Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Rita Quesada is active.

Publication


Featured researches published by Rita Quesada.


Scientific Reports | 2016

Irreversible electroporation of the liver: is there a safe limit to the ablation volume?

Patricia Sánchez-Velázquez; Alberto Villanueva; Rita Quesada; Clara Pañella; Marta Cáceres; Dimitri Dorcaratto; Anna Andaluz; Xavier Moll; Macarena Trujillo; Jose M. Burdio; Enrique Berjano; Luis Grande; Antoni Ivorra; Fernando Burdío

Irreversible electroporation is a fast-growing liver ablation technique. Although safety has been well documented in small ablations, our aim is to assess its safety and feasibility when a large portion of liver is ablated. Eighty-seven mice were subjected to high voltage pulses directly delivered across parallel plate electrodes comprising around 40% of mouse liver. One group consisted in 55 athymic-nude, in which a tumor from the KM12C cell line was grown and the other thirty-two C57-Bl6 non-tumoral mice. Both groups were subsequently divided into subsets according to the delivered field strength (1000 V/cm, 2000 V/cm) and whether or not they received anti-hyperkalemia therapy. Early mortality (less than 24 hours post-IRE) in the 2000 V/cm group was observed and revealed considerably higher mean potassium levels. In contrast, the animals subjected to a 2000 V/cm field treated with the anti-hyperkalemia therapy had higher survival rates (OR = 0.1, 95%CI = 0.02–0.32, p < 0.001). Early mortality also depended on the electric field magnitude of the IRE protocol, as mice given 1000 V/cm survived longer than those given 2000 V/cm (OR = 4.7, 95%CI = 1.8–11.8, p = 0.001). Our findings suggest that ionic disturbances, mainly due to potassium alterations, should be warned and envisioned when large volume ablations are performed by IRE.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2012

Laparoscopic Distal Pancreatectomy: Feasibility Study of Radiofrequency-Assisted Transection in a Porcine Model

Dimitri Dorcaratto; Fernando Burdío; Dolors Fondevila; Anna Andaluz; Ignasi Poves; María de los Ángeles Martínez; Rita Quesada; Enrique Berjano; Luis Grande

BACKGROUND AND AIM Despite technological improvements in pancreatic surgery, the incidence and morbidity of pancreatic leak after resection of distal pancreas are persistently high in most series. Laparoscopic distal pancreatectomy (LDP) is today the gold standard procedure for benign and certain malignant neoplasms of the pancreatic body and tail in specialized centers. This study evaluated safety and feasibility of a radiofrequency (RF)-assisted transection device in a porcine model of LDP. MATERIALS AND METHODS LDP was performed on 10 pigs (median weight, 39.6 kg) using a new device based on an internally cooled RF-assisted electrode (Coolinside(®), Apeiron Medical, Valencia, Spain). The animals were subjected to daily observation and then sacrificed and necropsied at 4 weeks postoperatively. Primary end points were the development of postoperative pancreatic fistula using the Pancreatic Anastomotic Leak Study Group definition and/or the presence of abdominal amylase-rich fluid collections or abscesses during necropsy and pathological study and/or dye extravasation from the pancreatic remnant duct. Secondary end points were intra- or postoperative complications, surgery, and transection duration. RESULTS No clinically relevant postoperative pancreatic fistulas were observed. In one case a grade A postoperative fistula was diagnosed due to amylase drain concentration of more than 6200 IU/mL on postoperative day 4. Median peritoneal liquid amylase concentration on postoperative day 4 was 2399.0 IU/L (range, 819.2-7122.0 IU/L), similar to the median plasma amylase level of 1520.8 IU/L (range, 1015.3-4056.6 IU/L). Median surgery time was 93.5 minutes (range, 46.0-140.0 minutes), and median transection time was 4.5 minutes (range, 2.0-26.0 minutes). There was one postoperative wound infection. There were no postoperative deaths or major complications. During the histopathological study, the surgical margin of the remaining pancreas showed a common pattern with a central area of necrosis surrounded by granulomatous infiltrate and fibrosis. Ductal obliteration was observed. No purulent inflammatory infiltrate or abscesses were present. CONCLUSION Experimental findings suggest that performing pancreatic transection with Coolinside in a animal model of LDP is feasible and safe.


