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Dive into the research topics where Tommy Kjærgaard Nielsen is active.

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Featured researches published by Tommy Kjærgaard Nielsen.


Scandinavian Journal of Urology and Nephrology | 2015

Reducing recurrence in non-muscle-invasive bladder cancer using photodynamic diagnosis and immediate post-transurethral resection of the bladder chemoprophylaxis.

Malene Risager Lykke; Tommy Kjærgaard Nielsen; Nanna Andersen Ebbensgaard; Karsten Zieger

Abstract Objective. The aim of this study was to evaluate the effect of fluorescence cystoscopy and immediate post-transurethral resection of the bladder (TURB) chemoprophylaxis on the risk of recurrence of non-muscle-invasive bladder cancer (NMIBC) under routine clinical conditions. Materials and methods. Fluorescence cystoscopy using hexyl-aminolevulinate and post-TURB chemoprophylaxis using mitomycin C were simultaneously introduced in an effort to reduce the recurrence of NMIBC. In total, 190 consecutive patients were enrolled over a 2 year period and followed as the intervention group; 216 patients treated over a 2 year period before introduction served as controls. An intention-to-treat analysis was performed with baseline control. Results. The recurrence risk was reduced by 41% (hazard ratio 0.59, 95% confidence interval 0.45–0.78) (intention-to-treat analysis). Median recurrence-free survival was extended from 13.6 months to 36.8 months. Every third follow-up TURB was avoided. Patients with low-risk tumors and patients with primary as well as recurrent disease benefited from the treatment. Conclusions. Fluorescence cystoscopy and immediate post-TURB chemoprophylaxis effectively reduced the recurrence risk and numbers of follow-up procedures under clinical routine conditions.


Journal of Endourology | 2015

Computed Tomography Contrast Enhancement Following Renal Cryoablation—Does it Represent Treatment Failure?

Tommy Kjærgaard Nielsen; Øyvind Østraat; Gratien Andersen; Søren Høyer; Ole Graumann; Michael Borre

OBJECTIVE For minimal invasive treatment of small renal masses, cryoablation has gained popularity. Treatment success is defined as the absence of contrast enhancement on postoperative imaging of the cryoablated lesion, but contrast enhancement does not necessarily equal treatment failure. This present study investigates the proportion of spontaneous resolutions after initial contrast enhancement in relation to cryoablation. MATERIALS AND METHODS Data were collected from a prospectively maintained clinical database containing all patients treated with primary laparoscopic and percutaneous cryoablation between August 2005 and December 2013. All images were evaluated with regard to preoperative aspects and dimensions used for an anatomical classification (PADUA) score, cryolesion size, contrast enhancement pattern, and tissue density. RESULTS A total of 107 patients with a biopsy-verified malignant tumor were included in the study. On postoperative imaging, 33 (31%) patients presented with contrast enhancement. Spontaneous resolution was observed in 15 (45%) patients after a mean follow-up time of 14 months. Patients with cryolesions that resolved spontaneously were found to have a less anatomical complex tumor compared to patients with treatment failure (PADUA 7.8 vs 9.5, p < 0.01). A total of seven patients with a PADUA score ≥10 and contrast-enhancing cryolesions were found to have treatment failure. No association was found among body mass index, histology, treatment modality, enhancement pattern, number of applied cryoprobes, and resolution. CONCLUSION Postoperative contrast enhancement is commonly observed after cryoablation and a large portion of these lesions often resolves spontaneously, thus not representing treatment failure. In patients with a high preoperative PADUA score and postoperative contrast enhancement of the cryolesion, treatment failure or recurrent disease should be suspected.


BJUI | 2017

Oncological outcomes and complication rates after laparoscopic-assisted cryoablation: a European Registry for Renal Cryoablation (EuRECA) multi-institutional study

Tommy Kjærgaard Nielsen; Brunolf W. Lagerveld; Francis X. Keeley; Giovanni Lughezzani; Seshadri Sriprasad; Neil J. Barber; Lars Ulrich Hansen; Nicole M Buffi; Giorgio Guazzoni; Johan A. van der Zee; Mohamed Ismail; Khaled Farrag; Amr M Emara; Lars Lund; Øyvind Østraat; Michael Borre

To assess complication rates and intermediate oncological outcomes of laparoscopic‐assisted cryoablation (LCA) in patients with small renal masses (SRMs).


