Robotic Partial Nephrectomy for a Peripheral Renal Tumor

Partial nephrectomy (PN) is the preferred surgical treatment for T1 renal tumors whenever technically feasible. When properly performed, it allows preservation of nephron mass without compromising oncologic outcomes. This reduces the postoperative risk of renal insufficiency, which translates into better overall survival for the patients. PN can be technically challenging, because it requires the surgeon to complete the tasks of tumor excision, hemostasis and renorrhaphy, all within an ischemic time of preferably below 30 minutes. The surgeon needs to avoid violating the tumor margins while leaving behind the maximal parenchymal volume at the same time. Variations such as zero ischemia, early unclamping, and selective clamping have been developed in an attempt to reduce the negative impact of renal ischemia, but inevitably add to the steep learning curves for any surgeon. Being able to appreciate the fine details of each surgical step in PN is the fundamental basis to the success of this surgery. The use of the robotic assistance allows a good combination of the minimally invasive nature of laparoscopic surgery and the surgical exposure and dexterity of open surgery. It also allows the use of adjuncts such as concurrent ultrasound assessment of the renal mass and intraoperative fluorescence to aid the identification of tumor margins, all with a simple hand switch at the console. Robot-assisted laparoscopic PN is now the most commonly performed type of PN in the United States and is gaining acceptance on the global scale. In this video, we illustrate the steps of robot-assisted laparoscopic PN and highlight the technical key points for success

Impact of positive surgical margins on overall survival after partial nephrectomy—A matched comparison based on the National Cancer Database

Introduction The impact of positive surgical margins (PSM) in partial nephrectomy (PN) has been a controversy. Previous studies on the relationship between PSM and overall survival (OS) were either underpowered or had highly dissimilar groups. We used the National Cancer Database with propensity score matching to determine the association between PSM and OS after PN. Materials and methods We identified patients with T1/T2 N0M0 renal cancer treated with PN between 2004 and 2009, and divided them into 2 groups based on their margin status. We used propensity score matching to ensure similarities in age, comorbidity score (CCI), tumor size, histology, and grade between groups. Covariates were compared by χ2 test. Cox multiple regression was used to estimate the hazard ratios (HR) for all-cause mortality. OS between matched groups were compared by log-rank, Breslow and Tarone-Ware tests. Results After excluding those with missing data on margin or survival status, 20,762 patients were eligible for matching. Each matched group had 1,265 patients, similar in age, sex, race, CCI, tumor size, histology, and grade. There were 386 recorded all-cause mortalities over a median follow-up duration of 72.6 months. Cox multiple regression showed a higher risk of all-cause mortality among cases with PSM (HR: 1.393, P = 0.001). Old age, high CCI, and large tumors had higher risks, while papillary and chromophore histologic subtypes had lower risks. PSM was associated with significantly worse OS by log-rank, Breslow, and Tarone-Ware tests. Conclusion PSM is associated with significantly worse OS after PN

Novel Use of Folate-Targeted Intraoperative Fluorescence, OTL38, in Robot-Assisted Laparoscopic Partial Nephrectomy: Report of the First Three Cases

Partial nephrectomy is now the preferred surgical option for small renal tumors because it allows nephron preservation without compromising oncologic clearance. Its outcomes depend on the surgeon's ability to continuously identify the edges of the tumor during resection, thus leaving an adequate margin around the tumor without excessive removal of normal parenchyma, as well as keeping a short ischemic time. Folate receptors are highly abundant in the normal kidney, and there is a difference in folate receptor expression between malignant and normal renal tissues. Thus, the use of fluorescent agents that target folate receptors should result in differential fluorescence between the tumor and surrounding parenchyma during partial nephrectomy, which, in turn, helps tumor demarcation for identification and resection. A phase 2 study on the novel use of OTL38 in robot-assisted laparoscopic partial nephrectomy is currently in progress in our institution. The outcomes of the first three cases have shown the possible advantages of OTL38 in intraoperative tumor identification before resection and recognition of residual disease in the surrounding parenchyma after resection. The tumors typically appeared dark while the surrounding parenchyma showed brighter fluorescence. Immediately after tumor resection, the margins of all the specimens appeared to have a uniformly bright fluorescence, suggestive of an intact margin of normal renal parenchyma along the plane of excision. The pattern of intraoperative fluorescence correlates well with immunohistochemistry. No OTL38-related adverse effects have been seen among these three patients. We present the outcomes of these three cases, illustrated with intraoperative and immunohistochemistry images

Medical therapy for clinical benign prostatic hyperplasia: α1 Antagonists, 5α reductase inhibitors and their combination

Medical therapy for clinical benign prostatic hyperplasia (BPH) has advanced significantly in the last 2 decades. Many new α1 antagonists and 5α reductase inhibitors (5ARi) are now commercially available. The practicing urologist must decide on the most appropriate medication for his patients, taking into consideration various factors like efficacy, dosing regime, adverse effects, cost, patient's socioeconomic background, expectations, drug availability and his own clinical experience. The use of combination therapy added further to the complexity in clinical judgment when prescribing. We highlight some of the key points in prescribing α1 antagonists, 5ARi and their combination, based on our viewpoints and experience as urologists in an Asian clinical setting. Keywords: 5α Reductase inhibitors, Adrenergic α1 receptor antagonists, Drug therapy, Combination, Prostatic hyperplasi

On-table Diagnostic Accuracy and the Clinical Significance of Routine Exploration in Open Appendectomies