International Journal of Hyperthermia | 2017

Impact of monopolar radiofrequency coagulation on intraoperative blood loss during liver resection: a prospective randomised controlled trial

Rita Quesada; Ignasi Poves; Enrique Berjano; Carles Vilaplana; Anna Andaluz; Xavier Moll; Dimitri Dorcaratto; Luis Grande; Fernando Burdío

Abstract Purpose: To evaluate the impact of using monopolar thermal coagulation based on radiofrequency (RF) currents on intraoperative blood loss during liver resection. Materials and methods: A prospective randomised controlled trial was planned. Patients undergoing hepatectomy were randomised into two groups. In the control group (n = 10), hemostasis was obtained with a combination of stitches, vessel-sealing bipolar RF systems, sutures or clips. In the monopolar radiofrequency coagulation (MRFC) group (n = 18), hemostasis was mainly obtained using an internally cooled monopolar RF electrode. Results: No differences in demographic or clinical characteristics were found between groups. Mean blood loss during liver resection in the control group was more than twice that of the MRFC group (556 ± 471 ml vs. 225 ± 313 ml, p = .02). The adjusted mean bleeding/transection area was also significantly higher in the control group (7.0 ± 3.3 ml/cm2 vs. 2.8 ± 4.0 ml/cm2, p = .006). No significant differences were observed in the rate of complications between the groups. Conclusions: The findings suggest that the monopolar electrocoagulation created with an internally cooled RF electrode considerably reduces intraoperative blood loss during liver resection.


Pancreas | 2014

Radiofrequency pancreatic ablation and section of the main pancreatic duct does not lead to necrotizing pancreatitis.

Rita Quesada; Fernando Burdío; Mar Iglesias; Dimitri Dorcaratto; Marta Cáceres; Anna Andaluz; Ignasi Poves; Tomás Castiella; Patricia Sánchez; Enrique Berjano; Luis Grande

Objective The aim of this study was to determine whether radiofrequency ablation (RFA) of the pancreas and subsequent transection of the main pancreatic duct may avoid the risk of both necrotizing pancreatitis and postoperative pancreatic fistula (POPF) formation. Methods Thirty-two rats were subjected to RFA and section of the pancreas over their portal vein. Animals were killed at 3, 7, 15, and 21 days (groups 0–3, respectively). Two additional control groups (sham operation and user manipulation only, respectively) of 15 days of postoperative period were considered. Postoperative complications, histological changes (including morphometric and immunohistochemical analysis), and incidence of POPF were evaluated. Results A significant increase in serum amylase levels (P < 0.05) on the third postoperative day, which return to baseline levels in the following weeks, was noted in groups 0 to 3. Those groups showed a rapid atrophy of the distal pancreas by apoptosis with no signs of necrotizing pancreatitis or POPF. The distal pancreas in groups 1 to 3 compared with group 0 and control groups showed a significant increase of small islets (<1000 µm2). Conclusions The rapid acinar atrophy of the distal pancreas after RFA and section of the pancreatic ducts in this model does not lead to necrotizing pancreatitis.


Scientific Reports | 2017

Long-term effectiveness of irreversible electroporation in a murine model of colorectal liver metastasis

Patricia Sánchez-Velázquez; Alberto Villanueva; Mar Iglesias; Rita Quesada; Clara Pañella; Marta Cáceres; Dimitri Dorcaratto; Anna Andaluz; Xavier Moll; Jose M. Burdio; Luis Grande; Antoni Ivorra; Fernando Burdío

Irreversible electroporation (IRE) has recently gained in popularity as an ablative technique, however little is known about its oncological long-term outcomes. To determine the long-time survival of animals treated with a high dose of IRE and which histological changes it induces in tumoral tissue, IRE ablation was performed in forty-six athymic-nude mice with KM12C tumors implanted in the liver by applying electric current with different voltages (2000 V/cm, 1000 V/cm). The tumors were allowed to continue to grow until the animals reached the end-point criteria. Histology was harvested and the extent of tumor necrosis was semi-quantitatively assessed. IRE treatment with the 2000 V/cm protocol significantly prolonged median mouse survival from 74.3 ± 6.9 days in the sham group to 112.5 ± 15.2 days in the 2000 V/cm group. No differences were observed between the mean survival of the 1000 V/cm and the sham group (83.2 ± 16.4 days, p = 0.62). Histology revealed 63.05% ± 23.12 of tumor necrosis in animals of the 2000 V/cm group as compared to 17.50% ± 2.50 in the 1000 V/cm group and 25.6% ± 22.1 in the Sham group (p = 0.001). IRE prolonged the survival of animals treated with the highest electric field (2000 V/cm). The animals in this group showed significantly higher rate of tumoral necrosis.


