Osseointegration of titanium implants after surface treatment with ultraviolet light or cold atmospheric plasma in vivo.

PURPOSE: To determine the histological effects of ultraviolet light and cold atmospheric plasma treatment on the osseointegration of titanium implants in vivo. MATERIALS AND METHODS: Six juvenile pigs were divided into three groups of two animals each. A total of 54 titanium implants were placed randomly in the pigs' calvarial bone (nine implants per pig). Of these, 18 implants served as untreated controls. The remaining 36 implants served as the experimental group and were treated with either ultraviolet light or argon plasma for 12 minutes each prior to insertion. Two pigs in each group were kept until 2, 4 and 8 weeks and then sacrificed. Resonance frequency analysis was conducted after implant placement and at the time of sacrifice. Osseointegration was evaluated using microcomputed tomography scans and histomorphometrical analysis. RESULTS: After initial loss, all implants showed a constant increase in implant stability quotient values over time without significant differences between the groups. The bone-implant contact values increased steadily for all implants over 8 weeks of healing. Surface-treated implants showed significantly higher bone-implant contact values compared to untreated implants at each time point. Bone area fraction occupancy values were almost always higher following both treatment methods; however, differences were only significant after 4 and 8 weeks for the cold atmospheric plasma group and after 4 weeks for the ultraviolet light group. CONCLUSIONS: Ultraviolet light and cold atmospheric plasma may improve histomorphometrical osseointegration of titanium implants significantly.

Comparison of functional and esthetic outcomes in digital versus analog rehabilitation of one-piece screw-retained implant crowns placed at second stage surgery.

PURPOSE: Analog and digital impressions are established procedures for restoration of single-tooth implants. In this study, single-tooth implants were restored with definitive restorations during second-stage surgery. Analog and digital workflows were compared. MATERIAL AND METHODS: Eighty single-tooth implants were examined in total. In 40 implants, an index was taken immediately after implant placement using composite resin to fabricate the final crowns (analog workflow). For the other 40 single-tooth implants, intraoral intraoperative scans were performed (digital workflow) during primary surgery. The custom-fabricated screw-retained crowns were placed during second-stage surgery. Photographs and examinations for the scores were taken at the time of the follow-up visit, 1-4 years after placement of the crowns. The number of treatment appointments required was recorded and the modified pink esthetic score (PES) was determined. Additionally, the functional implant prosthetic score (FIPS) was measured. RESULTS: The mean PES was 12.15/14 for the digital workflow and 11.95/14 for the analog workflow. The most common deficit was incomplete papillae for both workflows. Three treatment appointments were required for both workflows: (1) Scan and/or impressions making and patient consent, (2) implant placement, and (3) second-stage surgery with crown insertion. The FIPS was 9.1/10 for the digital workflow group and 9.2/10 for the analog workflow group. Common deficits presented as missing papillae as well as open approximal contacts. The FIPS was not significantly different between workflows (p = 0.679). The PES also did not show a statistically significant difference for both workflows (p = 0.654), however, the analog workflow showed better values for the papillae (p < 0.05). A significant difference was also found in the other PES values, with the digital workflow showing better results here (p < 0.05). A chronological analysis of the results of the digital technique showed that the cases treated last had significantly better values than the cases treated first. CONCLUSIONS: According to the results of this study, both workflows allowed placement of the definitive crowns on single-tooth implants during second-stage surgery. Both workflows were found to be equivalent in terms of esthetic results in this study, although the digital workflow demonstrated a learning curve.

Coronary Artery Bypass Grafting in Patients With High Risk of Bleeding.

