Introduction: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for staghorn and large renal stones. The success of PCNL is highly related to optimal renal access. Upper calyceal puncture being more difficult and more demanding have relatively few studies presented. Aims and Objectives: This prospective study was carried out to evaluate the effectiveness and safety of upper calyceal versus lower calyceal puncture for the removal of complex renal stones through PCNL. Materials and Methods: A total of 94 patients underwent PCNL for complex renal stone in our institute. Fifty-one of them underwent lower calyceal, while 43 underwent upper calyceal puncture. The two approaches are compared as per total duration of surgery, intraoperative blood loss, infundibular/pelvic tear, rate of complete clearance and rate of postoperative complications (pulmonary, bleeding, fever and sepsis, etc.). Observation and Results: In our study, the success rate was 76.47% for those in the lower, 90.70% for those in the upper calyceal access group. Thoracic complications (hydrothorax) occurred to 1 patient in upper calyceal supracostal access group. Bleeding requiring blood transfusion happened to 5 patients in lower calyceal access and 1 in upper calyceal group. Conclusion: In our study for the management of complex renal calculi, we conclude that in a previously unoperated kidney, upper calyceal puncture through subcostal or supra 12th rib is a feasible option minimizing lung/pleural rupture and gives a better clearance rate. We suggest that with due precautions, there should not be any hesitation for upper calyceal puncture in indicated patients.
Abstract Background Atherosclerosis is a condition in which an adhesive substance called plaque accumulates over time inside the arteries. Plaque buildup results in the constriction of arteries, causing a shortage of blood supply to tissues and organs. Removing atherosclerotic plaques controls the development of acute ischemic stroke and heart diseases. It remains imperative for positive patient outcomes. Purpose This study sought to develop a minimally invasive technique for removing arterial plaques by applying focused ultrasound (FUS) energy on the metal surface of a nitinol catheter wire to induce inertial cavitation. The induced cavitation can deplete plaque mechanically inside the arteries, leading towards improved recanalization of blood vessels. Methods The enhanced cavitation effect induced by combining FUS with a metal catheter was first verified by exposing agar phantom gels with or without a 0.9‐mm diameter nitinol wire to an acoustic field produced by a 0.5‐MHz FUS transducer. The phenomenon was further confirmed in pork belly fat samples with or without a 3‐mm diameter nitinol catheter wire. Cavitation was monitored by detecting the peaks of emitted ultrasound signals from the samples using a passive cavitation detector (PCD). Cavitation threshold values were determined by observing the jump in the peak amplitude of signals received by the PCD when the applied FUS peak negative pressure (PNP) increased. To simulate arterial plaque removal, FUS with or without a catheter was used to remove tissues from pork belly fat samples and the lipid cores of human atherosclerotic plaque samples using 2500‐cycle FUS bursts at 10% duty cycle and a burst repetition rate of 20 Hz. Treatment outcomes were quantified by subtracting the weight of samples before treatment from the weight of samples after treatment. All measurements were repeated 5 times ( n = 5) unless otherwise indicated, and paired t ‐tests were used to compare the means of two groups. A p ‐value of <0.05 will be considered significant. Results Our results showed that with a nitinol wire, the cavitation threshold in agar phantoms was reduced to 2.6 MPa from 4.3 MPa PNP when there was no nitinol wire in the focal region of FUS. For pork belly fat samples, cavitation threshold values were 1.0 and 2.0 MPa PNP, with and without a catheter wire, respectively. Pork belly fat tissues and lipid cores of atherosclerotic plaques were depleted at the interface between a catheter and the samples at 2 and 4 MPa FUS PNP, respectively. The results showed that with a catheter wire in the focal region of a 3‐min FUS treatment session, 24.7 and 25.6 mg of lipid tissues were removed from pork belly fat and human atherosclerotic samples, respectively. In contrast, the FUS‐only group showed no reduction in sample weight. The differences between FUS‐only and FUS‐plus‐catheter groups were statistically significant ( p < 0.001 for the treatment on pork belly samples, and p < 0.01 for the treatment on human atherosclerotic samples). Conclusion This study demonstrated the feasibility of catheter‐assisted FUS therapy for removing atherosclerotic plaques.