Technology in Cancer Research & Treatment | 2017

Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model

Tommy Kjærgaard Nielsen; Øyvind Østraat; Ole Graumann; Bodil Ginnerup Pedersen; Gratien Andersen; Søren Høyer; Michael Borre

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention, each animal was randomized to a postoperative follow-up period of 1, 2, or 4 weeks, after which computed tomography perfusion and magnetic resonance imaging scans were performed. Immediately after imaging, open bilateral nephrectomy was performed allowing for histopathological examination of the cryolesions. On computed tomography perfusion and magnetic resonance imaging examinations, rim enhancement was observed in the transition zone of the cryolesion 1week after laparoscopic-assisted cryoablation. This rim enhancement was found to subside after 2 and 4 weeks of follow-up, which was consistent with the microscopic examinations revealing of fibrotic scar tissue formation in the peripheral zone of the cryolesion. On T2 magnetic resonance imaging sequences, a thin hypointense rim surrounded the cryolesion, separating it from the adjacent renal parenchyma. Microscopic examinations revealed hemorrhage and later hemosiderin located in the peripheral zone. No nodular or diffuse contrast enhancement was found in the central zone of the cryolesions at any follow-up stage on neither computed tomography perfusion nor magnetic resonance imaging. On microscopic examinations, the central zone was found to consist of coagulative necrosis 1 week after laparoscopic-assisted cryoablation, which was partially replaced by fibrotic scar tissue 4 weeks following laparoscopic-assisted cryoablation. Both computed tomography perfusion and magnetic resonance imaging found the renal collecting system to be involved at all 3 stages of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings but with some differences, especially regarding the peripheral zone. Magnetic resonance imaging seems an attractive modality for early postoperative follow-up.


Journal of Endourology | 2016

Preoperative Aspects and Dimensions Used for Anatomical Score Predicts Treatment Failures in Laparoscopic Cryoablation of Small Renal Masses.

Tommy Kjærgaard Nielsen; Brunolf W. Lagerveld; Øyvind Østraat; Gratien Andersen; Søren Høyer; Johan van der Zee; Lasse Larsen Nonboe; Ole Graumann; Michael Borre

OBJECTIVES To determine the potential of the preoperative aspects and dimensions used for anatomical (PADUA) classification score as a predictive tool in relation to residual unablated tumor and disease-free survival (DFS) following laparoscopy-assisted cryoablation (LCA) of small renal masses. PATIENTS AND METHODS A multi-institutional cohort of 212 patients with biopsy-verified T1N0M0 renal malignancies treated with LCA between August 2005 and September 2014 were retrospectively investigated with respect to oncologic outcomes. RESULTS The preoperative PADUA score was found to be low (6-7 points) in 70 patients (33%), moderate (8-9 points) in 86 patients (40.6%), and high (10-14 points) in 56 patients (26.4%). The mean PADUA score was significantly higher in cases (n = 11) with residual unablated tumor (10.4 vs 8.1, p < 0.001) and in cases (n = 8) with local tumor recurrence (9.8 vs 8.1, p < 0.001) at a mean follow-up of 37 (95% confidence interval: 34-40) months. The estimated 2-, 3-, and 5-year DFS for patients with a moderate PADUA score was 96%, 94%, and 94% compared with 95%, 87%, and 81%, respectively, for patients with a high PADUA score (log-rank, p = 0.003). The PADUA score did not predict overall survival. CONCLUSION The PADUA score significantly predicts residual unablated tumor and DFS following LCA. Further studies are needed to validate the efficacy of the PADUA score in relation to oncologic outcomes following ablative procedures.


