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NCT Number: NCT04584866

Semi-sitting Versus Supine Position in Endoscopic Skull Base Surgery

This study is to prospectively compare the standard supine (control group) and the semi-sitting position (head elevation of 30°; intervention group) in endoscopic endonasal pituitary surgery.

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Key information

Conditions

Pituitary Adenoma Brain Diseases Brain Neoplasms Central Nervous System Diseases Central Nervous System Neoplasms Endocrine Gland Neoplasms Endocrine System Diseases Hypothalamic Diseases Hypothalamic Neoplasms Neoplasms Neoplasms by Site Nervous System Diseases Nervous System Neoplasms Pituitary Diseases Pituitary Neoplasms Supratentorial Neoplasms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Neurosurgery, University Hospital Basel

Basel, 4031, Switzerland

About this study

The endonasal endoscopic approach (EEA) for pituitary surgery is standardly performed with the patient in supine position (SP). The semi-sitting position (SSP) is routinely used for the traditional microscopic transsphenoidal approach and also for posterior fossa surgery. The SSP results in lower intracranial pressure when compared to the supine position due to decreased venous congestion. As a result, intraoperative bleeding may be reduced, potentially leading to decreased surgical morbidity and improved surgical workflow. Studies during endoscopic sinus surgery have shown a significant reduction of blood loss when the patient is placed in a reverse Trendelenburg position with a head elevation of 30°. This study is to prospectively compare the standard supine (control group) and the semi-sitting position (head elevation of 30°; intervention group) in endoscopic endonasal pituitary surgery.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with a presumed pituitary pathologies who are suitable for endoscopic endonasal surgical resection

Exclusion criteria

  • Patients with known hemorrhagic or thrombophilic disorders
  • Patients with conditions associated with high central venous pressure: congestive heart failure, pulmonary hypertension, chronic obstructive pulmonary disease (COPD), interstitial lung disease, pregnancy
  • Patients with poor cardiopulmonary condition (unable to perform 4 metabolic equivalents without stopping (climb a flight of stairs))

Treatment and study plan

Endonasal endoscopic pituitary surgery in semi-sitting position

Procedure

Patients will be placed in semi-sitting position. To achieve the semi-sitting position, the patient is placed in supine position. The operating table is then separated and flexed to elevate the torso (angle of 30°). The head, which is fixed in a head clamp, is slightly flexed to bring the floor of the sella right in front of the surgeon and gently rotated toward the operating team.

Endonasal endoscopic pituitary surgery in supine position

Procedure

Patients will be operated in the standard supine neutral position

Primary outcomes

  1. Intraoperative blood loss

    Time frame: Intraoperative

    Intraoperative blood loss, calculated as follow: volume in the suction bag minus volume of rinsing water in Milliliters (ml). The surgery is divided into four steps: 1. endonasal phase, 2. osteodural exposure. 3. sellar stage and 4. skull base defect closure. For each step, the primary outcome will be assessed.

  2. Frequency of interruption of the surgical workflow due to disturbing blood or a bleeding in the surgical field (number)

    Time frame: During surgery

    Frequency of interruption of the surgical workflow due to disturbing blood or a bleeding in the surgical field. This will be assessed by an independent blinded neurosurgeon, who will watch the operative video after the surgery.

Secondary outcomes

  1. Change in intraoperative Mean Arterial Pressure (MAP)

    Time frame: Intraoperative

    MAP will be monitored during the whole surgery using the software Copra ©, which allows a continuous data extraction

  2. Amount of intravenous fluid administered during surgery (ml)

    Time frame: Intraoperative

    Amount of intravenous fluid administered during surgery (ml)

  3. Need for vasoactive drugs (vasopressors) (number)

    Time frame: at Day 1 (day of surgery)

    Need for vasoactive drugs (vasopressors) (number)

  4. Incidence of air embolism (number)

    Time frame: at Day 1 (day of surgery)

    Incidence of air embolism (number)

  5. Operative time (minutes)

    Time frame: During surgery

    Operative time (minutes)

  6. Degree of descent or prolapse of the diaphragma sellae into the sellar cavity

    Time frame: Intraoperative

    Intraoperative assessment of the degree of descent or prolapse of the diaphragma sellae into the sellar cavity (class I to V, according to the classification of Abdelmaksoud et al)

  7. Occurrence of a cerebrospinal fluid (CSF) leak during surgery (assessed by the operating neurosurgeon) (yes/ no)

    Time frame: During surgery

    Occurrence of a cerebrospinal fluid (CSF) leak during surgery (assessed by the operating neurosurgeon)

  8. Surgical ergonomics

    Time frame: at Day 1 (day of surgery)

    Surgical ergonomics assessed by the means of a standardized questionnaire. The surgeon will be asked to rate the intensity of neck and arm discomfort and the frequency of surgical flow interruption due to a suboptimal trajectory of the endoscope and the instruments due to the patient Position (1 = no discomfort, 2 = medium discomfort, 3 = high discomfort).

  9. Incidence of rhinoliquorrhoea (number)

    Time frame: at 3 months after surgery

    Incidence of rhinoliquorrhoea (number)

Sponsors and collaborators

Lead sponsor

University Hospital, Basel, Switzerland

Other

Registry information

Official study title

Semi-sitting Versus Supine Position in Endoscopic Skull Base Surgery (PosESS-Study) - Study Protocol for a Randomized-controlled Single-blinded Superiority Trial

Acronym: PosESS

Important dates

Study start
2021
Primary completion
2024
Study completion
2024
First posted
Oct 14, 2020
Registry last updated
Apr 29, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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