Prevention of Conversion in Posterior Retroperitoneal Adrenalectomy by Measuring Preoperative Anatomical Conditions

Study Overview
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Brief Summary
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With our retrospective study the investigators show the limitations of the posterior retroperitoneal adrenalectomy by analyzing anatomical parameters. The investigators compared the data from one patient who underwent a conversion with 13 patients without a conversion. Furthermore, they explored the influence of these parameters on the operation time and excluded the patient who had a conversion from this analysis. The investigators hypothesize that by determining anatomical characteristics on cross-sectional imaging (CT or MRI), they can show the limitations of the posterior retroperitoneal adrenalectomy to prevent patients from being converted to lateral transperitoneal adrenalectomy.

Detailed Description
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Minimally invasive adrenalectomy has become the gold standard for the surgical treatment of small, benign adrenal lesions. In addition to the common laparoscopic lateral transperitoneal adrenalectomy, the posterior retroperitoneal adrenalectomy is becoming increasingly important. To date, there is no consensus regarding the preferred approach in the resection of benign adrenal tumors. A comprehensive adrenal tumor program should be able to offer both options, however, patient selection criteria for a given approach have not yet been defined. The choice between lateral transperitoneal adrenalectomy and posterior retroperitoneal adrenalectomy is relevant for patients with unilateral tumors < 6-7 cm and without previous abdominal surgery. The aim of this study was to determine the limits of posterior retroperitoneal adrenalectomy using anatomical parameters to enable the preferred access to be chosen preoperatively to prevent conversion. In addition, the investigators describe the relationship between these parameters and the operation time to find a measure of the degree of technical difficulty.

Official Title
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Prevention of Conversion in Posterior Retroperitoneal Adrenalectomy by Measuring Preoperative Anatomical Conditions on Cross-sectional Imaging (CT or MRI)

Conditions
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Adrenal Tumor, Adrenal Mass, Pheochromocytoma, Conn Adenoma, Adrenal Metastases, Adrenal Hyperplasia

Intervention / Treatment
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* Other: Posterior retroperitoneal adrenalectomy (PRA)
* Other: Lateral transperitoneal adrenalectomy (LTA)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients whose adrenal gland was removed with retroperitoneal access Operation was between 01.07.2016 and 31.12.2018 Operation was at the Kantonsspital Aarau Exclusion Criteria: Patients with multivisceral resection

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Non-conversion<br>In 13 patients, 14 posterior retroperitoneal adrenalectomy procedures were successfully completed and form the non-conversion group | Other: Posterior retroperitoneal adrenalectomy (PRA)<br>* Minimally invasive adrenalectomy procedure<br>|
| Conversion<br>Conversion to lateral transperitoneal adrenalectomy was necessary in 1 patient after starting posterior retroperitoneal adrenalectomy. | Other: Posterior retroperitoneal adrenalectomy (PRA)<br>* Minimally invasive adrenalectomy procedure<br>Other: Lateral transperitoneal adrenalectomy (LTA)<br>* During posterior retroperitoneal adrenalectomy, the failure to progress or the difficulty of creating or maintaining a pneumoperitoneum are reasons why conversion occurs.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sagittal distance between the dorsal border of the adrenal gland and the 12th rib tip | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Sagittal distance between the dorsal border of the adrenal gland and the 12th rib tip, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Thickness of retroperitoneal fat | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Defined as the largest distance between the kidney parenchyma and the posterior abdominal wall at the level where the renal vein joins the vena cava inferior. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Posterior Adiposity Index | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Distance from skin to renal parenchyma through the 12th rib tip. The larger the distance, the larger the index. The scale ranges are open. | The measurement of the parameter from the cross-sectional image was performed in the period from 19.11.2018 - 04.02.2019. | 
| Longitudinal distance between the upper pole of the kidney and the inferior border of the adrenal gland. | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Longitudinal distance between the upper pole of the kidney and the inferior border of the adrenal gland, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Longitudinal distance between the superior border of the adrenal gland to the 12th rib tip. | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Longitudinal distance between the superior border of the adrenal gland to the 12th rib tip, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Longitudinal distance between the 12th rib and the iliac crest | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Longitudinal distance between the 12th rib and the iliac crest, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Sagittal thickness of the subcutaneous layer above the 12th rib tip | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Sagittal thickness of the subcutaneous layer above the 12th rib tip, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Sagittal thickness of the subcutaneous layer above the iliac crest | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Sagittal thickness of the subcutaneous layer above the iliac crest, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Thickness of the subcutaneous layer above the 12th rib tip | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Thickness of the subcutaneous layer above the 12th rib tip, measured on the straight line to the center of gravity, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Sagittal thickness of the subcutaneous layer between the center of gravity and the lateral border of the body | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Sagittal thickness of the subcutaneous layer between the center of gravity and the lateral border of the body, measured at the level of the 12th rib tip, mm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Tumor size | Measurement of preoperative anatomical conditions on cross- sectional imaging (CT or MRI). Tumor size, cm. | The measurement was performed in the period from 19.11.2018 - 04.02.2019. | 
| Operative time | Duration of adrenalectomy. Data were extracted and analyzed from the hospital information system. | The data were collected between 19.11.2018 and 04.02.2019. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body-Mass-Index | Value derived from the mass (weight) and height of a person. Data were extracted and analyzed from the hospital information system. | The data were collected between 19.11.2018 and 04.02.2019. | 
| The side of the adrenal gland that was removed | Side of the removed adrenal gland (left, right, bilateral). Data were extracted and analyzed from the hospital information system. | The data were collected between 19.11.2018 and 04.02.2019. | 
| Previously performed abdominal surgeries taken from the hospital information system | Previous abdominal operations with opening of the abdominal cavity which give an indication of adhesions.Data were extracted and analyzed from the hospital information system. | The data were collected between 19.11.2018 and 04.02.2019. | 
| Age | Age at adrenalectomy. Data were extracted and analyzed from the hospital information system. | The data were collected between 19.11.2018 and 04.02.2019. | 
| Sex | Female or Male | The data were collected between 19.11.2018 and 04.02.2019. | 
| Histological diagnosis of the sample from the adrenalectomy | Histological evaluation. Data were extracted and analyzed from the hospital information system. | The data were collected between 19.11.2018 and 04.02.2019. | 
| Imaging | CT or MRI | The data were collected between 19.11.2018 and 04.02.2019. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Adrenalectomy, Minimally invasive surgery, Posterior Retroperitoneoscopic adrenalectomy, Retroperitoneal fat mass