Prevention of Seroma Formation and Its Sequelae After Axillary Lymph Node Dissection: An Up-to-Date Systematic Review and Guideline for Surgeons.

INTRODUCTION: Seroma formation after axillary lymph node dissection (ALND) remains a troublesome complication with significant morbidity. Numerous studies have tried to identify techniques to prevent seroma formation. The aim of this systematic review and network meta-analysis is to use available literature to identify the best intervention for prevention of seroma after standalone ALND. METHODS: A literature search was performed for all comparative articles regarding seroma formation in patients undergoing a standalone ALND or ALND with breast-conserving surgery in the last 25 years. Data regarding seroma formation, clinically significant seroma (CSS), surgical site infections (SSI), and hematomas were collected. The network meta-analysis was performed using a random effects model and the level of inconsistency was evaluated using the Bucher method. RESULTS: A total of 19 articles with 1962 patients were included. Ten different techniques to prevent seroma formation were described. When combining direct and indirect comparisons, axillary drainage until output is less than 50 ml per 24 h for two consecutive days results in significantly less CSS. The use of energy sealing devices, padding, tissue glue, or patches did not significantly reduce the incidence of CSS. When comparing the different techniques with regard to SSIs, no statistically significant differences were seen. CONCLUSIONS: To prevent CSS after ALND, axillary drainage is the most valuable and scientifically proven measure. On the basis of the results of this systematic review with network meta-analysis, removing the drain when output is < 50 ml per 24 h for two consecutive days irrespective of duration seems best. Since drainage policies vary widely, an evidence-based guideline is needed.

Drain-free mastectomy and flap fixation: The interim analysis of a randomized controlled noninferiority trial.

INTRODUCTION: Flap fixation after mastectomy has proven to be one of the most promising solutions to reduce seroma formation. Drain placement remains standard practice in many clinics, even though this may be redundant after flap fixation. METHODS: This is a prospective randomized controlled trial comparing mastectomy and wound closure using flap fixation with or without drain placement. The primary outcome measure was clinically significant seroma (CSS) incidence. The aim of this interim analysis was to assess the assumptions for the sample size calculation and to provide preliminary results. RESULTS: Between July 2020 and January 2023, 112 patients were included. CSS incidence was 9.1% in the drain group and 21% in the no-drain group. In total, 10 patients were lost to follow-up. These numbers are similar to the ones used for the sample size calculation. In the drain group, three patients required interventions for wound complications compared to nine in the no-drain group (odds ratio: 3.612 [95% confidence interval: 0.898-14.537]). CONCLUSION: The sample size calculation seems to be correct and no protocol amendments are necessary. Current preliminary results show no significant differences in CSS incidence. Complete results should be awaited to draw a well-powered conclusion regarding drain policy after mastectomy.

Seroma formation after mastectomy: A systematic review and network meta-analysis of different flap fixation techniques.

Flap fixation is the most promising solution to prevent seroma formation after mastectomy. In this systematic review with network meta-analysis (NMA), three different techniques were compared. The NMA included 25 articles, comprising 3423 patients, and revealed that sutures are superior to tissue glue in preventing clinically significant seroma. In addition, running sutures seemed to be superior to interrupted sutures. An RCT comparing these suture techniques seems necessary, given the quality and nature of existing literature.

Bupivacaine pleural effusion mimicking a hemothorax after a thoracoscopic microdiscectomy with epidural anesthesia.

PURPOSE: Post-operative pain after video-assisted thoracoscopic surgery is often treated using thoracic epidural analgesics or thoracic paravertebral analgesics. This article describes a case where a thoracic disc herniation is treated with a thoracoscopic microdiscectomy with post-operative thoracic epidural analgesics. The patient developed a bupivacaine pleural effusion which mimicked a hemothorax on computed tomography (CT). METHODS: The presence of bupivacaine in the pleural effusion was confirmed using a high performance liquid chromatography method. RESULTS: The patient underwent a re-exploration to relieve the pleural effusion. The patient showed a long-term recovery similar to what can be expected from an uncomplicated thoracoscopic microdiscectomy. CONCLUSION: A pleural effusion may occur when thoracic epidural analgesics are used in patents with a corridor between the pleural cavity and epidural space.

