Imaging methods play an important role in the evaluation of patients undergoing bariatric surgery; the objective of these methods is to provide precise and early diagnosis of complications. This helps to minimize clinical repercussions by allowing quick, appropriate treatment of complications.7,18
Whenever possible, the surgical team should accompany examinations and provide specific details of the procedure employed and any clinical suspicions of each patient. Special care should be taken, together with the surgical team, in respect to the administration of oral contrast, always considering the normal precautions related to venous contrast contraindications (severe allergy, alterations in the renal function, etc.).
Radiological aspects vary depending on the surgical technique utilized (Please see Chapter 14). Knowledge of anatomical–radiological and functional changes is essential in the investigation of possible complications. It is important that the surgeon and radiologist work together as a team for correct image interpretation. Specific, relevant perioperative data may guide the radiological study and minimize false positive or negative reports.
The patient's body weight may be a limiting factor in performing imaging and in the quality of the images obtained, as well as in attaining quality fluoroscopic images. Conventional radiology and computed tomography (CT) equipments have maximum weight limits established by manufacturers, which frequently make the study of superobese patients difficult or even impossible. Additionally, the abdominal diameter may be a limiting factor when performing the examination, specifically with small ring gantry CT devices or the equipment used in conventional upper gastrointestinal studies.
In these patients, the GI series may be performed with the patient in the standing position. The study can also be done in angiography suites, as this equipment often has higher weight limits. Radiology suites with digital acquisition in general allow post-processing adjustments that improve the quality of the images, giving better and quicker final technical results, frequently preventing repeating radiographs.
With CT, details such as removing the mattress from the examination table can improve the quality of the images and reduce artifacts. Other important factors include the utilization of higher kilovolt (kV) and milliampere (mA) settings for image acquisition and the use of softer filters in their reconstruction.
Pulmonary complications frequently occur in patients submitted to bariatric surgery, independent of the technique utilized. Pneumonia and pleural effusions are relatively common, with pulmonary embolism being the most severe complication with the highest mortality rate. Its radiological aspects are similar to those in the nonobese population suffering from pneumonia and will not be described in this chapter.
Ultrasonography is utilized mainly in the preoperative period, to evaluate cholelithiasis and steatosis. Restrictions in the assessment of obese patients are inherent to the ultrasound method. Sound wave penetration is greatly attenuated by the fat layers, making good image acquisition difficult. The presence of dressings, incisions, and drains can also adversely affect the acquisition of quality images. Therefore, it is a method that ...