Multimodality imaging of the male urethra: trauma, infection, neoplasm, and common surgical repairs

FDG PET/CT in Staging and Response Evaluation of Primary Urothelial Carcinoma of the Urethra

ABSTRACT

Primary urethral urothelial carcinoma is a rare aggressive tumor with a high propensity for local invasion and regional and distal metastases. We describe the usefulness of FDG PET/CT in management of a patient with primary urethral urothelial carcinoma. FDG PET/CT at initial staging showed FDG-avid primary tumor and lymph node metastasis of the left groin, and mild or no activity of the lung metastases due to small size. FDG PET/CT after 4 cycles of chemotherapy showed progression of the primary tumor and lung metastases, partial response of the left inguinal lymphadenopathy, and multiple new sites of FDG-avid metastases.

The pre-operative and post-operative imaging appearances of urethral strictures and surgical techniques

Urethral strictures arise from a variety of etiologies, most commonly either iatrogenic or inflammatory in the anterior urethra and iatrogenic/surgical or traumatic etiologies in the posterior urethra. Diagnosis and treatment planning depend on urethrography, usually performed with a combination of retrograde urethrography (RUG) and voiding cystourethrography (VCUG) to evaluate the anterior and posterior urethra, respectively. While this is most commonly performed fluoroscopically, sonographic urethrography is an alternative, although at the expense of the posterior urethra, it is only visualized using a transrectal approach. In addition to understand urethral anatomy, familiarity with normal periurethral structures is necessary to avoid misdiagnosis, such as Cowper's ducts, the glands of Littré, and the prostatic and ejaculatory ducts. Surgical management depends on the stricture location, length, and number and options range from balloon dilatation to endoscopic urethrotomy to anastomotic and substitution urethrotomy. Postprocedural management includes urethrography to identify potential complications including urethral leak, graft failure, and stricture recurrence.

The value of magnetic resonance imaging geometric parameters in pre-assessing the surgical approaches of pelvic fracture urethral injury

Background

To investigate the correlation between the magnetic resonance urethrography and the surgical approach and complexity for the patients with pelvic fracture urethral injury (PFUI) by combining the geometry with magnetic resonance imaging (MRI).

Methods

Forty-three male patients with PFUI (part of the patients complicated with rectal injury) from January 2016 to December 2018 were analyzed in this retrospective research. All the patients underwent a delayed anastomotic urethroplasty and were divided into 2 groups according to the approaches (simple perineal approach or inferior pubectomy). For magnetic resonance urethrography, we measured and calculated the geometric parameters such as the gap distance between two urethral ends, the pubourethral vertical distance (PUVD), and the rectourethral median distance (RUMD).

Results

Of the 43 patients, 16 underwent inferior pubectomy and 27 underwent simple perineal approach. The numbers of patients with and without rectal injury history were 17 and 26, respectively. The operation time and intraoperative blood loss was significantly higher in the inferior pubectomy group. Multivariate logistic analysis revealed that gap distance and PUVD were independent factors of the surgical approaches. The accuracies were 83.7% and 67.4% respectively in the ROC curve analysis. In addition, the RUMD was significantly shorter in the patients with rectal injury history (1.4, 1.8 cm).

Conclusions

Longer gap distance and shorter PUVD were the two independent factors of the inferior pubectomy approach. Furthermore, among the patients with rectal injury history, the tissue posterior to the urethra was often weaker and should be carefully handled during the surgery.

Trial registration

This research has been registered on the Chinese Clinical Trial Registry. The registration number is ChiCTR2000030573.