Impact of analysis of the sentinel lymph node by one-step nucleic acid amplification (OSNA) compared to conventional histopathology on axillary and systemic treatment: data from the Dutch nationwide cohort of breast cancer patients.

PURPOSE: The outcome of the sentinel lymph node in breast cancer patients affects adjuvant treatment. Compared to conventional histopathology, analysis by one-step nucleic acid amplification (OSNA) harvests more micrometastasis, potentially inducing overtreatment. In this study we investigated the impact of OSNA analysis on adjuvant treatment, compared to histopathological analysis. METHODS: Data from T1-3 breast cancer patients with sentinel nodes analysed between January 2016 and December 2019 by OSNA (OSNA group, n = 1086) from Zuyderland Medical Centre, the Netherlands, were compared to concurrent data from the Netherlands Cancer Registry (NKR) where sentinel nodes were examined by histology (histology group, n = 35,143). Primary outcomes were micro- or macrometastasis, axillary treatments (axillary lymph node dissection (ALND) or axillary radiotherapy (ART)), chemotherapy, and endocrine therapy. Statistics with Pearson Chi-square. RESULTS: In the OSNA group more micrometastasis (14.9%) were detected compared to the histology group (7.9%, p < 0.001). No difference in axillary treatment between groups was detected (14.3 vs. 14.4%). In case of mastectomy and macrometastasis, ALND was preferred over ART in the OSNA group (14.9%) compared to the histology group (4.4%, p < 0.001). In cases of micrometastasis, no difference was seen. There was no difference in administration of adjuvant chemotherapy between groups. Endocrine treatment was administrated less often in the OSNA group compared to the histology group (45.8% vs. 50.8%, p < 0.002). CONCLUSION: More micrometastasis were detected by OSNA compared to histopathology, but no subsequent increase in adjuvant axillary and systematic treatment was noticed. When performing mastectomy and OSNA, there was a preference for ALND compared to ART.

An adapted protocol for magnetic localisation of nonpalpable breast cancer lesions and sentinel lymph nodes using a magnetic seed and superparamagnetic iron oxide tracer.

BACKGROUND: Localisation techniques for nonpalpable breast cancer lesions and sentinel lymph node biopsy (SLNB) are associated with several drawbacks. A complete magnetic technique using magnetic seeds and superparamagnetic iron oxide tracer could be an interesting alternative. This study describes a clear protocol and the results of a combined magnetic approach. METHODS: From August 2021 to February 2022 40 patients undergoing breast conserving surgery with SLNB were eligible for inclusion. Localisation was performed under ultrasound or stereotactic guidance, 1 week before surgery. Subsequently, 1 ml of tracer was injected at least 4 cm away from the tumour. Technetium-99m (99m Tc) was injected 1 day before surgery as control procedure. Outcomes were SLNB time, a number of nodes detected with magnetic tracer including comparison with 99m Tc, a success rate of malignant lesion detection and pathological margin assessment. RESULTS: In total, 40 procedures were performed on 39 patients. A median of one node was retrieved. Sentinel nodes were retrieved using MagTrace® with a 92.5% detection rate compared to 99m Tc. Wide local excision under magnetic guidance was successful in 35 cases. CONCLUSIONS: This paper describes a combined magnetic approach for breast-conserving surgery and SLNB. An adapted protocol is described and could be used for implementation.

Delayed presentation of manubriosternal dislocation after thoracolumbar spondylodesis in a polytrauma patient - a case report.

BACKGROUND: Manubriosternal dislocations are a rare entity and frequently associated with thoracic spine fractures and, in minority of cases, with cervical or thoracolumbar fractures. METHODS: Our case represents a 38-year-old male who fell from a height resulting in multiple fractures, amongst others of the first lumbar vertebra. At primary survey and computed tomography scan no manubriosternal injury was apparent. After posterior stabilization of the thoracolumbar vertebrae a manubriosternal dislocation was identified and stabilized using plate-and-screw fixation. RESULTS: Clinical findings of a manubriosternal dislocation are not always obvious, allowing them to be missed at initial assessment. CONCLUSIONS: Manubriosternal dislocations can be missed at the initial investigation, even on cross-sectional imaging, and only become visible after spine stabilization because of the tight relationship between sternum and vertebrae in the thoracic cage. There is no unanimity in literature for surgical treatment of manubriosternal dislocations, although plate fixation is generally considered a safe and effective treatment option.

