Letter to the Editor: Ultrasound Detection of the Disconnected Distal Catheter of a Ventriculoperitoneal Shunt in the Pelvic Region

Dear Editor,

Few papers have been published concerning ultrasound detection of foreign bodies and medical devices in several clinical fields. This encouraged us to add our ultrasound finding in a patient with displaced distal catheter of the ventriculoperitoneal (VP) shunt into the pelvic region. Although many VP shunt complications have been described in the literature, intraabdominal complications are quite rare. Obstruction and infection are reported as the most common, while displacement of the device seems to be less defined although its sequelae can be rather severe (Vinchon M, et al. Childs Nerv Syst 2012; 28: 847 – 854). In our case, a 30-year-old patient was referred to ultrasound examination due to periodic, irregular diffuse pain in the lower abdomen not associated with menstrual bleeding. The patient had a diagnosis of septo-optic dysplasia and a medium-pressure VP shunt with a Pudenz valve had been inserted at the age of 2 for the treatment of communicating hydrocephalus. Current abdominal examination showed mild, diffuse tenderness with voluntary guarding but without rebound, while pelvic examination revealed normal external and internal genitalia. A transvaginal ultrasound showed a normal uterus with both ovaries. Abundant free fluid was noted in the peritoneal cavity and the amount of fluid distension fluctuated during the study. In the rectouterine pouch the transverse section of the tube recognized as the distal part of the VP shunt was revealed ([Fig. 1]). The best visualization of the VP shunt was achieved by three-dimensional and four-dimensional transvaginal techniques and processing by a program from obstetric software ([Fig. 2]). The shunt tip initially visualized in the vesicouterine excavation changed its position after urination and later was found in the rectouterine pouch. We think that it is of great importance to diagnose the disconnection and migration of the free distal catheter of the VP shunt in order to prevent possible damage to the vital organs. For that purpose transvaginal and abdominal ultrasonography has been shown to be a reasonable choice due to its diagnostic possibilities and decreased costs compared to other techniques. Sonography has already been shown to be a valuable tool for the localization of abdominal fluid collections and the precise determination of the distal part of the VP shunt (Al-Duraibi S. Int J Health Sci 2014; 8: 107 – 111). In addition, ultrasound is a useful technique for the evaluation of the extent of ascites and the dynamics of its collection, while three-dimensional sonography allows demonstration of the coronal plane perpendicular to the transducer face enabling more precise localization of the foreign body and better identification of surface irregularities (Benaceraff BR, et al. Ultrasound Obstet Gynecol 2009; 34: 110 – 115). In our case we even used obstetrical four-dimensional ultrasound which allowed improved visualization of the VP shunt which represents professional invention showing us that we should not be limited by manufacturer instructions. This case report is also an affirmation that gynecologist should investigate the entire patient medical history since many pathological conditions could have an impact on the pelvic cavity and female genital organs.

Fig. 1 Transvaginal ultrasound picture showing free collection of fluid in the rectouterine pouch with transverse section of the disconnected distal part of ventriculoperitoneal shunt.

Fig. 2 Four-dimensional ultrasound picture of the uterus and distal part of ventriculoperitoneal shunt positioned in the vesicouterine pouch.