3D Reconstruction: Cloaca and Complex ARMs 2015

The 3D cloacogram procedure evolved from main radiology with awake patients to interventional radiology with 3D imaging capabilities, now combining endoscopy and imaging in a single session.

The 3D rotational technique uses the same technology as 3D angiography, injecting contrast into hollow structures while the camera rotates around the patient to generate images immediately available at a workstation.

Conventional contrast studies done in main radiology typically provide only AP and lateral views with overlapping structures that are difficult to decipher.

The 3D technique allows precise measurement of the common channel without the foreshortening error inherent in external ruler placement used in conventional imaging.

Nationwide Children's Hospital has the same interventional radiology system with endoscopy in the IR suite, allowing comparison of endoscopic and 3D reconstructed measurements.

3D reconstruction provides useful information for complex decision-making, particularly in determining whether the vagina will reach and the spatial relationship with the rectum, guiding the choice between laparoscopic versus perineal approach.

The radiation dose from a 3D rotational study is very similar to a conventional cloacogram because fewer lateral and frontal static images are needed.

MRI cloacograms lose the real-time capability of seeing what structures fill during injection and significantly increase anesthesia time compared to fluoroscopic techniques.

The radiologic measurements of common channel length have become accurate to within millimeters and now reliably match intraoperative measurements (e.g., 3.5 cm radiologically corresponds to 3.5 cm intraoperatively).

Baseline renal bladder ultrasound is the preferred method for identifying upper and lower urinary tract abnormalities in newborns with cloacal malformations.

Pelvic ultrasound is used primarily to identify fluid accumulation in the vagina or vaginas (hydrocolpos), which guides the timing of drainage therapy.

Placement of a catheter into the common channel for VCUG is challenging because it may enter any of three organ systems (bladder, vagina, or distal colon), making interpretation unreliable without endoscopic guidance.

High-grade vesicoureteral reflux is not commonly identified in cloacal malformation patients; when present, it is typically mild reflux warranting observation rather than intervention.

In the neonatal period, the priority is to identify hydronephrosis, megaureters, and hydrocolpos that may compress the ureters, rather than obtaining precise anatomic detail of the cloaca.

Neonatal endoscopy may not add much diagnostic value and risks traumatizing the tiny common channel structure.

The recommended neonatal approach is to decompress the GI tract with colostomy, drain hydrocolpos if present, and re-evaluate urologic status 48 hours later before making further decisions.

Nephrostomy, ureterostomy, and vesicostomy are not indicated in most neonatal cloacas; vesicostomy may be needed only in cases with obstruction in the common channel.

Decompressing hydrocolpos alone often resolves the urologic picture, changing the clinical status significantly within 48 hours.