Outcomes after hybrid minimally invasive treatment of Boerhaave syndrome: a single-institution experience.

BACKGROUND: Spontaneous esophageal perforation or Boerhaave syndrome is a life-threatening emergency, associated with significant morbidity and mortality. In this retrospective series we describe our single-center experience with a hybrid minimally invasive treatment approach for the treatment of Boerhaave syndrome. METHODS: Clinical data of all patients who presented with spontaneous esophageal rupture between January 2009 and December 2019 were analyzed. All patients underwent esophageal endoscopic stenting to seal the perforation and debridement of the contaminated mediastinal and pleural cavity through video-assisted thoracoscopic surgery (VATS). Primary outcome measure was defined as in-hospital death and 30-day mortality. RESULTS: Twelve patients were included with a median age of 63 years (interquartile range [IQR] 51-74 years) of whom 58% (n = 7) were male. The median Pittsburg perforation severity score was 6.5 (IQR 6-9). Endoscopic reintervention was required in 8 patients (67%), primarily due to stent dislocation. In addition, 5 patients (42%) required re-VATS due to empyema formation. Thirty-day mortality and in-hospital mortality were respectively 17% (n = 2) and 25% (n = 3). CONCLUSION: Endoscopic stenting in combination with thoracoscopic debridement is an effective and safe minimally invasive hybrid approach for the treatment of Boerhaave syndrome. This is depicted by the relatively low mortality rates, even among patients with high perforation severity scores. The relatively low mortality rates may be attributed to the combined approach of rapidly sealing the defect and decontamination of the thorax. Future studies should aim to corroborate this evidence which is limited by its sample size and retrospective nature.

Influence of the sentinel node outcome analysed by one-step nucleic acid amplification on the risk for postmastectomy radiation therapy and the scheduling of immediate breast reconstruction.

BACKGROUND: In patients with cT1-T3N0 breast cancer, postmastectomy radiation therapy (PMRT) is considered a contraindication for immediate breast reconstruction (IBR) due to a high risk of complications. The sentinel node biopsy (SNB) is an important determinant for PMRT. In this study, we evaluated the impact of SNB outcome on the planning of IBR after mastectomy. METHODS: Data of patients undergoing mastectomy and SNB in Zuyderland Medical Centre between 2016 and 2019 were retrospectively analysed. Perioperative factors influencing the planning of IBR and SNB results assessed by the intraoperative one-step nucleic acid amplification (OSNA) were registered. RESULTS: Of 397 patients, 169 opted for IBR. One hundred and seven IBRs were performed: 101 tissue expanders, 5 deep inferior epigastric perforator flaps and 1 latissimus dorsi flap.  Eighteen patients (18/107) had macrometastases in the SNB, in six of them IBR was cancelled due to the indication for PMRT (33%). In the other 12 patients IBR was executed as planned.  A delayed reconstruction was performed in 59 patients. CONCLUSION: In breast cancer patients undergoing mastectomy with macrometastases in the SNB, IBR was postponed in 33% due to risk on PMRT. To predict this risk, we advise to acknowledge the SNB outcome by using OSNA before proceeding to IBR.

Three-Dimensional Imaging of the Chest Wall: A Comparison Between Three Different Imaging Systems.