Maintaining ureteral patency is imperative to preventing renal injury and systemic infection. Ureteral stents are small conduits connecting the kidney and the bladder. They have been widely used to treat ureteral obstructions and ureteral leaks. The most problematic and frequent stent-associated complication is stent encrustation. This occurs when mineral crystals (e.g. calcium, oxalate, phosphorus, struvite) are deposited onto the surface and internal lumen of the stent. Encrustation can lead to the obstruction of a stent and increases risk of systemic infection. As a result, ureteral stents need to be replaced typically every 2-3 months.In this study, we present a non-invasive, high-intensity focused ultrasound (HIFU)-based technique to recanalize obstructed stents. By taking advantage of the mechanical force produced by a HIFU beam, including acoustic radiation force, acoustic streaming, and cavitation, HIFU can break up encrustations, clearing the stent of obstruction.The ureteral stents for this study were obtained from patients undergoing ureteral stent removal. Under the guidance of ultrasound imaging, the encrustation in the stents were located, and then targeted by HIFU at frequencies of 0.25 and 1 MHz. The duty cycle of HIFU was 10%, and the HIFU burst repetition rate was 1 Hz, while the HIFU amplitude was varied to find the threshold pressure that would displace encrustations. The treatment duration was limited at 2 min (or 120 shots from HIFU). The treatments were carried out in two different orientations (parallel and perpendicular) of the ureteral stent with respect to the HIFU beam. For each setting, five treatments were conducted for a maximum duration of 2 min. During the entire treatment, an ultrasound imaging system was used to monitor the movement of encrustations inside the stent. The peak negative HIFU pressures needed to move the encrustations inside the stent was recorded for quantitative analysis.Our results demonstrated that at both 0.25 and 1 MHz ultrasound frequencies, obstructed stents could be recanalized. At 0.25 MHz, the needed average peak negative pressure was 0.52 MPa in parallel orientation and 0.42 MPa in perpendicular orientation. At 1 MHz, the needed average peak negative pressure was 1.10 MPa in parallel orientation and 1.15 MPa in perpendicular orientation CONCLUSIONS: This first in-vitro study has demonstrated the feasibility of non-invasive HIFU to recanalize ureteral stents. This technology has a potential to reduce the need for ureteral stent exchange.
. Atherosclerosis is the buildup of fats, cholesterol, and other substances on the inner walls of arteries. It can affect arteries of heart, brain, arms, legs, pelvis and kidney, resulting in ischemic heart disease, carotid artery disease, peripheral artery disease and chronic kidney disease. Laser-based treatment techniques like laser atherectomy can be used to treat many common atherosclerostic diseases. However, the use of laser-based treatment remains limited due to the high risk of complications and low efficiency in removing atherosclerostic plaques as compared with other treatment methods. In this study, we developed a technology that used high intensity focused ultrasound to assist laser treatment in the removal of the lipid core of atherosclerotic plaques.
Introduction: Hypospadias is a complex congenital deformity which requires meticulous surgical technique. Several techniques have been advocated during the past 150 years to address chordee and construction of neourethra. This study highlights the surgical techniques and experience with primary hypospadias cases. Materials and Methods: A total of 65 patients aged ranges from 1 to 18 years underwent primary hypospadias repair at our center from August 2007 to December 2012. Exclusion criteria - previous surgical attempt or with incomplete follow-up. Patients with inadequate phallic size and age <12 years were administered injection testosterone (Testoviron) prior to the surgery. Patients with significant chordee underwent chordee correction followed by urethral reconstruction by either tubularized incised plate (TIP) or on-lay flap repair/dartos flap repair. In all the patients, infant feeding tube was kept per urethrally for 3 weeks and was removed between the post-operative day 18 th and 21 st day. Results: Out of 65 patients, 24 patients underwent TIP. A total of 41 patients underwent on-lay flap repair; of this six patients of midscrotal/perineal hypospadias underwent a combination of paraurethral skin and on-lay flap repair. Chordee correction was done in all the five cases of chordee without hypospadias (congenital short urethra) and dysplastic, transparent urethra repaired with on-lay flap repair. In our study, complications like flap necrosis and fistula were seen in 10 cases and other minor complications like superficial epidermal sloughing were seen in 13 cases which healed with epithelialization. Meatal stenosis was more commonly observed with TIP (four cases) and in two cases of on-lay repair. Conclusion: Historically, hypospadias surgery was regarded as non-rewarding surgical reconstruction due to higher complication and failure rates. For hypospadias, if planned properly, primary single stage repair; acceptable surgical success is an achievable target.