Pancreatology | 2015

Long-term evolution of acinar-to-ductal metaplasia and β-cell mass after radiofrequency-assisted transection of the pancreas in a controlled large animal model

Rita Quesada; Anna Andaluz; Marta Cáceres; Xavier Moll; Mar Iglesias; Dimitri Dorcaratto; Ignasi Poves; Enrique Berjano; Luis Grande; Fernando Burdío

BACKGROUND Pancreatic duct ligation (PDL) has been used as a model of chronic pancreatitis and as a model to increase β-cell mass. However, studies in mice have demonstrated acinar regeneration after PDL, questioning the long-term validity of the model. We aim to elucidate whether RF-assisted transection (RFAT) of the main pancreatic duct is a reliable PDL model, both in short (ST, 1-month) and long-term (LT, 6-months) follow-ups. METHODS Eleven pigs were subjected to RFAT. Biochemical (serum/peripancreatic amylase and glucose) and histological changes (including a semiautomatic morphometric study of over 1000 images/pancreas and IHC analysis) were evaluated after ST or LT follow-up and also in fresh pancreas specimens that were used as controls for 1 (n = 4) and 6 months (n = 6). RESULTS The distal pancreas in the ST was characterized by areas of acinar-to-ductal metaplasia (56%) which were significantly reduced at LT (21%) by fibrotic replacement and adipose tissue. The endocrine mass showed a normal increase. CONCLUSION RFAT in the pig seems to be an appropriate PDL model without restoration of pancreatic drainage or reduction of endocrine mass.


Cirugia Espanola | 2011

[Sutureless hepatic transection using a new radiofrequency assisted device. Theoretical model, experimental study and clinic trial].

María Ángeles Martínez-Serrano; Luis Grande; Fernando Burdío; Enrique Berjano; Ignasi Poves; Rita Quesada

The ideal instrument for performing hepatic transection should combine safe and rapid haemostasis in a single tool. We present a new multidisciplinary investigation designed to develop a hepatic transection device assisted by radiofrequency (RF); the investigation included: a computerised theoretical model, and experimental study and a clinical trial of this device. The theoretic modelling was performed by computer, based on the Finite Elements Method (FEM), with the objective of studying the distribution of electrical energy and temperature in the tissue, and to assess the effect of the characteristics of the instrument. The experimental study, based on an in vivo porcine model, suggested that the new instrument would allow the transection velocity of the hepatic parenchyma to be increased with lower bleeding per transection area compared with other techniques extensively used in liver surgery. These data should enable the first phase of clinical trial to be conducted, with preliminary results that suggest that the new device is safe and effective.


International Journal of Hyperthermia | 2018

A clinically oriented computer model for radiofrequency ablation of hepatic tissue with internally cooled wet electrode

Elżbieta Ewertowska; Rita Quesada; A. Radosevic; Anna Andaluz; Xavier Moll; F. García Arnas; Enrique Berjano; Fernando Burdío; Macarena Trujillo

Abstract Purpose: To improve the computer modelling of radiofrequency ablation (RFA) by internally cooled wet (ICW) electrodes with added clinically oriented features. Methods: An improved RFA computer model by ICW electrode included: (1) a realistic spatial distribution of the infused saline, and (2) different domains to distinguish between healthy tissue, saline-infused tumour, and non-infused tumour, under the assumption that infused saline is retained within the tumour boundary. A realistic saline spatial distribution was obtained from an in vivo pig liver study. The computer results were analysed in terms of impedance evolution and coagulation zone (CZ) size, and were compared to the results of clinical trials conducted on 17 patients with the same ICW electrode. Results: The new features added to the model provided computer results that matched well with the clinical results. No roll-offs occurred during the 4-min ablation. CZ transversal diameter (4.10 ± 0.19 cm) was similar to the computed diameter (4.16 cm). Including the tumour and saline infusion in the model involved (1) a reduction of the initial impedance by 10 − 20 Ω, (2) a delay in roll-off of 20 s and 70 − 100 s, respectively, and (3) 18 − 31% and 22 − 36% larger CZ size, respectively. The saline spatial distribution geometry was also seen to affect roll-off delay and CZ size. Conclusions: Using a three-compartment model and a realistic saline spatial distribution notably improves the match with the outcome of the clinical trials.