BACKGROUND: Three-dimensional (3D) imaging is being used progressively to create models of patients with anterior chest wall deformities. Resulting models are used for clinical decision-making, surgical planning, and analysis. However, given the broad range of 3D imaging systems available and the fact that planning and analysis techniques are often only validated for a single system, it is important to analyze potential intrasystem and intersystem differences. The objective of this study was to investigate the accuracy and reproducibility of three commercially available 3D imaging systems that are used to obtain images of the anterior chest wall. METHODS: Among 15 healthy volunteers, 3D images of the anterior chest wall were acquired twice per imaging device. Reproducibility was determined by comparison of consecutive images acquired per device while the true accuracy was calculated by comparison of 3D image derived and calipered anthropometric measurements. A maximum difference of 1.00 mm. was considered clinically acceptable. RESULTS: All devices demonstrated statistically comparable (P = 0.21) reproducibility with a mean absolute difference of 0.59 mm. (SD: 1.05), 0.54 mm. (SD: 2.08), and 0.48 mm. (SD: 0.60) for the 3dMD, EinScan Pro 2X Plus, and Artec Leo, respectively. The true accuracy was, respectively, 0.89 mm. (SD: 0.66), 1.27 mm. (SD: 0.94), and 0.81 mm. (SD: 0.71) for the 3dMD, EinScan, and Artec device and did not statistically differ (P = 0.085). CONCLUSIONS: Three-dimensional imaging of the anterior chest wall utilizing the 3dMD and Artec Leo is feasible with comparable reproducibility and accuracy, whereas the EinScan Pro 2X Plus is reproducible but not clinically accurate.

A single-center, randomized, non-inferiority study evaluating seroma formation after mastectomy combined with flap fixation with or without suction drainage: protocol for the Seroma reduction and drAin fRee mAstectomy (SARA) trial.

BACKGROUND: Seroma formation is a common complication after breast cancer surgery and can lead to delayed wound healing, infection, patient discomfort and repeated visits to the outpatient clinic. Mastectomy combined with flap fixation is becoming standard practice and is currently combined with closed-suction drainage. There is evidence showing that closed-suction drainage may be insufficient in preventing seroma formation. There is reasonable doubt whether there is still place for closed-suction drainage after mastectomy when flap fixation is performed. We hypothesize that mastectomy combined with flap fixation and closed suction drainage does not cause a significant lower incidence of seroma aspirations, when compared to mastectomy and flap fixation alone. Furthermore, we expect that patients without drainage will experience significantly less discomfort and comparable rates of surgical site infections. METHODS: This is a randomized controlled trial in female breast cancer patients undergoing mastectomy and flap fixation using sutures with or without sentinel lymph node biopsy (SLNB). Patients will be eligible for inclusion if they are older than 18 years, have an indication for mastectomy with or without sentinel procedure. Exclusion criteria are modified radical mastectomy, direct breast reconstruction, previous history of radiation therapy of the unilateral breast, breast conserving therapy and inability to give informed consent. A total of 250 patients will be randomly allocated to one of two groups: mastectomy combined with flap fixation and closed-suction drainage or mastectomy combined with flap fixation without drainage. Follow-up will be conducted up to six months postoperatively. The primary outcome is the proportion of patients undergoing one or more seroma aspirations. Secondary outcome measures consist of the number of invasive interventions, surgical site infection, quality of life measured using the SF-12 Health Survey, cosmesis, pain and number of additional outpatient department visits. DISCUSSION: To our knowledge, no randomized controlled trial has been conducted comparing flap fixation with and without closed-suction drainage with seroma aspiration as the primary outcome. This study could result in finding evidence that supports performing mastectomy without closed-suction drainage. TRIAL REGISTRATION: This trial was approved by the medical ethical committee of Zuyderland Medical Center METC-Z on 20 March 2019 (METCZ20190023). The SARA Trial was registered at ClinicalTrials.gov as per July 2019, Identifier: NCT04035590 .

Photographic documentation and severity quantification of pectus excavatum through three-dimensional optical surface imaging.

Conventional photography is commonly used to visually document pectus excavatum and objectively assess chest wall changes over time without repeated exposure to ionising radiation, as in our centre since 2008. However, as conventional photography is labour-intensive and lacks three-dimensional (3D) information that is essential in 3D deformities like pectus excavatum, we developed a novel imaging and processing protocol based on 3D optical surface imaging. The objective of this study was to report our developed protocol to visually document pectus excavatum through 3D imaging. We also investigated the absolute agreement of the 3D image- and conventional photography-derived pectus excavatum depth to investigate whether both techniques could be used interchangeably to measure pectus excavatum depth and assess its evolution. The protocol consisted of three consecutive steps: patient positioning and instructions, data acquisition, and data processing. Three-dimensional imaging through the developed protocol was feasible for all 19 participants. The 3D image- and photography-derived pectus excavatum depth demonstrated good to excellent agreement (intraclass correlation coefficient: 0.97; 95%-confidence interval: 0.88 to 0.99; p < 0.001). In conclusion, 3D imaging through the developed protocol is a feasible and attractive alternative to document the surface geometry of pectus excavatum and can be used interchangeably with conventional photography to determine pectus severity. Clinical registration number: NCT04185870.