Blood clot formation in vein, known as venous thromboembolism is a major disease worldwide. Ultrasound and laser-based treatment techniques have been developed to remove blood clots and recanalize occluded vessels. The applications of both technologies are hindered by their individual limitations. We tested a novel hybrid technology based on the spatio-temporally synchronized pulsed laser and ultrasound, namely, ultrasound-assisted endovascular laser thrombolysis (USELT) in an in-vitro- blood clot model and invivo rabbit model. The in vitro- study demonstrated enhanced thrombolysis with USELT as compared with ultrasound-only and laser-only. In in vivo study, out of seven treated rabbits in USELT group, the vein was fully or partially recanalized in five rabbits and poorly recanalized in two rabbits, whereas the vein treated with ultrasound-only and laser-only did not result in recanalization in any case. The in vitro- and in vivo study successfully demonstrated the feasibility of USELT for thrombolysis, and USELT has the potential to combine the advantages of both ultrasound and laser thrombolysis techniques and overcome their limitations.
Otalgia is one of the commonest symptoms for which patients report to the ear, nose and throat (ENT) outpatient department (OPD) and to the emergency department. Otalgia is a cardinal symptom of ear disease and its origin is varied, depending on its aetiology. While it is otogenic in most cases, it can be referred from a distant site which occurs as a result of a plethora of neural innervations that the ear receives. As the symptom has multiple aspects, a patient presenting with otalgia often poses a diagnostic challenge to a clinician and an otolaryngologist should be prepared to tackle these challenges to provide the best possible care to the patients.
Photo-mediated ultrasound therapy (PUT) is a novel therapeutic technique based on the combination of ultrasound and laser. The underlying mechanism of PUT is the enhanced cavitation effect inside blood vessels. The enhanced cavitation activity can result in bio-effects such as reduced perfusion in microvessels. The reduced perfusion effect in microvessels in the eye has the potential to control the progression of eye diseases such as diabetic retinopathy and age-related macular degeneration. Several in vivo studies have demonstrated the feasibility of PUT in removing microvasculature in the eye using rabbit eye model and vasculature in the skin using rabbit ear model. Numerical studies using a bubble dynamics model found that cavitation is enhanced during PUT due to the dramatic increase in size of air/vapor nuclei in blood. In addition, the study conducted to model cavitation dynamics inside a blood vessel during PUT found stresses induced on the vessel wall during PUT are higher than that at normal physiological levels, which may be responsible for bio-effects. The concentration of vasodilators such as nitric oxide and prostacyclin were also found to be affected during PUT in an in vitro study, which may limit blood perfusion in vessels. The main advantage of PUT over conventional techniques is non-invasive, precise, and selective removal of microvessels with high efficiency at relatively low energy levels of ultrasound and laser, without affecting the nearby structures. However, the main limitation of vessel rupture/hemorrhage needs to be overcome through the development of real-time monitoring of treatment effects during PUT. In addition to the application in removing microvessels, PUT-based techniques were also explored in treating other diseases. Studies have found a combination of ultrasound and laser to be effective in removing blood clots inside veins, which has the potential to treat deep-vein thrombosis. The disruption of atherosclerotic plaque using combined ultrasound and laser was also tested, and the feasibility was demonstrated.
'%3e%3ccircle r='20' fill='%23008'/%3e%3ccircle r='17.5' fill='%23fff'/%3e%3ccircle r='3.5' fill='%23008'/%3e%3cg id='d'%3e%3cg id='c'%3e%3cg id='b'%3e%3cg id='a' fill='%23008'%3e%3ccircle r='.875' transform='rotate(7.5 -8.75 133.5)'/%3e%3cpath d='M0 17.5.6 7 0 2l-.6 5L0 17.5z'/%3e%3c/g%3e%3cuse xlink:href='%23a' transform='rotate(15)'/%3e%3c/g%3e%3cuse xlink:href='%23b' transform='rotate(30)'/%3e%3c/g%3e%3cuse xlink:href='%23c' transform='rotate(60)'/%3e%3c/g%3e%3cuse xlink:href='%23d' transform='rotate(120)'/%3e%3cuse xlink:href='%23d' transform='rotate(-120)'/%3e%3c/g%3e%3c/svg%3e)
