The relationship between the force applied and perceived by the surgeon during ureteral access sheath placement: ex-vivo experimental model.

PURPOSE: To define a peak force of insertion (PFOI) threshold for ureteral damage during ureteral access sheath (UAS) placement on an experimental ureteral orifice model. METHODS: A specially designed water tank using 2 laparoscopic 5 mm ports and 2 different size (10 Fr and 8 Fr) sealing cap adaptors (SCA) as ureteral orifices was used to perform the test. A 10-12 Fr UAS was fixed to a load cell and the force of insertion (FOI) was continuously recorded with a digital force gauge.13 experts in the field of endourology who participated performed 3 UAS insertions. The FOI was recorded initially with 10 Fr followed by 8 Fr SCA. On the final insertion, the orifice was obstructed, leaving a 5 cm length to insert the UAS. The experts were asked to "Stop at the point they anticipate ureteral damage, and they would not proceed in real life". RESULTS: Using 10 Fr SCA the PFOI was 2.12 ± 0.58 Newton (N) (range:1.48-3.48) while 8 Fr SCA showed a PFOI 5.76 ± 0.96 N (range:4.05-7.35). Six of the experts, said they would stop proceeding when they reached above 5.1 N. Three experts had PFOI < 5.1 N and the other 4 stated they would go with PFOIs of 5.88, 6.16, 6.69 and 7.35 N when using SCA of 8 Fr.The highest load they would stop proceeding had a PFOI of 6.09 ± 1.87 N (range: 2.53-10.74). CONCLUSION: The PFOI threshold for ureteral damage inserting UAS of the experts is variable. Although FOI is a subjective perception, experience suggests that ureteral injury may occur at an average of 6.05 N perceived by surgeons' tactile feedback. In-vivo measurement of UAS PFOI may confirm a threshold.

High-frequency shock wave lithotripsy: stone comminution and evaluation of renal parenchyma injury in a porcine ex-vivo model.

BACKGROUND: The electrohydraulic high-frequency shock wave (Storz Medical, Taegerwilen, Switzerland) is a new way to create small fragments with frequencies up to 100 Hertz (Hz). This study evaluated the efficacy and safety of this method in a stone and porcine model. MATERIALS AND METHODS: BEGO stones were put in a condom in a specifically designed fixture treated with different modulations to see stone comminution. Standardized ex vivo porcine model with perfused kidneys with 26 upper and lower poles of 15 kidneys was treated with the following modulations: voltage 16-24 kV, capacitor 12 nF and frequency up to 100 Hz. 2000-20,000 shock waves were applied to each pole. The kidneys were perfused with barium sulfate solution (BaSO4) and x-ray was performed to quantify the lesions using pixel volumetry. RESULTS: There was no correlation between the number of shock waves and the powdering degree or the applied Energy and the grade of pulverization in the stone model. Regarding the perfused kidney model, the number of shock waves, applied voltage and frequency had no direct correlation with the occurrence of parenchymal lesions The detected lesions of the renal parenchyma were minimal, technical parameters had no significant impact and the lesions did not differ from the results of former experiments using 1-1.5 Hz in the same model. CONCLUSIONS: High-frequency shock wave lithotripsy can produce small stone fragments to pass in a very short time. The injury to the renal parenchyma is comparable to the results of the conventional SWL using 1-1.5 Hz.

Transperitoneal and retroperitoneal approach in laparoscopic partial nephrectomy for posterior cT1 renal tumors: A retrospective, two-centers, comparative study.

OBJECTIVES: To compare perioperative, oncological and functional outcomes of Laparoscopic Transperitoneal Partial Nephrectomy (LTPN) and Retroperitoneal Laparoscopic Partial Nephrectomy (LRPN) for posterior, cT1 renal masses (RMs). MATERIALS AND METHODS: Databases of two urologic institutions applying different laparoscopic surgical approaches on posterior cT1 RMs between June 2016 and November 2018 were retrospectively evaluated. Data on patient demographics, perioperative data and tumor histology were collected and further analyzed statistically. RESULTS: Each group consisted of 15 patients. Baseline characteristics were comparable in each group. When compared to LTPN, LRPN was associated with significantly shorter operative time (OT) (115 min versus 199 min, p < 0.05). No significant differences were detected in the other outcomes. CONCLUSIONS: LRPN is associated with a significantly shorter OT compared to LTPN for posterior cT1 RMs. Both surgical approaches are safe, feasible and credible, demonstrating optimal results.