Flap fixation reduces seroma in patients undergoing mastectomy: a significant implication for clinical practice.

BACKGROUND: Seroma formation is a common complication following mastectomy for invasive breast cancer. Mastectomy flap fixation is achieved by reducing dead space volume using interrupted subcutaneous sutures. METHODS: All patients undergoing mastectomy due to invasive breast cancer or ductal carcinoma in situ (DCIS) were eligible for inclusion. From May 2012 to March 2013, all patients undergoing mastectomy in two hospitals were treated using flap fixation. The skin flaps were sutured on to the pectoral muscle using polyfilament absorbable sutures. The data was retrospectively analysed and compared to a historical control group that was not treated using flap fixation (May 2011 to March 2012). RESULTS: One hundred and eighty patients were included: 92 in the flap fixation group (FF) and 88 in the historical control group (HC). A total of 33/92 (35.9%) patients developed seroma in the group that underwent flap fixation; 52/88 (59.1%) patients developed seroma in the HC group (p = 0.002). Seroma aspiration was performed in 14/92 (15.2%) patients in the FF group as opposed to 38/88 (43.2%) patients in the HC group (p < 0.001). CONCLUSIONS: Flap fixation is an effective surgical technique in reducing dead space and therefore seroma formation and seroma aspirations in patients undergoing mastectomy for invasive breast cancer or DCIS.

Low-allergenic hydrolyzed egg induces oral tolerance in mice.

BACKGROUND: Egg allergy is one of the most common food allergies in children. The standard therapy for egg allergy is strict avoidance. Yet, there is considerable clinical and scientific interest in primary or secondary prevention. A major drawback of oral tolerance (OT) induction protocols, however, is the possibility of severe side effects; thus, we have formulated a hypoallergenic egg product and demonstrate its in vivo capacity to modulate the immune system in the current study. METHODS: Hydrolyzed egg (HE) was produced using a combination of moderate heat treatment and enzymatic hydrolysis. The capacity of HE to induce OT was tested in experimental models and compared to whole egg (WE). Delayed-type hypersensitivity (DTH) responses, immune markers and potential early markers of OT were analyzed. RESULTS: Allergic responses, assessed by both DTH responses upon OVA challenge and serum OVA-specific IgE and IgG1, were decreased after treatment with HE and WE compared to the control group. Additionally, feeding WE and HE significantly decreased Th2 cytokine induction and cell proliferation, induced the activation of effector CD4+ T cells and increased numbers and percentages of ICOS+CD4+CD25+Foxp3+ cells. Furthermore, DO11.10 mouse experiments showed that HE contains other peptides than the OVA323-339 peptide that are able to induce tolerance to OVA. CONCLUSIONS: Altogether, results showed that HE induces OT in mice in a dose-dependent manner. Due to its low allergenicity compared to WE, it may represent a safer alternative for OT induction in at-risk subjects or oral immunotherapy in allergic patients.

Scapula alata, a rare complication after minimally invasive repair of pectus excavatum.

A male patient in his early 30s underwent minimally invasive repair of pectus excavatum. According to standard Nuss bar procedure, a 30-degree thoracoscope was introduced through a right midaxillary 10 mm trocar in the 4th intercostal space. Two bars and five stabilisers were placed in a retromuscular position. After discharge, the patient experienced right upper back pain requiring prolonged opioid usage for three months and right scapular winging limiting functional activities. After conservative treatment with physiotherapy for 11 months, the patient still suffered from residual scapula alata with pain and muscle weakness. On suspicion of long thoracic nerve neuropraxia related to the thoracoscope placement, an electromyogram was conducted 16 months following surgery, revealing mild polyphasic potentials of the serratus anterior muscle without abnormal muscle unit action potential. After extended conservative therapy for another year, physical examination 28 months after surgery showed almost complete resolution of scapular winging.

