[Show abstract][Hide abstract] ABSTRACT: To examine the feasibility of image-guided navigation using transrectal ultrasound (TRUS) to visualize the neurovascular bundle (NVB) during robot-assisted laparoscopic radical prostatectomy (RALP). The preservation of the NVB during radical prostatectomy improves the postoperative recovery of sexual potency. The accompanying blood vessels in the NVB can serve as a macroscopic landmark to localize the microscopic cavernous nerves in the NVB.
A novel, robotic transrectal ultrasound probe manipulator (TRUS Robot) and three-dimensional (3-D) reconstruction software were developed and used concurrently with the daVinci surgical robot (Intuitive Surgical, Inc., Sunnyvale, CA) in a tandem-robot assisted laparoscopic radical prostatectomy (T-RALP).
After appropriate approval and informed consent were obtained, 3 subjects underwent T-RALP without associated complications. The TRUS Robot allowed a steady handling and remote manipulation of the TRUS probe during T-RALP. It also tracked the TRUS probe position accurately and allowed 3-D image reconstruction of the prostate and surrounding structures. Image navigation was performed by observing the tips of the daVinci surgical instruments in the live TRUS image. Blood vessels in the NVB were visualized using Doppler ultrasound.
Intraoperative 3-D image-guided navigation in T-RALP is feasible. The use of TRUS during radical prostatectomy can potentially improve the visualization and preservation of the NVB. Further studies are needed to assess the clinical benefit of T-RALP.
[Show abstract][Hide abstract] ABSTRACT: Precise targeting is essential for adequate treatment of lesions during image-guided therapy. The aim of this study was to compare the performance of two emerging image-guided targeting technologies in a phantom model.
A computer-assisted navigation system and AcuBot were tested using three operators: an interventional radiologist and two endourologists. Fiducials were placed in an anatomic gelatin phantom and targeted by both systems. The images were reconstructed and analyzed using a specialized software package (Amira; Visage Imaging, Carlsbad, CA). Accuracy was assessed by measuring proximity of the tip of the needle to the fiducial on computed-tomography-guided imaging. Accuracy and time to target were quantified and compared.
The mean distance from the desired target for AcuBot was 1.2 mm (range: 0.39-2.82). The mean distance from the desired target for the navigation system was 5.8 mm (range: 1.8-11.9). The AcuBot was significantly more accurate than the navigation system (p < 0.0001). The mean time from target acquisition to needle placement was 37 seconds (range: 15-75) for the AcuBot and 108 seconds (range: 45-315) for the navigation system (p = 0.001).
Emerging technologies hold promise for increased accuracy during percutaneous targeted procedures. Both the AcuBot and the computer-assisted navigation system were accurate and efficient in a phantom targeting model. AcuBot was significantly more accurate, faster, and less user dependent than the navigation system. Further studies in animal and clinical studies are warranted to further advance this promising technology.
Full-text · Article · Aug 2010 · Journal of endourology / Endourological Society
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to examine the triage role of scrotal Doppler ultrasonography (DUS) as the primary preoperative diagnostic tool in patients presenting to the emergency department (ED) with acute scrotum.
Patients who presented to the ED with acute scrotum and underwent scrotal DUS in the ultrasound unit over a 3-year period (2004-2007) were included in the study. Patient characteristics, DUS findings, and clinical management were retrospectively collected and reviewed. Doppler ultrasonographic diagnoses were compared with histopathologic findings for patients who underwent exploration and with final diagnoses at the time of discharge for patients undergoing medical treatment.
A total of 620 consecutive patients with 669 DUS examinations were included. The most common scrotal DUS diagnoses were epididymitis, hydrocele, varicocele, and orchitis. Scrotal trauma was present in 77 cases. Hospitalization followed the initial ED evaluation for 155 patients; 68 underwent surgery. Testicular torsion was ultrasonographically suspected in 20 patients and confirmed in 18. Scrotal malignancy was incidentally diagnosed in 13 patients and testicular hematoma in 8. Doppler ultrasonography for the diagnosis of testicular torsion had 94% sensitivity, 96% specificity, 95.5% accuracy, an 89.4% positive predictive value (PPV), and a 98% negative predictive value (NPV). Doppler ultrasonography for the diagnosis of testicular malignancy had 92% sensitivity, 95% specificity, 94% accuracy, a 78.5% PPV, and a 98% NPV.
Scrotal DUS is a highly sensitive preoperative diagnostic tool, thereby validating its routine use in the initial triage of patients with acute scrotum presenting to the ED.
Full-text · Article · Jan 2010 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
Acute scrotum is not a rare complaint in the ED. The diagnosis is difficult due to the diversity of etiologies with this clinical presentation. Doppler ultrasonography study (DUS) is considered the mainstay diagnostic imaging modality for the assessment of acute scrotum. Our purpose was to assess the role of scrotal DUS in the evaluation of patients presenting to the ED with acute scrotum by correlating DUS diagnoses to surgical findings and clinical management.
METHOD AND MATERIALS
The study included patients who presented at the ED with an acute scrotum, and underwent scrotal DUS in the US unit from Oct. 2004 to Oct. 2007. Patient characteristics, DUS findings and clinical management were reviewed. For those patients who underwent surgery, DUS diagnoses were compared to the macroscopic histopathology findings and final diagnoses at time of discharge from hospitalization. The sensitivity, specificity, accuracy, PPV and NPV of DUS diagnosis were calculated.
661 DUS examinations were performed in 612 patients (age 2 mth to 95 yrs). Clinical findings included scrotal pain in 591 (89%) cases, erythema in 70 (11%) and swelling in 264 (40%). Scrotal trauma was reported in 71 cases. Common scrotal DUS diagnoses were epididymitis in 227 (34%) cases, hydrocele in 210 (32%), varicocele in 110 (17%) and orchitis in 93 (14%). In 133 (20%) cases hospitalization followed the initial ER evaluation and in 51 (38%) cases surgery was the initial therapeutic approach. In 16 patients of the latter subgroup, testicular torsion was the final diagnosis at time of discharge. In 13 subjects malignancy was diagnosed; seminoma in 3, mixed germ cell tumor in 4, embryonal cell tumor in 2, secondary spread in 3 and 1 necrotic sample. The calculated sensitivity, specificity and accuracy of scrotal DUS for the diagnosis of testicular torsion were 94%, PPV of 88% and NPV of 97%. Sensitivity of 85%, specificity of 92%, 90% accuracy, 78% PPV and 95% NPV were calculated for testicular tumor.
The high negative predictive value of DUS for the diagnosis of acute scrotum validates the use of this modality as the first diagnostic approach for the triage of patients presenting to the ER with acute scrotum.
Scrotal DUS is the basis of therapeutic approach for acute scrotum, enabling early recognition of scrotal emergency requiring surgical intervention, as opposed to other entities treated conservatively