Undiagnosed paraganglioma; A challenge during laparoscopic retroperitoneal resection.

OBJECTIVE: Report our experience of the management of a patient with undiagnosed retroperitoneal paraganglioma and the intraoperative complications that the theatre team faced. CASE REPORT: We present a case of a 36-year-old patient who during oncological follow-up for a previous diagnosis of parotid acinar cell carcinoma was incidentally identified as having an interaortocaval tumour. Following routine preoperative assessment the patient was arranged to undergo a laparoscopic retroperitoneal tumour resection. After minimal tumour manipulation the patient developed cardiac rhythm abnormalities and became hypertensive. The tumour was successfully removed laparoscopically after a cautious inter- aortocaval dissection. Abruptly, prior to extraction of the tumour containing endobag, the patient developed cardiac arrest. Following 35 minutes of life support measures there was a return of spontaneous circulation. The endobag was laparoscopically removed from the abdominal cavity 24 hours later using the initial operative port sites. The patient´s progression was satisfactory and he could be discharged six days postoperatively. CONCLUSIONS: Asymptomatic undiagnosed paragangliomas represent a real challenge during laparoscopic operations. Haemodynamic changes and life-threatening events can arise acutely intraoperatively, where an immediate and coordinated response of the whole theatre team may be required to avoid fatal outcome.

Long-term oncological outcomes after laparoscopic radical prostatectomy.

OBJECTIVES: To investigate long-term oncological outcomes after laparoscopic radical prostatectomy (LRP). To identify parameters influencing recurrence-free survival in a single-institution series. PATIENTS AND METHODS: All patients underwent LRP using the transperitoneal retrograde Heilbronn technique. High-risk patients received adjuvant treatment according to an institutional algorithm based on prostate-specific antigen (PSA), Gleason score, tumour-node-metastasis stage, margin status and tumour volume. Data were collected prospectively on operative and postoperative parameters beginning in 1999. Complete follow-up data of 370 of the first 500 consecutive patients are available. Biochemical recurrence was defined as two consecutive PSA levels <0.2 ng/mL within the follow-up period. Kaplan-Meier estimates and Cox regression were applied to examine recurrence-free survival times. RESULTS: The estimated biochemical recurrence-free survival (BCRFS) rates 10 years after LRP were 80.2% in patients staged pT2, 47.4% in those staged pT3a and 49.8% in those staged pT3b/4, confirming a better prognosis in patients with organ-confined disease (P < 0.001). In the multivariate Cox regression analysis, only Gleason score and pT stage significantly influenced BCRFS. The 10-year clinical progression-free survival rates were 97.2% (pT2), 84.4% (pT3a) and 78.1% (pT3b/4), and prostate cancer-specific survival estimates were 100% (pT2), 97.3% (pT3a) and 90.6% (pT3b/4). CONCLUSIONS: The 10-year biochemical and clinical progression-free survival after LRP combined with a risk-adapted concept of adjuvant therapy is high, while prostate-cancer specific mortality is low. Our data shows no negative impact of laparoscopic techniques on oncologic outcomes compared to large series after retropubic radical prostatectomy. In a multivariate Cox regression, only Gleason score and pT stage had significant impact on BCRFS.

Small-incision access retroperitoneoscopic technique (SMART) pyeloplasty in adult patients: comparison of cosmetic and post-operative pain outcomes in a matched-pair analysis with standard retroperitoneoscopy: preliminary report.