Gastrointestinal Tolerance of Formula-Fed Infants During the Immediate Postnatal Period in Saudi Arabia: An Observational Study.

Objective. Feeding intolerance during the early postnatal period can be distressing for families. To assess this, infants (n = 150) of mothers who had previously decided to exclusively or partially formula feed were enrolled ≤24 hours after birth. Methods. Infants were fed with a single ready-to-feed, 100% partially hydrolyzed whey protein-based formula until discharge, in accordance with standard hospital practice. Parents recorded daily the presence/severity of gastrointestinal (GI) symptoms/behaviors, rated from 0 (never) to 5 (always). A validated questionnaire was completed at discharge to evaluate symptoms of GI discomfort; scores can range from 0 to ~140 (lower scores indicate fewer symptoms). Results. Mean ± SD daily scores ranged from 0.12 ± 0.40 (fussiness/irritability) to 1.26 ± 0.90 (spitting up), indicating that GI symptoms/behaviors occurred, on average, "never" or "almost never." Mean GI discomfort scores were also very low (9.9 ± 7.4). Conclusion. These results indicate that the ready-to-feed formula was very well accepted and well tolerated during this period among healthy newborns in Saudi Arabia.

Pectus excavatum and carinatum: a narrative review of epidemiology, etiopathogenesis, clinical features, and classification.

Background and Objective: A wide variety of congenital chest wall deformities that manifest in infants, children and adolescents exists, among which are pectus excavatum and pectus carinatum. Numerous studies have been conducted over the years aiming to better understand these deformities. This report provides a brief overview of what is currently known about the epidemiology, etiopathogenesis, clinical presentation, and classification of these deformities, and highlights the gaps in knowledge. Methods: A search was conducted for all the above-described domains in the PubMed and Embase databases. Key Content and Findings: A total of 147 articles were included in this narrative review. Estimation of the true incidence and prevalence of pectus excavatum and carinatum is challenging due to lacking consensus on a definition of both deformities. Nowadays, several theories for the development of pectus excavatum and carinatum have been suggested which focus on intrinsic or extrinsic pathogenic factors, with the leading hypothesis focusing on overgrowth or growth disturbance of costal cartilages. Furthermore, genetic predisposition to the deformities is likely to exist. Pectus excavatum is frequently associated with cardiopulmonary symptoms, while pectus carinatum patients mostly present with cosmetic complaints. Both deformities are classified based on the shape or severity of the deformity. However, each classification system has its limitations. Conclusions: Substantial progress has been made in the past few decades in understanding the development and symptomatology of pectus excavatum and carinatum. Current hypotheses on the etiology of the deformities should be confirmed by biomedical and genetic studies. For clinical purposes, the establishment of a clear definition and classification system for both deformities based on objective morphologic features is eagerly anticipated.

The use of intravenous indocyanine green in minimally invasive segmental lung resections: a systematic review.

Background: To identify intersegmental planes (ISPs) in video/robot-assisted thoracoscopic segmentectomies, indocyanine green (ICG) is commonly used. The aim of this systematic review is to evaluate the efficacy of intravenous ICG in the identification of ISP. Methods: A systematic search was performed. Studies evaluating patients who underwent a video/robot-assisted thoracoscopic segmentectomy using intravenous ICG were included. The primary outcome measure was the frequency and percentage of patients in whom the ISP was adequately visualized. Secondary outcomes encompassed the ICG dose, time to visualization, time to maximum ICG visualization, time to disappearance of ICG effect and adverse reactions to ICG. Results: Eighteen studies were included for systematic review, enrolling a total of 1,090 patients. Irrespective of the injected dose, intravenous ICG identified the ISP in 94% of the cases (range, 30-100%). Overall, there was a considerable amount of heterogeneity regarding the injected dose of ICG (range, 5-25 mg or 0.05-0.5 mg/kg). The mean time before first effect of ICG was visible ranged from 10 to 40 seconds. The mean total time of ICG visibility ranged from 90 to 140 seconds after a bolus injection and was 170 seconds after continuous infusion. No adverse reactions were reported. Conclusions: After administration of intravenous ICG, visualization of the ISP is successful in up to 94% of cases, even after administration of a low dose (0.05 mg/kg) of ICG. The use of intravenous ICG is safe with no reported adverse effects in the immediate peri-operative period.