Cryobiology | 2018

Renal cryoablation: Multidisciplinary, collaborative and perspective approach

Mohamed Ismail; Tommy Kjærgaard Nielsen; Brunolf W. Lagerveld; Julien Garnon; David J Breen; Alexander J. King; Marco Van Strijen; Francis X. Keeley

Renal cryoablation is becoming an established treatment option for small renal masses. It allows preservation of renal function without compromising cancer control. The technique has evolved considerably since it was first reported using liquid nitrogen over 20 years ago. We describe the modern technique for both laparoscopic and image guided renal cryoablation. Renal cryoablation is performed either laparoscopically or percutaneously depending on tumour characteristics. Common features include biopsy of the mass, protection of adjacent organs, and the use of compressed argon gas for freezing and helium for thawing. Dynamic monitoring is used to ensure adequate treatment. The shape of the iceball can be modified by adding extra needles or changing their positions. A double freeze/thaw is necessary for confident ablation of all cancer cells. The laparoscopic approach includes exposure of the tumour and may involve extensive mobilisation of the kidney. Laparoscopic ultrasound is essential for correct localisation of the tumour, needle placement, and monitoring the treatment. A Temperature probe is placed at the edge of the tumour to record treatment temperature. The percutaneous approach is typically performed with CT guidance. Adjacent organs can be protected by injecting saline or carbon dioxide. Early imaging is helpful to detect or rule out incomplete treatment. Post-operative follow-up is structured at specific intervals (e.g. 3, 6, 12 months then annually) and perhaps tailored or modified based on the degree of suspicion of inadequate treatment.


Technology in Cancer Research & Treatment | 2017

Arterial Clamping Increases Central Renal Cryoablation Efficacy: An Animal Study

Lasse Larsen Nonboe; Tommy Kjærgaard Nielsen; Søren Høyer; Ole Graumann; Jørgen Frøkiær; Michael Borre

Introduction: The minimally invasive treatment of small renal masses with cryoablation has become increasingly widespread during the past 15 years. Studies with long-term follow-up are beginning to emerge, showing good oncological control, however, tumors with a central and endophytic location seem to possess an increased risk of treatment failure. Such tumors are likely to be subjected to a high volume of blood giving thermal protection to the cancerous cells. Arterial clamping during freezing might reduce this effect but at the same time subject the kidney to ischemia. The aim of this study was to evaluate the effect of renal artery clamping during cryoablation in a porcine survival model. Methods: Ten Danish Landrace pigs (approximately 40 kg) underwent bilateral laparoscopic cryoablation with clamping of the right renal artery during freezing. The cryoablation consisted of a standard double-freeze cycle of 10-minute freeze followed by 8 minutes of thaw. Arterial clamping subjected the right kidney to 2 cycles of ischemia (10 minutes) with perfusion in between. After surgery, the animals were housed for 14 days prior to computed tomography perfusions scans, radioisotope renography, and bilateral nephrectomy. Results: No perioperative or postoperative complications were experienced. Mean differential renal function was 44% (95% confidence interval: 42-46) in the clamped right kidney group and 56% (95% confidence interval: 54-58) in the nonclamped left kidney group, P < .05. The ±5% technical inaccuracy is not accounted for in the results. Mean maximum temperature between freeze cycles was 5.13°C (95% confidence interval: −0.1 to 10.3) in the clamped right kidney group and 22.7°C (95% confidence interval: −16.6 to 28.8) in the nonclamped left kidney group, P < .05. Mean cryolesion volume, estimated on computed tomography perfusion, was 12.4 mL (95% confidence interval: 10.35-14.4) in the clamped right kidney group and 6.85 mL (95% confidence interval: 5.57-8.14) in the nonclamped left kidney group, P < .05. Pathological examination shows a higher degree of vital cells in the intermediate zone of the cryolesions in the nonclamped left kidneys when compared with the clamped right kidneys. Conclusion: Arterial clamping increases cryolesion size by approximately 80%, and pathologic examinations suggest a decreased risk of vital cells in the intermediate zone. The clamped kidneys showed no sign of injury from the limited ischemic insult. This study was limited by being a nontumor model.


Journal of Endourology | 2018

Laparoscopic vs Percutaneous Cryotherapy for Renal Tumors: A Systematic Review and Meta-Analysis.

