Short summary

Surgery is a central part of the treatment for ovarian cancer. Postoperative complications occur in over one third of cases and can delay the start of chemotherapy, potentially negatively impacting the patient's survival chances. During surgical procedures, diffuse fluid retention in the body can occur, as well as fluid accumulation in body cavities, such as the abdominal and pleural cavities. This fluid buildup can lead to complications, including breathing difficulties and infections. The aim

Rationale

The purpose of the project is to investigate the relationship between perioperative fluid retention in the body and complications in patients with ovarian cancer. Denmark has the second-highest incidence of ovarian cancer in the world, with 551 cases annually (1). Ovarian cancer is primarily asymptomatic in its early stages, and at the time of diagnosis, 70-80% of women will have local spread or advanced disease (FIGO stage II-IV) (2). The primary treatment for ovarian cancer is surgery. During the primary operation, a total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and peritoneal biopsies are performed. The goal is a macroscopically radical operation, where all visible tumor tissue is removed. The surgery may also involve lymph node removal, peritonectomy, splenectomy, and bowel resection, where either a stoma or anastomosis is created. The procedure typically lasts 2-7 hours, after which most patients are admitted to intensive care. Postoperatively, 6 cycles of adjuvant chemotherapy are offered (3). During the operation, the patient receives large amounts of intravenous fluids to compensate for intraoperative fluid loss (4). Inadequate fluid replacement can lead to hypotension, which may have serious consequences in the form of tissue hypoperfusion of vital organs, such as the kidneys, brain, and heart, potentially being life-threatening (5). On the other hand, overhydration can lead to pulmonary complications and tissue edema, increasing the risk of complications such as anastomotic leakage. Complications occur in 36,3% of the cases (6) and reduce the patients' chances of survival by extending the interval between surgery and the initiation of adjuvant chemotherapy. Therefore, perioperative fluid therapy monitoring is crucial to ensure euvolemia and adequate tissue perfusion to minimize postoperative complications (7). Clinically, it is well known that patients in the early postoperative phase experience overhydration with a weight gain of at least 3-5 kg (SOURCE). Hence, it is of interest to investigate whether there is a correlation between the degree of postoperative fluid retention and the complications following surgery for ovarian cancer.

Description of the cohort

The study is conducted as a retrospective cohort study, where we collect data from medical records of all patients who underwent surgery for ovarian cancer at Odense University Hospital (OUH) in the period 2021-2024. Data will be collected on approximately 480 patients. Data is entered into REDCap, a secure database for building and managing data. Statistical analysis will then be performed using the program Stata. We collect the following variables about the patients: age at the time of surgery, disease stage (FIGO stage), comorbidity (Charlson Index), general condition (ASA score), performance status, BMI, extent of the procedure (Surgical Complexity Score), complications (Clavien-Dindo classification), length of stay, readmission, blood loss, duration of surgery, and whether HIPEC treatment was administered. Pre- and postoperatively, we record daily weight, albumin, hemoglobin, erythrocyte volume fraction (EVF), eGFR, creatinine, leukocytes, and CRP. The serum biomarker albumin and weight changes are used as indicators of perioperative fluid accumulation. The primary endpoint is a complication-free postoperative course (no complications <2 on the Clavien-Dindo classification) and the time to initiation of adjuvant chemotherapy after surgery (<30 days). The secondary endpoints are the length of stay in the intensive care unit and the total postoperative hospital stay. We exclude women who have unresectable disease, underwent surgery for palliative purposes, or have missing data, such as incomplete anesthesia records and lack of information on fluid intake/loss.

Data and biological material

We use data from the patient journal.

Collaborating researchers and departments

Department of Gynaecology and Obstetrics (Odense Hospital)

• Anne Sofie Jul elben
• Lone Kjeld Petersen