OBJECTIVES: To present small-incision access retroperitoneoscopic technique pyeloplasty (SMARTp), a novel mini-laparoscopic approach for management of uretero-pelvic junction obstruction (UPJO) in adults including comparison with the standard retroperitoneoscopic technique (SRTp). METHODS: In a non-randomised study, we matched 12 adult patients treated from August to November 2010 by SMARTp with 12 patients treated with SRTp from January to November 2010. Mini-laparoscopic retroperitoneal space was created with a home-made 6-mm balloon trocar. One 6-mm (for 5-mm 30° telescope) and two 3.5-mm trocars (for 3-mm working instrument) were used. SRTp was performed with 11- and 6-mm trocar. Primary endpoints included evaluation of cosmetic appearance and post-operative pain evaluated respectively by the patient and observer scar assessment scale (POSAS) and analogue visual scale (VAS). Secondary endpoints were comparison between operative and functional parameters. RESULTS: Cosmetic cumulative results were statistically significant in favour of SMARTp (POSAS: 37.9 vs. 52.4; P = 0.002). A better trend has been shown by post-operative pain (first to fourth day VAS), although not statistically significant (4.2 vs. 4.9, P = 0.891). No differences were recorded in terms of operative time, pre- and post-operative Hb difference, DJ-stent removal and resistive index (RI) improvement. The SMARTp group showed a faster drain removal (2.4 vs. 3.4 day, P = 0.004) and discharge (4.5 vs. 5.4 day P = 0.017). CONCLUSIONS: Preliminary data support SMARTp as safe procedures in experienced hands, providing better cosmetic results compared to SRTp. Further studies and clinical randomised trial performed in a larger population sample are requested.

Laparoscopic techniques for removal of renal and ureteral calculi.

BACKGROUND AND PURPOSE: Although most ureteral and renal stones are managed using endourologic techniques or shockwave lithotripsy in daily clinical practice, stone surgery has not completely disappeared. The increasing experience with laparoscopy in urology poses the question of whether urolithiasis may be an indication for laparoscopy. MATERIALS AND METHODS: A review of the literature was conducted to point out the indications and techniques of laparoscopic stone surgery. RESULTS: Indications for stone surgery are anatomic abnormalities, such as horseshoe kidneys, malrotated kidneys, or ectopic kidneys; symptomatic stones in diverticula of the renal pelvis; and extremely large stones, especially in children; or concomitant open or laparoscopic surgery. After failure of endourologic stone removal or shockwave lithotripsy, stone surgery may be a second option. In experienced hands, most procedures can be performed laparoscopically, either using a retroperitoneal or a transperitoneal approach. Accurate planning and imaging before surgery is mandatory. Intracorporeal ultrasonography or combined laparoscopic and endourologic techniques may be useful in difficult cases. Functional outcomes and complication rates of the laparoscopic approach are comparable to those of open surgery. The benefits of laparoscopy are lower postoperative morbidity, shorter hospitalization, shorter convalescence time, and better cosmetic results. CONCLUSIONS: Laparoscopic removal of renal and ureteral calculi plays a role in special cases of urolithiasis. In experienced hands, it can be performed safely and efficiently and may therefore replace open stone surgery in most indications.

Complications in percutaneous nephrolithotomy.

OBJECTIVE: This review focuses on a step-by-step approach to percutaneous nephrolithotomy (PNL) and its complications and management. METHODS: Based on institutional and personal experience with >1000 patients treated by PNL, we reviewed the literature (Pubmed search) focusing on technique, type, and incidence of complications of the procedure. RESULTS: Complications during or after PNL may be present with an overall complication rate of up to 83%, including extravasation (7.2%), transfusion (11.2-17.5%), and fever (21.0-32.1%), whereas major complications, such as septicaemia (0.3-4.7%) and colonic (0.2-0.8%) or pleural injury (0.0-3.1%) are rare. Comorbidity (i.e., renal insufficiency, diabetes, gross obesity, pulmonary disease) increases the risk of complications. Most complications (i.e., bleeding, extravasation, fever) can be managed conservatively or minimally invasively (i.e., pleural drain, superselective renal embolisation) if recognised early. CONCLUSIONS: The most important consideration for achieving consistently successful outcomes in PNL with minimal major complications is the correct selection of patients. A well-standardised technique and postoperative follow-up are mandatory for early detection of complications.