Omar M. Aboumarzouk; Mohamed Ismail; David J Breen; Marco Van Strijen; Julien Garnon; Brunolf W. Lagerveld; Tommy Kjærgaard Nielsen; Francis X. Keeley

BACKGROUND Cryoablation has emerged as an alternative to the more invasive partial nephrectomy for small renal masses. The approach can be carried out by two techniques, either laparoscopic cryoablation (LCA) or percutaneous cryoablation, (PCA) with CT guidance. We aimed to compare between the two procedures. MATERIALS AND METHODS A systematic review and meta-analysis was conducted, including studies comparing the two techniques. Outcomes included incomplete ablation, late local recurrence, cancer-specific survival, procedure time, transfusion rates, hospital stay, and complications. RESULTS A total of 1475 patients were included, 788 patients in the laparoscopic group and 687 patients in the percutaneous group. There was statistical difference favoring the laparoscopic group with regard to having less incomplete ablation (p = 0.0008) and higher cancer-specific survival patients (p = 0.04). However, there was longer hospital stays in the LCA group (p < 0.00001) and was found to be more costly than the PCA group. There was significantly more Clavien-I complications in the PCA group (p = 0.001) and more Clavien-III complications in the LCA group (p = 0.001). Otherwise, there were no differences in any other outcome parameter. CONCLUSION LCA was found to have less incomplete tumor ablation rates and higher cancer-specific survival rates, however, higher hospitalization time, more major complications (Clavien III), and was costlier compared with PCA.


Acta Radiologica | 2018

Short-term complications for percutaneous ultrasound-guided biopsy of renal masses in adult outpatients

Lars René Rasmussen; Martina Loft; Tommy Kjærgaard Nielsen; Marie Bjødstrup Jensen; Søren Høyer; Arne Hørlyck; Ole Graumann

Background Ultrasound-guided percutaneous kidney tumor biopsy (UGPKB) plays an important role in the diagnosis of renal tumor but there are no consensuses with respect to the length and the extend of the post-biopsy observation period. Purpose To assess the short-term complication rate after UGPKB and to evaluate whether the onset of complications allows for the procedure to be performed in an outpatient setting with same-day discharge. Material and Methods Between March 2012 and March 2014, a total of 287 UGPKB were performed in an outpatient setting at a Danish university referral center. All patient records were retrospectively reviewed and post-biopsy complications as well as biochemical parameters were registered. Results The overall complication rate was 3.8% (11 patients). Major complications occurred in 1.0% of all cases (three patients); one patient with ongoing bleeding that required intervention and two patients with septicemia. Minor complications occurred in 2.8% of cases (eight patients); six patients with self-limiting gross hematuria, one patient with small asymptomatic subcapsular hematoma, and one patient with vasovagal syncope. The timing of both minor and major complication onset ranged from the time of biopsy and up to four days after discharge. Conclusion UGPKB of indeterminate renal masses in adult patients in an outpatient setting appears to be a safe procedure with a very low rate of major complications. Same-day discharge after renal mass biopsy seems feasible.


Archive | 2017

Laparoscopic versus percutaneous cryotherapy for renal tumours: a systematic review and meta-analysis

Omar M. Aboumarzouk; Mohamed Ismail; David J Breen; Marco Van Strijen; Julein Garnon; Brunolf W. Lagerveld; Tommy Kjærgaard Nielsen; Francis X. Keeley

BACKGROUND Cryoablation has emerged as an alternative to the more invasive partial nephrectomy for small renal masses. The approach can be carried out by two techniques, either laparoscopic cryoablation (LCA) or percutaneous cryoablation, (PCA) with CT guidance. We aimed to compare between the two procedures. MATERIALS AND METHODS A systematic review and meta-analysis was conducted, including studies comparing the two techniques. Outcomes included incomplete ablation, late local recurrence, cancer-specific survival, procedure time, transfusion rates, hospital stay, and complications. RESULTS A total of 1475 patients were included, 788 patients in the laparoscopic group and 687 patients in the percutaneous group. There was statistical difference favoring the laparoscopic group with regard to having less incomplete ablation (p = 0.0008) and higher cancer-specific survival patients (p = 0.04). However, there was longer hospital stays in the LCA group (p < 0.00001) and was found to be more costly than the PCA group. There was significantly more Clavien-I complications in the PCA group (p = 0.001) and more Clavien-III complications in the LCA group (p = 0.001). Otherwise, there were no differences in any other outcome parameter. CONCLUSION LCA was found to have less incomplete tumor ablation rates and higher cancer-specific survival rates, however, higher hospitalization time, more major complications (Clavien III), and was costlier compared with PCA.

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Ole Graumann

Odense University Hospital

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David J Breen

Southampton General Hospital

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Michael Borre

Aarhus University Hospital

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Francis X. Keeley

Thomas Jefferson University

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Francis X. Keeley

Thomas Jefferson University

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