The current practice of further exploration for other intra-abdominal pathology only when a normal appendix is found may leave other organic causes of acute abdomen undetected if the surgeon's on-table diagnostic accuracy is low. Methods: In this retrospective study in 518 patients who underwent surgery for acute appendicitis, the on-table operative diagnosis of surgeons was correlated with the histological diagnosis of pathologists. Results: Surgeons were unable to make an accurate on-table diagnosis in 14.3% of cases. The sensitivity for diagnosing normal appendices was also low at 51.3%, suggesting that almost half of normal appendices were misdiagnosed as acute appendicitis and there was no further exploration for other pathology. It was also found that surgeon's experience, patient gender and patient age had no significant effect on diagnostic accuracy. Conclusion: Based on these results, it seems that the on-table diagnostic accuracy in open appendectomies is low and surgeons' on-table diagnosis should not be the determining factor for whether further exploration is necessary. Exploration for other intra-abdominal pathology should be routine irrespective of the on-table diagnosis, the surgeon's experience and patient gender and age. An alternative is minimal-access surgery in which inspection of other intra-abdominal organs can be performed more easily

OTL-38-Guided Fluorescent Imaging in Renal Cell Cancer Robotic Partial Nephrectomy

Introduction and Objective: The folate receptor (FR) protein is upregulated in numerous epithelial malignancies while having limited expression on normal tissues. This overexpression of FR in renal-cell carcinoma (RCC) can be exploited by attaching nearly any therapeutic or imaging agent for delivery to cancer cells. In one of its first applications, platinum-resistant ovarian cancer, folate was used to deliver pegylated liposomal doxorubicin (a folate-linked vinca alkaloid) and improved progression-free survival versus standard treatment. RCCs are thought to be the second highest FR-expressing cancer. OTL-38 is a folate analogue conjugated with a fluorescent dye that emits light in the near infrared spectrum. This longer wavelength allows for deeper penetration of the fluorescent light through tissues with the potential to better image tumors beneath adipose tissue or deeper into organ parenchyma. We are currently conducting a pilot, phase 2, nonrandomized study in patients with RCC, scheduled to undergo primary, partial, or radical nephrectomy. The aim is to explore the use of OTL-38 and fluorescence imaging to observe RCC at the margins of resection in partial nephrectomy and in lymph node(s) or other metastases for radical nephrectomy. Methods: Currently two patients have participated in the trial to date with an accrual target of 20 patients. The first was a 67-year-old male with an incidental 2.2 cm right-sided renal mass, and the second was a 70-year-old male with an enlarging 2 cm renal mass. Per protocol, both patients were administered OTL-38 in the preoperative area 1 hour before the procedure. Subsequently, both procedures were performed with robotic assistance as per normal routine with the use of Firefly fluorescence to aid in observation of OTL-38 uptake. Results: Intraoperative guidance through OTL-38 demonstrated minimal to no uptake of the OTL-38 as seen by Firefly fluorescence (green color). Surprisingly, the normal renal parenchyma showed strong uptake of OTL-38 as seen by Firefly fluorescence. Both pathology reports revealed conventional clear cell RCC. Immunohistochemistry slides of the tumor revealed only mild staining for folate. In contrast, immunohistochemistry slides of the normal renal parenchyma in the surgical margin revealed a strongly positive stain for folate. Conclusions: In conclusion, our first two patients' renal tumors did not stain strongly for folate; however, the normal renal parenchyma did, which served as an intraoperative guide to confirm a negative margin. Further study of patients will reveal whether folate receptors are, in fact, predominant or not in renal cell cancer

Cell-Based Functional IgE Assays Are Superior to Conventional Allergy Tests for Shrimp Allergy Diagnosis.

BackgroundThe diagnosis of shellfish allergy currently relies on patient history, skin prick test (SPT), and serum specific IgE (sIgE) quantification. These methods lack sufficient diagnostic accuracy, whereas the gold standard of oral food challenges is risky and burdensome. Markers of reactivity and severity of allergic reactions to shellfish will improve clinical care of these patients.ObjectivesThis study compared the diagnostic performance of SPT, sIgE, basophil activation test (BAT), and IgE crosslinking-induced luciferase expression (EXiLE) test for shrimp allergy.MethodsThirty-five subjects with documented history of shrimp allergic reactions were recruited and grouped according to results of double-blind, placebo-controlled food challenge (DBPCFC). In addition to routine diagnostics, BAT (Flow CAST) and EXiLE test with shrimp extract and tropomyosin were performed.ResultsOf 35 subjects, 15 were shrimp allergic with pruritus, urticaria, and itchy mouth on DBPCFC, whereas 20 were tolerant to shrimp. Tropomyosin only accounted for 53.3% of sensitization among subjects with challenge-proven shrimp allergy. BAT using shrimp extract as stimulant showed the highest area under curve value (0.88), Youden Index (0.81), likelihood ratio (14.73), odds ratio (104), and variable importance (4.27) when compared with other assays and tropomyosin diagnosis. Results of BAT significantly correlated with those of EXiLE (r = 0.664, P < .0001).ConclusionsBAT is a more accurate diagnostic marker for shrimp allergy than SPT and shrimp sIgE, whereas the EXiLE test based on an IgE crosslinking assay is a good alternative to BAT. Tropomyosin may not be the most important shrimp allergen in Chinese, which warrants further investigation to search for other major allergens and diagnostic markers