A study on the theoretical and practical accuracy of conoscopic holography-based surface measurements: toward image registration in minimally invasive surgery.

BACKGROUND: Registered medical images can assist with surgical navigation and enable image-guided therapy delivery. In soft tissues, surface-based registration is often used and can be facilitated by laser surface scanning. Tracked conoscopic holography (which provides distance measurements) has been recently proposed as a minimally invasive way to obtain surface scans. Moving this technique from concept to clinical use requires a rigorous accuracy evaluation, which is the purpose of our paper. METHODS: We adapt recent non-homogeneous and anisotropic point-based registration results to provide a theoretical framework for predicting the accuracy of tracked distance measurement systems. Experiments are conducted a complex objects of defined geometry, an anthropomorphic kidney phantom and a human cadaver kidney. RESULTS: Experiments agree with model predictions, producing point RMS errors consistently < 1 mm, surface-based registration with mean closest point error < 1 mm in the phantom and a RMS target registration error of 0.8 mm in the human cadaver kidney. CONCLUSIONS: Tracked conoscopic holography is clinically viable; it enables minimally invasive surface scan accuracy comparable to current clinical methods that require open surgery.

Splenosis as a cause of testicular pain: laparoscopic management.

This is a case report of a 37-year-old man with severe testicular pain unresolved after conventional investigative and therapeutic methods. On the basis of his history of abdominal trauma followed by emergency splenectomy and evidence of functioning splenic tissue on a radionuclide scan, the diagnosis of splenosis was established. Laparoscopic exploration was done, and the initial diagnosis confirmed. Splenic tissue located at the right inguinal ring was removed. Testicular pain abated after the procedure.

Complications of acucise endopyelotomy.

Endoscopic management of ureteropelvic junction (UPJ) obstruction has a success rate of 80% to 86%. We have been performing a ureteral cutting balloon procedure under fluoroscopic control (Acucise endopyelotomy) for UPJ obstruction at Loyola University Medical Center since 1991. The overall success rate in 77 patients was 78%. All patients had a preoperative intravenous urogram or a retrograde pyelogram, but none had vascular imaging studies. Acucise endopyelotomy consisted of a posterolateral incision of the UPJ and placement of an endopyelotomy or double-J stent. Foley catheter placement at the end of the procedure demonstrated significant gross hematuria in three patients (4%). All three remained hemodynamically stable but with significant drops in postprocedure hemoglobin levels, which necessitated blood transfusion. Aggressive management included angiographic studies and embolization of lower-pole branching arteries in two patients (3%). One patient stopped bleeding after being given two units of blood. None of the patients required an open exploratory procedure. Although the risk of vascular injury is low with Acucise endopyelotomy, prolonged postoperative gross hematuria does mandate investigation and observation. Angiographic embolization appears to be the therapeutic modality of choice for patients with hemorrhagic complications after an Acucise endopyelotomy.

The laparoscopic cooling sheath: novel device for hypothermic preservation of kidney during temporary renal artery occlusion.

Hypothermia is commonly used to prevent ischemic renal damage during complex nephron-sparing surgical procedures requiring temporary renal artery occlusion. We developed a novel Cooling Sheath device, which is compatible with laparoscopy, to protect the kidney hypothermically during 60 minutes of temporary arterial occlusion in a laparoscopic swine model. Comparison of temperature curves and histology to control groups undergoing open slush surface cooling and laparoscopic warm ischemia for similar time periods was performed. Optimal hypothermic temperatures were reached rapidly and maintained with the use of the Cooling Sheath. Ischemic damage, present in all kidneys subjected to warm ischemia, was not found on histopathologic examination of the cooled kidneys. This new device provides hypothermic protection of the kidney during ischemia. The use of the Cooling Sheath combined with temporary arterial occlusion will allow more complex nephron-sparing renal surgery to be performed using laparoscopy.

Staging pelvic lymphadenectomy for localized carcinoma of the prostate: a comparison of 3 surgical techniques.

PURPOSE: Pelvic lymph node dissection continues to be the most effective method of staging extracapsular adenocarcinoma of the prostate. Three principal methods of pelvic lymph node dissection are currently available: intraperitoneal laparoscopic, minilaparotomy and the standard open modified pelvic lymph node dissection. In the hope of determining some of the relative advantages and disadvantages associated with each technique a comparison of these approaches was made. MATERIALS AND METHODS: Of 68 patients with histologically proved clinical stage T3N0M0 adenocarcinoma of the prostate who underwent staging pelvic lymph node dissection 38 underwent modified open, 19 laparoscopic and 11 minilaparotomy procedures. The efficacy of node sampling, resource expenditure and complication rates were compared among the 3 groups. RESULTS: No statistically significant difference was observed in terms of the number of nodes harvested with each technique. Resource expenditure analysis revealed significantly increased operative and procedural time requirements for laparoscopic pelvic lymph node dissection compared to modified open and minilaparotomy procedures. Total hospital stay was significantly longer for the modified open pelvic lymph node dissection (mean plus or minus standard deviation 6.5 +/- 0.9 days) compared to the laparoscopic (mean 2.7 +/- 1.1 days) and minilaparotomy (mean 3.3 +/- 0.2 days) groups. Multiple complications, such as ileus, lymphocele and urinary retention, were observed in the modified open pelvic lymph node dissection group. No complications were noted in the other 2 groups. CONCLUSIONS: Comparison of laparoscopic and minilaparotomy procedures to modified open pelvic lymph node dissection revealed similar staging efficacy, and decreased total hospital stay and complications. Laparoscopic pelvic lymph node dissection required increased operative time. Minilaparotomy should become the open surgical procedure of choice for pelvic lymph node dissection, particularly at institutions where the laparoscopy learning curve, equipment expense and time disadvantages cannot be overcome.