Impact of low dose superparamagnetic iron oxide tracer for sentinel node biopsy in breast conserving treatment on susceptibility artefacts on magnetic resonance imaging and contrast enhanced mammography.

BACKGROUND: Residual particles of superparamagnetic iron oxide (SPIO) tracer, used for sentinel node biopsy, cause susceptibility artefacts on breast Magnetic Resonance Imaging (MRI). We investigated the impact of these artefacts on the imaging quality of MRI and explored whether contrast-enhanced mammography (CEM) could be an alternative in the follow-up of breast cancer patients. MATERIALS AND METHODS: Data on patients' characteristics, injection site, presence, size (mm) of artefacts on full-field digital mammography (FFDM)/CEM, MRI after 1 ml SPIO was recorded. Image quality scored by two breast radiologists using a 4-point Likert system: 0: no artefacts 1: good diagnostic quality 2: impaired but still readable 3: hampered clinical assessment. Continuous variables reported as means and standard deviations (SD), categorical variables as count and percentage. RESULTS: On FFDM/CEM, performed 13 months postoperatively, no iron SPIO particles were detected, with a Likert score of 0. In all MRI (100%) images, executed at 16.6 months after SPIO injection, susceptibility artefacts at the injection sites i.e., retroareolair and lateral quadrant were observed with a mean size of 41.9 ± 9.8 mm (SD) by observer 1, and 44.8 ± 12.5 mm (SD) by observer 2, independent of the injection site. Both observers scored a Likert score of 2: locally impaired on all MRI images and sequences. CONCLUSIONS: Even 1 ml SPIO tracer used for sentinel node procedure impairs the evaluation of breast MRI at the tracer injection site beyond one year of follow-up. No impairment was observed on FFDM/CEM, suggesting that CEM might be a reliable alternative to breast MRI if required.

Intercostal nerve cryoablation versus thoracic epidural analgesia for minimal invasive Nuss repair of pectus excavatum: a protocol for a randomised clinical trial (ICE trial).

INTRODUCTION: Epidural analgesia is currently considered the gold standard in postoperative pain management for the minimally invasive Nuss procedure for pectus excavatum. Alternative analgesic strategies (eg, patient-controlled analgesia and paravertebral nerve block) fail in accomplishing adequate prolonged pain management. Furthermore, the continuous use of opioids, often prescribed in addition to all pain management strategies, comes with side effects. Intercostal nerve cryoablation seems a promising novel technique. Hence, the primary objective of this study is to determine the impact of intercostal nerve cryoablation on postoperative length of hospital stay compared with standard pain management of young pectus excavatum patients treated with the minimally invasive Nuss procedure. METHODS AND ANALYSIS: This study protocol is designed for a single centre, prospective, unblinded, randomised clinical trial. Intercostal nerve cryoablation will be compared with thoracic epidural analgesia in 50 young pectus excavatum patients (ie, 12-24 years of age) treated with the minimally invasive Nuss procedure. Block randomisation, including stratification based on age (12-16 years and 17-24 years) and sex, with an allocation ratio of 1:1 will be performed.Postoperative length of hospital stay will be recorded as the primary outcome. Secondary outcomes include (1) pain intensity, (2) operative time, (3) opioid usage, (4) complications, including neuropathic pain, (5) creatine kinase activity, (6) intensive care unit admissions, (7) readmissions, (8) postoperative mobility, (9) health-related quality of life, (10) days to return to work/school, (11) number of postoperative outpatient visits and (12) hospital costs. ETHICS AND DISSEMINATION: This protocol has been approved by the local Medical Ethics Review Committee, METC Zuyderland and Zuyd University of Applied Sciences. Participation in this study will be voluntary and informed consent will be obtained. Regardless of the outcome, the results will be disseminated through a peer-reviewed international medical journal. TRIAL REGISTRATION NUMBER: NCT05731973.