Radiology and Oncology | 2017

Focused transhepatic electroporation mediated by hypersaline infusion through the portal vein in rat model. Preliminary results on differential conductivity

Clara Pañella; Xavi Moll; Rita Quesada; Alberto Villanueva; Mar Iglesias; Dolores Naranjo; Patricia Sánchez; Anna Andaluz; Luis Grande; Antoni Ivorra; Fernando Burdío

Abstract Background Spread hepatic tumours are not suitable for treatment either by surgery or conventional ablation methods. The aim of this study was to evaluate feasibility and safety of selectively increasing the healthy hepatic conductivity by the hypersaline infusion (HI) through the portal vein. We hypothesize this will allow simultaneous safe treatment of all nodules by irreversible electroporation (IRE) when applied in a transhepatic fashion. Material and methods Sprague Dawley (Group A, n = 10) and Athymic rats with implanted hepatic tumour (Group B, n = 8) were employed. HI was performed (NaCl 20%, 3.8 mL/Kg) by trans-splenic puncture. Deionized serum (40 mL/Kg) and furosemide (2 mL/Kg) were simultaneously infused through the jugular vein to compensate hypernatremia. Changes in conductivity were monitored in the hepatic and tumour tissue. The period in which hepatic conductivity was higher than tumour conductivity was defined as the therapeutic window (TW). Animals were monitored during 1-month follow-up. The animals were sacrificed and selective samples were used for histological analysis. Results The overall survival rate was 82.4% after the HI protocol. The mean maximum hepatic conductivity after HI was 2.7 and 3.5 times higher than the baseline value, in group A and B, respectively. The mean maximum hepatic conductivity after HI was 1.4 times higher than tumour tissue in group B creating a TW to implement selective IRE. Conclusions HI through the portal vein is safe when the hypersaline overload is compensated with deionized serum and it may provide a TW for focused IRE treatment on tumour nodules.


International Journal of Hyperthermia | 2016

Radiofrequency-induced heating versus mechanical stapler for pancreatic stump closure: in vivo comparative study

Fernando Burdío; Dimitri Dorcaratto; Lourdes Hernández; Anna Andaluz; Xavier Moll; Rita Quesada; Ignasi Poves; Luis Grande; Marta Cáceres; Enrique Berjano

Abstract Purpose: The aim of this study was to assess the capacity of two methods of surgical pancreatic stump closure in terms of reducing the risk of pancreatic fistula formation (POPF): radiofrequency-induced heating versus mechanical stapler. Materials and methods: Sixteen pigs underwent a laparoscopic transection of the neck of the pancreas. Pancreatic anastomosis was always avoided in order to work with an experimental model prone to POPF. Pancreatic stump closure was conducted either by stapler (ST group, n = 8) or radiofrequency energy (RF group, n = 8). Both groups were compared for incidence of POPF and histopathological alterations of the pancreatic remnant. Results: Six animals (75%) in the ST group and one (14%) in the RF group were diagnosed with POPF (p = 0.019). One animal in the RF group and three animals in the ST group had a pseudocyst in close contact with both pancreas stumps. On day 30 post-operation (PO), almost complete atrophy of the exocrine distal pancreas was observed when the main pancreatic duct was efficiently sealed. Conclusions: Our findings suggest that RF-induced heating is more effective at closing the pancreatic stump than mechanical stapler and leads to the complete atrophy of the distal remnant pancreas.

Collaboration


Dive into the Rita Quesada's collaboration.

Top Co-Authors

Avatar

Fernando Burdío

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar

Enrique Berjano

Polytechnic University of Valencia

View shared research outputs
Top Co-Authors

Avatar

Luis Grande

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar

Anna Andaluz

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar

Ignasi Poves

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar

Dimitri Dorcaratto

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar

Mar Iglesias

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar

Xavier Moll

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge