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Dive into the research topics where N.M.A. Krekel is active.

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Featured researches published by N.M.A. Krekel.


Ejso | 2011

Optimising surgical accuracy in palpable breast cancer with intra-operative breast ultrasound – Feasibility and surgeons’ learning curve

N.M.A. Krekel; A.M.F. Lopes Cardozo; S. Muller; Elisabeth Bergers; Sybren Meijer; M.P. van den Tol

AIMS To evaluate if intra-operative guidance with ultrasonography (US) could improve surgical accuracy of palpable breast cancer excision, and to evaluate the performance of surgeons during training for US-guided excision. MATERIALS AND METHODS Thirty female patients undergoing breast-conserving surgery for palpable T1-T2 invasive breast cancer were recruited. Three individual breast surgeons, assisted by US, targeted and excised the tumours. The main objective was to obtain adequate resection margins with optimal resection volumes. The specimen volume, tumour diameter and histological margin status were recorded. The specimen volume was divided by the optimal resection volume, defined as the spherical tumour volume plus a 1.0-cm margin. The resulting calculated resection ratio (CRR) indicated the amount of excess tissue resected. RESULTS All tumours were correctly identified during surgery, 29 of 30 tumours (96.7%) were removed with adequately negative margins, and one tumour was removed with focally positive margins. The median CRR was 1.0 (range, 0.4-2.8), implying optimal excision volume. For all breast surgeons, CRR improved during the training period. By the 8th procedure, all surgeons showed proficiency in performing intra-operative breast US. CONCLUSION Surgeons can easily learn the skills needed to perform intra-operative US for palpable breast tumour excision. The technique is non-invasive, simple, safe and effective for obtaining adequate resection margins. Within the first two cases, resections reached optimal volumes, thereby, presumably resulting in improved cosmetic outcomes. In a multicentre, randomised, clinical trial, intra-operative US guidance for palpable breast tumours will be evaluated for oncological and cosmetic outcomes.


BMC Surgery | 2011

Ultrasound-guided breast-sparing surgery to improve cosmetic outcomes and quality of life. A prospective multicentre randomised controlled clinical trial comparing ultrasound-guided surgery to traditional palpation-guided surgery (COBALT trial)

N.M.A. Krekel; Barbara M Zonderhuis; Hermien Schreurs; Alexander Mf Lopes Cardozo; Herman Rijna; Henk van der Veen; S. Muller; Pieter Poortman; Louise de Widt; Wilfred K de Roos; A.M. Bosch; Annette H. M. Taets van Amerongen; Elisabeth Bergers; Mecheline Van Der Linden; Elly Sm de Lange de Klerk; Henri A. H. Winters; Sybren Meijer; Petrousjka van den Tol

BackgroundBreast-conserving surgery for breast cancer was developed as a method to preserve healthy breast tissue, thereby improving cosmetic outcomes. Thus far, the primary aim of breast-conserving surgery has been the achievement of tumour-free resection margins and prevention of local recurrence, whereas the cosmetic outcome has been considered less important. Large studies have reported poor cosmetic outcomes in 20-40% of patients after breast-conserving surgery, with the volume of the resected breast tissue being the major determinant. There is clear evidence for the efficacy of ultrasonography in the resection of nonpalpable tumours. Surgical resection of palpable breast cancer is performed with guidance by intra-operative palpation. These palpation-guided excisions often result in an unnecessarily wide resection of adjacent healthy breast tissue, while the rate of tumour-involved resection margins is still high. It is hypothesised that the use of intra-operative ultrasonography in the excision of palpable breast cancer will improve the ability to spare healthy breast tissue while maintaining or even improving the oncological margin status. The aim of this study is to compare ultrasound-guided surgery for palpable tumours with the standard palpation-guided surgery in terms of the extent of healthy breast tissue resection, the percentage of tumour-free margins, cosmetic outcomes and quality of life.Methods/designIn this prospective multicentre randomised controlled clinical trial, 120 women who have been diagnosed with palpable early-stage (T1-2N0-1) primary invasive breast cancer and deemed suitable for breast-conserving surgery will be randomised between ultrasound-guided surgery and palpation-guided surgery. With this sample size, an expected 20% reduction of resected breast tissue and an 18% difference in tumour-free margins can be detected with a power of 80%. Secondary endpoints include cosmetic outcomes and quality of life. The rationale, study design and planned analyses are described.ConclusionThe COBALT trial is a prospective, multicentre, randomised controlled study to assess the efficacy of ultrasound-guided breast-conserving surgery in patients with palpable early-stage primary invasive breast cancer in terms of the sparing of breast tissue, oncological margin status, cosmetic outcomes and quality of life.Trial Registration NumberNetherlands Trial Register (NTR): NTR2579


The Breast | 2013

Ultrasound-guided surgery for palpable breast cancer is cost-saving: Results of a cost-benefit analysis

M.H. Haloua; N.M.A. Krekel; Veerle M.H. Coupé; J.E. Bosmans; A.M.F. Lopes Cardozo; Sybren Meijer; M.P. van den Tol

Ultrasound-guided surgery (USS) has recently been proven to result in a significant reduction of tumour-involved surgical margins, for patients with palpable invasive breast cancer. The objective of this economic evaluation alongside a randomised trial was to evaluate the costs and benefits of USS compared to palpation-guided surgery (PGS). The hospital perspective was used. On the cost side of the analysis, resource use related to baseline treatment was taken into account and on the benefit side, resource use related to additional treatments was included. On the cost side, the difference in costs per patient was €193 (95% CI €153-€233) with higher costs in the USS group. On the benefit side, the difference in costs per patient was -€349 (95% CI -€591 to -€103) with higher costs in the PGS group. This resulted in a cost decrease of -€154 (95% CI -€388 to €81) in the USS group compared to the PGS group. Intra-operative use of a US system during BCS reduces the rate of tumour-involved margins and thereby the costs of additional treatments.


Cancer Research | 2012

Abstract PD04-01: Intra-operative ultrasound in breast-conserving surgery for palpable breast cancer significantly improves both surgical accuracy and cosmetic outcome while saving costs.

M.H. Haloua; N.M.A. Krekel; Veerle M.H. Coupé; P van den Tol; S. Meijer

Background: Breast-conserving surgery for palpable breast cancer is worldwide associated with a high rate of tumour-involved margins and excessive healthy tissue resection. This results in additional treatment and poor cosmetic outcome. Ultrasound-guided surgery (USS) may resolve both problems by improving surgical accuracy. A randomised controlled trial was initiated to compare USS with the standard palpation-guided surgery (PGS) for palpable breast cancer. Methods: A total of 134 eligible patients with palpable T1-T2 invasive breast cancer were randomised to either USS (n = 65) or PGS (n = 69). Outcome measures included resection margin status, re-excision rates, mastectomy rates and additional radiotherapy. A calculated resection ratio (CRR) was derived from specimen volumes and tumour diameters, indicating healthy tissue resection. Secondary outcome measures were operative time, complications cosmetic outcome and cost-effectiveness. The costs of purchasing the US-system were included in the USS-group. The mean total costs per patient were calculated and compared between both study groups. Results: In the USS-group, 3.1% of margins were involved, compared with 17.4% in the PGS-group (p = 0.009). The use of intra-operative US resulted in a significant reduction in additional therapies (p = 0.015); in the PGS-group re-excisions were necessary in 3 patients (4.3%) and in 1 patient (1.5%) in the USS-group, mastectomies were performed in 5 patients (7.2%) of the PGS-group and in none of the patients of the USS-group, and additional radiotherapy boosts in 11 patients (15.9%) of the PGS-group and 6 patients in the USS-group (9.2%). Excision volumes and CRR were both reduced with USS (38cc vs. 58cc and 1.0 vs. 1.7, respectively; both P Conclusion: USS can prevent the unacceptably high rate of tumour-involved resection margins in palpable breast cancer excision, thus not only improving oncological and cosmetic outcomes by avoiding subsequent surgery or radiotherapy, but also considerably reducing treatment costs. In addition to palpable breast cancer surgery, USS might be used for non-papable breast cancer surgery, mastectomies and oncoplastic procedures. Therefore even greater cost-savings might be achieved by using a US-system for breast cancer surgery. Long term results of cosmetic outcome and quality of life of this trial are expected in 2013. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD04-01.


Microsurgery | 2018

Intraoperative evaluation of perfusion in free flap surgery: A systematic review and meta-analysis

Jan Maerten Smit; Vera L. Negenborn; Sanne M. Jansen; Mariëlle E. H. Jaspers; Ralph de Vries; Martijn W. Heymans; Hay A. H. Winters; Ton G. van Leeuwen; Margriet G. Mullender; N.M.A. Krekel

Free flap survival relies on adequate tissue perfusion. We aim to give an overview of the available literature of all objective methods to intraoperatively assess free flap tissue perfusion, and the effects on (partial) flap loss.


Nederlands Tijdschrift voor Geneeskunde | 2012

Mammasparende chirurgie voor borstkanker: er is nog winst te behalen

N.M.A. Krekel; M.H. Haloua; S. Muller; E. Bergers; D.H.F. Rietveld; S. Meijer; M.P. van den Tol; Vu; Vu medisch centrum


European Journal of Cancer | 2012

1LBA Intra-operative Ultrasound is Imperative to Obtain Adequate Tumour Margins and Excision Volumes in Breast-conserving Surgery for Palpable Breast Cancer: Results of a Randomised Controlled Trial

N.M.A. Krekel; M.H. Haloua; A.M.F. Lopes Cardozo; A.M. Bosch; S. Muller; L. de Widt; A.H.M. Taets van Amerongen; E. Bergers; S. Meijer; M.P. van den Tol


Journal of Plastic Reconstructive and Aesthetic Surgery | 2017

Breast-conserving therapy for breast cancer: Cosmetic results and options for delayed reconstruction

Vera L. Negenborn; José H. Volders; N.M.A. Krekel; Max H. Haloua; Mark-Bram Bouman; Marlon E. Buncamper; Frank B. Niessen; Hay A. H. Winters; Caroline B. Terwee; Sybren Meijer; M.Petrousjka van den Tol


Oncologie Up-to-date | 2012

Echogeleide borstsparende chirurgie beter dan palpatiegeleide ingreep

N.M.A. Krekel; A.M. Lopez Cardoso; R.H. de Wit; S. Muller; H. van der Veen; A.M. Bosch; W.K. de Roos; L. Widt; Pieter Poortman; Herman Rijna; A.H.M. Taets van Amerongen; E. Bergers; E.S.M. de Lange-de Klerk; S. Meijer; M.P. van den Tol


Nederlands Tijdschrift voor Geneeskunde | 2012

Echogeleide borstsparende chirurgie voor palpabele mammacarcinomen

N.M.A. Krekel; A.H.M. Taets van Amerongen; E. Bergers; S. Meijer; M.P. van den Tol; Vu; Vu medisch centrum

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M.P. van den Tol

VU University Medical Center

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S. Meijer

VU University Medical Center

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S. Muller

VU University Medical Center

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E. Bergers

VU University Medical Center

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M.H. Haloua

VU University Medical Center

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Veerle M.H. Coupé

VU University Medical Center

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