD;
&#xD;
      The modified curette will consist of two segments joined by a Nano17 6-axis force sensor.&#xD;
      (Image 1) The force sensor is integrated into the shaft of the instrument (a standard&#xD;
      neurosurgical ring curette) and insulated from the shaft with two polyetherimide (also known&#xD;
      as ULTEM) disks so that no current can be transmitted from the force sensor to the curette.&#xD;
      The sensor is held to the shaft by medical grade adhesive and set screws.&#xD;
&#xD;
      The patients will be recruited from the PIs clinical practice. Informed consent will be&#xD;
      obtained. At the appropriate time during surgery this curette will be used to collect force&#xD;
      date. This force transducer operates at 5V (4.8-9V range). These transducers are commonly&#xD;
      used in medical and dental research (see reference #5).&#xD;
&#xD;
      No additional operating room or anesthesia time will be required.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>October 2012</start_date>
  <completion_date type="Actual">September 2013</completion_date>
  <primary_completion_date type="Actual">September 2013</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Case-Only</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>6-axis force and torque data from routine endoscopic transnasal skull base surgery</measure>
    <time_frame>12 months</time_frame>
    <description>This data will be collected and recorded via a computer interface with our sensorized tool and recorded in standard units for force and torque. We will also look at the variability of forces between patients after collecting this data. The data will be useful in optimizing a robotic system for endonasal surgery as described in the secondary outcome measure.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Percent tumor removal in skull and cadaver studies</measure>
    <time_frame>12 months</time_frame>
    <description>The force and torque data will allow our team of Engineers to optimize our robotic system to be best suited for removing pituitary tumors transnasally. The robot consists of specially designed flexible arms with end effectors that each need to be able to withstand and produce the necessary forces to complete pituitary tumor excision. This will be measured by optimizing our robot based on the findings in the primary outcome measure and then evaluating the robot for efficiency and effectiveness of mock pituitary tumor removal from skull and cadaver specimens. We will investigate percent tumor removal and speed of tumor removal once the robot is optimized.</description>
  </secondary_outcome>
  <number_of_groups>1</number_of_groups>
  <enrollment type="Actual">3</enrollment>
  <condition>Skull Base</condition>
  <condition>Pituitary</condition>
  <condition>Robotics</condition>
  <condition>Endonasal Surgery</condition>
  <condition>Sinus Surgery</condition>
  <arm_group>
    <arm_group_label>Skull Base Surgery Candidate</arm_group_label>
    <description>Patient with a skull base lesion will undergo use of standard surgical curette with force sensor built into shaft. 6-axis force and torque data will be collected during the surgical procedure.</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Use of force sensing surgical curette</intervention_name>
    <description>Use of a standard surgical curette outfitted with an in-line 6-axis force and torque transducer for collection of force data during surgery.</description>
    <arm_group_label>Skull Base Surgery Candidate</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>Removal of pituitary tumor using modified curette</intervention_name>
    <arm_group_label>Skull Base Surgery Candidate</arm_group_label>
  </intervention>
  <eligibility>
    <study_pop>
      <textblock>
        All adult patients undergoing standard endonasal skull base surgery.&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion criteria:&#xD;
&#xD;
          -  Any male or female patient 18-75 years old undergoing endonasal skull base surgery for&#xD;
             a skull base lesion.&#xD;
&#xD;
          -  Competent in decision making process and able to sign a written informed consent form.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
        -Any patient not able to give written informed consent.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>75 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Robert Webster, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Vanderbilt University</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Vanderbilt University Skull Base Center</name>
      <address>
        <city>Nashville</city>
        <state>Tennessee</state>
        <zip>37212</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>United States</country>
  </location_countries>
  <verification_date>December 2014</verification_date>
  <study_first_submitted>October 8, 2012</study_first_submitted>
  <study_first_submitted_qc>October 11, 2012</study_first_submitted_qc>
  <study_first_posted type="Estimate">October 12, 2012</study_first_posted>
  <last_update_submitted>December 8, 2014</last_update_submitted>
  <last_update_submitted_qc>December 8, 2014</last_update_submitted_qc>
  <last_update_posted type="Estimate">December 9, 2014</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Vanderbilt University</investigator_affiliation>
    <investigator_full_name>Robert Webster</investigator_full_name>
    <investigator_title>Assistant Professor</investigator_title>
  </responsible_party>
  <keyword>Skull base</keyword>
  <keyword>Pituitary</keyword>
  <keyword>Robotics</keyword>
  <keyword>Endonasal surgery</keyword>
  <keyword>Sinus surgery</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Pituitary Diseases</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT01705821
org study id: 121194
nct id: NCT01705821
lead sponsor: 
has dmc: No
This study is designed to measure forces applied using standard surgical instruments at the
      skull base during resection of skull base lesions. This data will be useful for optimizing an
      active canula robot for assisting in skull base surgery. We hypothesize that through
      measurement of forces generated during routine endoscopic skull base surgery we will be able
      to optimize the canulas of an active canula robot for skull base surgery.
At some time in their lives, 1 in 5 people will have a pituitary tumor, and 1 in 600 of these
      will have the tumor grow large enough (>1 cm in diameter) that surgical resection is
      required. Traditionally, surgery to remove pituitary tumors or other tumors at the skull base
      requires transcranial or transfacial access. In these approaches, large traumatic, often
      disfiguring, openings must be created in the patient's forehead or cheek. Endonasal skull
      base surgery reduces invasiveness resulting in less trauma, fewer complications, and shorter
      surgical time. However, despite the compelling advantages for the patient, only a small
      percentage of skull base surgeries are done endonasally. While exact statistics are not
      available, the current best estimate in the literature is that less than 50% and most likely
      less than 20% of these tumors are addressed by endonasal surgery.

