Do Extraperitoneal Laparoscopic Surgeries Increase Intracranial Pressure?
Condition: Intracranial Pressure Increase
MeSH terms: Intracranial Hypertension
Study type: Interventional

Summary: 
      When the literature is examined, it has been reported in many studies that intracranial
      pressure increases due to laparoscopic procedures performed in the intraperitoneal area. The
      mechanism of increased intracranial pressure (ICP) associated with insufflation is most
      likely due to impaired venous drainage of the lumbar venous plexus at increased
      intra-abdominal pressure. Changes in ICP can be monitored by ultrasonographic measurement of
      optic nerve sheath diameter (ONSD), which is a generally accepted simple, reliable and
      non-invasive ICP measurement technique. In meta-analyses conducted on this subject, it has
      been revealed that ICP elevation during laparoscopy can be observed with a significant
      increase in ONSD in the early (0 30 minutes) and late (30-120 minutes) periods during
      carbondioxid (CO2) pneumoperitoneum.

      However, the effect of laparoscopic procedures performed in the extraperitoneal area on the
      central nervous system is not clear. There is not found any study in the literature comparing
      laparoscopic procedures, especially performed extraperitoneally and transperitoneally, and
      their effects on intracranial pressure.

      The aim of the study compare to laparoscopic cholecystectomy performed in the transperitoneal
      area and (totally extra-peritoneal) TEP inguinal hernia repair performed in the
      extraperitoneal area in terms of intracranial pressure relationship.
    

Detailed description: 
      A total of 60 patients, including 30 patients who underwent laparoscopic cholecystectomy and
      30 patients who underwent TEP inguinal hernia repair between December 2022 and January 2023,
      were included in the study.

      Inclusion criteria: 18-70 years old, ASA (American Society of Anesthesiologists) I-II,
      patients who will undergo laparoscopic cholecystectomy with the diagnosis of symptomatic
      cholelithiasis or TEP due to inguinal hernia.

      Exclusion criteria: patients who were switched to open surgery, glaucoma, corneal disease,
      eye surgery, cerebrovascular disease, any neurological disease, chronic kidney disease, liver
      cirrhosis, and patients whose peritoneum was opened during TEP.

      Anesthesia

      All patients will undergo general anesthesia and will be given Propofol 2 mg/kg and Fentanyl
      2 μg/kg intravenously (IV) for analgesia. Endotracheal intubation will be performed after a
      4-minute injection of 0.1 mg/kg Vecuronium. Anesthesia will be maintained with an oxygen-air
      ratio of 50:50 propofol. For postoperative nausea and vomiting prophylaxis, 4 mg of
      dexamethasone will be given at induction. Intermittent doses of Fentanyl and Vecuronium will
      be given from time to time as needed. At the end of the surgery, the neuromuscular paralysis
      will be reversed with 0.05 mg/kg Neostigmine and 0.02 mg/kg Glycopyrrolate Injection, and the
      patient will be extubated.

      Surgical Method in Patients Undergoing Laparoscopic Cholecystectomy:

      With a mini incision made under the umbilicus, the abdomen will be entered with a 10 mm
      trocar. Pneumoperitoneum will be created with CO2 gas. The intra-abdominal pressure will be
      set to 14 mmHg. Under the guidance of the laparoscope, 1 10 mm trocar from the subxiphoid
      region and 2 more 5 mm trocars from the subcostal region will be inserted. The cystic artery
      and cystic duct will be clipped and cut, exposing the Callot's triangle. The gallbladder will
      then be separated from the liver bed and removed through the abdomen. The CO2 in the abdomen
      will be evacuated and the trocars will be removed. The operation will be terminated by
      closing the fascia defect and the skin.

      Surgical Method in Patients with Totally Extra-peritoneal (TEP) Repair:

      The outer sheath of the rectus muscle will be seen by passing through the skin and
      subcutaneous tissue with a mini incision made from the umbilicus. A 10 mm trocar will be
      placed in the preperitoneal space and CO2 insufflation will be applied. The pressure will be
      set to 14 mmHg. Two more 5 mm trocars will be placed between the umbilicus and the sympisis
      pubis under the laparoscope. The preperitoneal inguinal region will be dissected with a
      laparoscopic dissector and holder. The hernial sac will be released. A 10x15 cm prolene mesh
      will be fixed to cover the femoral, direct and indirect hernia areas. The trocars will be
      removed by evacuating the CO2 gas. The skin will be closed and the operation will be
      terminated.

      Results

      The primary outcome of the study is the comparison of ONSD measurements between patients who
      underwent laparoscopic cholecystectomy and TEP repair.

      Secondary outcomes are age, gender, ASA score, height, weight, comorbidities, heart rate,
      blood pressure, oxygen saturation (SpO2), end tidal CO2 (ETCO2) measurements.

      ONSD measurement:

      ONSD will be performed with transorbital sonography by 2 investigators unaware of the study
      protocol. Transorbital sonography will be performed using an E-CUBE i7 ultrasound system
      (mechanical index, 0.2; thermal index, 0) using a linear 6-13 Hz probe (Alpinion Medical
      Systems, Seoul, Republic of Korea). To prevent eye damage, a sterile occlusion gel will be
      used and gently probed without applying pressure to the eyelid. Ultrasonographic images of
      the area will be obtained at the optic nerve level and the ONSD image will be taken 3 mm
      behind the optic nerve head. The optic nerve sheath will be taken from both eyes at certain
      times, preoperatively (T0), at the end of insufflation (T1), and at the end of the operation
      (T2). The average value of the 3 measurements will be recorded as ONSD. Heart rate (HR),
      blood pressure, SPO2 and EtCO2 will be recorded separately at each time point.

      Statistical analysis The primary aim of this study is to compare the effect of laparoscopic
      surgeries performed in the preperitoneal and intraperitoneal areas on OSD. For clinically
      reliable results, at least 30 subjects in each group had to detect a difference of 0.3 mm in
      ONSD measurements. Sample size was calculated based on a pilot study. Multivariate
      observational analyzes of all data will be performed. Descriptive statistics will be given
      for hidden variables. Mean and standard deviation will be given for continuous variables,
      frequency and percentage will be given for categorical variables. Mixed effects models will
      be created for constant variables. Group, time and group-time interaction will be evaluated.
      The t-test will be used to measure continuous variables between the 2 groups. When group-time
      interaction is important, least squares means will be compared. Statistical Analysis SAS
      (University Edition 9.4) software will be used for data analysis. A P value of <0.05 will be
      considered significant.
    

Intervention name(s): E-CUBE i7 ultrasound system (Alpinion Medical Systems, Seoul, Republic of Korea)
Intervention type(s): Device
Intervention description(s): ONSD measurement will be made using the E-CUBE i7 ultrasound system.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Diagnostic
Keywords: intracranial pressure; laparoscopic; transperitoneally; extraperitoneal