      The endonasal approach is underemployed despite its demonstrated benefits to the patient
      because existing surgical instruments have limited dexterity and approach angles, and
      simultaneously manipulating several of them through a nostril while performing complex
      surgical procedures is so technically challenging that only a small number of expert surgeons
      can accomplish it. Even for these experts, mortality rates are non-negligible (0.9%), and
      there remain contraindications to the endonasal approach, including occlusion of the surgical
      site by delicate and critical neurovascular structures (e.g. carotid arteries, optic nerves),
      inability to fully reconstruct the dura due to lack of surgical tool dexterity, and long
      surgical duration. All of these contraindications are directly related to limitations in
      instrument dexterity and visualization, which motivates the development of a robotic system
      for endonasal skull base surgery. Such a robot can potentially increase surgical dexterity
      and reduce the technical complexity of the procedure for surgeons, thereby increasing the
      percentage of patient who benefit from the endonasal technique.

      While many robotic systems have been developed for intravascular interventions as well as
      natural orifice surgery though other orifices, comparatively few systems have been targeted
      at endonasal surgery. This is likely due to the smaller size of the nasal cavity and nostril
      compared to other natural orifices.

      For endonasal robots, the limited space available in the nostril opening, combined with the
      need to work dexterously within the cavities in the head, implies that instrument shafts must
      be small in diameter while enabling dexterous motions of instrument tips. A recently invented
      robot design that matches these characteristics is the concentric tube robot concept, which
      is also known as by the name active cannula.

      A robot suitable for endonasal surgery is being developed (see reference #3), however in
      order to optimize this robotic system, intraoperative data must be obtained to determine how
      the robot interacts with the patient's tissues. The aim of this study is to modify a
      traditional tool used in the operating room to allow determination of forces at the skull
      base on both hard and soft tissues. This surgical curette will be used in the standard
      fashion during endonasal skull base surgery, however will provide valuable information.

      The modified curette will consist of two segments joined by a Nano17 6-axis force sensor.
      (Image 1) The force sensor is integrated into the shaft of the instrument (a standard
      neurosurgical ring curette) and insulated from the shaft with two polyetherimide (also known
      as ULTEM) disks so that no current can be transmitted from the force sensor to the curette.
      The sensor is held to the shaft by medical grade adhesive and set screws.

      The patients will be recruited from the PIs clinical practice. Informed consent will be
      obtained. At the appropriate time during surgery this curette will be used to collect force
      date. This force transducer operates at 5V (4.8-9V range). These transducers are commonly
      used in medical and dental research (see reference #5).

      No additional operating room or anesthesia time will be required.
observational model: Case-Only
time perspective: Prospective
measure: 6-axis force and torque data from routine endoscopic transnasal skull base surgery
time frame: 12 months
description: This data will be collected and recorded via a computer interface with our sensorized tool and recorded in standard units for force and torque. We will also look at the variability of forces between patients after collecting this data. The data will be useful in optimizing a robotic system for endonasal surgery as described in the secondary outcome measure.
measure: Percent tumor removal in skull and cadaver studies
time frame: 12 months
description: The force and torque data will allow our team of Engineers to optimize our robotic system to be best suited for removing pituitary tumors transnasally. The robot consists of specially designed flexible arms with end effectors that each need to be able to withstand and produce the necessary forces to complete pituitary tumor excision. This will be measured by optimizing our robot based on the findings in the primary outcome measure and then evaluating the robot for efficiency and effectiveness of mock pituitary tumor removal from skull and cadaver specimens. We will investigate percent tumor removal and speed of tumor removal once the robot is optimized.
arm group label: Skull Base Surgery Candidate
description: Patient with a skull base lesion will undergo use of standard surgical curette with force sensor built into shaft. 6-axis force and torque data will be collected during the surgical procedure.
intervention type: Device
intervention name: Use of force sensing surgical curette
description: Use of a standard surgical curette outfitted with an in-line 6-axis force and torque transducer for collection of force data during surgery.
arm group label: Skull Base Surgery Candidate
intervention type: Procedure
intervention name: Removal of pituitary tumor using modified curette
arm group label: Skull Base Surgery Candidate
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: 18 Years
maximum age: 75 Years
healthy volunteers: No
last name: Robert Webster, PhD
role: Principal Investigator
affiliation: Vanderbilt University
facility: 
country: United States
responsible party type: Principal Investigator
investigator affiliation: Vanderbilt University
investigator full name: Robert Webster
investigator title: Assistant Professor
mesh term: Pituitary Diseases