BACKGROUND: Postoperative bleeding after cardiac surgery is associated with increased morbidity and mortality. We tested the hypothesis that patients with a preoperatively estimated high risk of severe perioperative bleeding may have impaired early outcome after on-pump versus off-pump coronary artery bypass grafting (CABG). METHOD: Data from 7,352 consecutive patients who underwent isolated CABG from January 2015 to May 2017 were included in the multicentre European Coronary Artery Bypass Grafting registry. The postoperative bleeding risk was estimated using the WILL-BLEED risk score. Of all included patients, 3,548 had an increased risk of severe perioperative bleeding (defined as a WILL-BLEED score ≥4) and were the subjects of this analysis. We compared the early outcomes between patients who underwent on-pump or off-pump CABG using a multivariate mixed model for risk-adjusted analysis. RESULTS: Off-pump surgery was performed in 721 patients (20.3%). On-pump patients received more packed red blood cell units (on-pump: 1.41 [95% confidence interval {CI} 0.99-1.86]; off-pump: 0.86 [95% CI 0.64-1.08]; p<0.001), had a longer stay in the intensive care unit (on-pump: 4.4 [95% CI 3.6-8.1] days; off-pump: 3.2 [95% CI 2.0-4.4] days; p=0.049), and a higher rate of postoperative atrial fibrillation (on-pump: 46.5% [95% CI 34.9-58.1]; off-pump: 31.3% [95% CI 21.7-40.9]; p=0.025). Furthermore, on-pump patients showed a trend towards a higher rate of postoperative stroke (on-pump: 2.4% [95% CI 0.9-4.1]; off-pump: 1.1 [95% CI 0.2-2.7]; p=0.094). CONCLUSION: Our data suggest that in patients with an increased risk of bleeding, the use of cardiopulmonary bypass is associated with higher morbidity. These patients may benefit from off-pump surgery if complete revascularisation can be ensured.

Influence of surface condition on the degradation behaviour and biocompatibility of additively manufactured WE43.

The further development of future Magnesium based biodegradable implants must consider not only the freedom of design, but also comprise implant volume reduction, as both aspects are crucial for the development of higher functionalised implants, such as plate systems or scaffold grafts in bone replacement therapy. As conventional manufacturing methods such as turning and milling are often accompanied by limitations concerning implant design and functionality, the process of laser powder bed fusion (LPBF) specifically for Magnesium alloys was recently introduced. In addition, the control of the degradation rate remains a key aspect regarding biodegradable implants. Recent studies focusing on the degradation behaviour of additively manufactured Magnesium scaffolds disclosed additional intricacies when compared to conventionally manufactured Magnesium parts, as a notably larger surface area was exposed to the immersion medium and scaffold struts degraded non-uniformly. Moreover, chemical etching as post processing technique is applied to remove sintered powder particles from the surface, altering surface chemistry. In this study, cylindrical Magnesium specimens were manufactured by LPBF and surfaces were consecutively modified by phosphoric etching and machining. Degradation behaviour and biocompatibility were then investigated, revealing that etched samples exhibited the overall lowest degradation rates, but experienced large pit formation, while the reduction of surface roughness resulted in a delay of degradation.

Liver surgery-specific complications are an independent factor influencing long-term survival following major hepatectomy.

BACKGROUND: A severity grading system for liver surgery-specific complications, given the acronym FABIB, has been standardized to increase the feasibility and comparability of academic reports in liver surgery. Whether the FABIB score is associated with long-term survival following major hepatectomy has not been previously investigated. METHODS: 297 consecutive patients who had undergone major hepatectomy between 2012 and 2019 were recruited. The postoperative complications were documented according to the FABIB system and, for comparison purposes, Clavien-Dindo classification. Their influence on 90-day mortality and long-term survival was analyzed retrospectively. RESULTS: Taking the relevant confounders into account, the FABIB score was a robust factor associated with long-term survival after major hepatectomy: patients with high FABIB scores (≥6) had a 2.415-fold higher risk of death compared to patients with low FABIB scores (≤2) (P = 0.002). In contrast to that, the Clavien-Dindo Classification (grade III + IV vs. grade I + II) was not associated with survival in our cohort (P = 0.873). CONCLUSION: Liver surgery-specific complications, measured by the FABIB system, impact long-term survival after major hepatectomy independent of relevant confounders. We propose the FABIB score as a composite endpoint for randomized controlled trials and a quality assessment tool in liver surgery.

A potential for seamless designs in diagnostic research could be identified.

BACKGROUND AND OBJECTIVE: New diagnostic tests to identify a well-established disease state must undergo a series of scientific studies from test construction to finally demonstrating a societal impact. Traditionally, these studies are performed with substantial time gaps in between, resulting in a long time period from the initial idea to roll out in clinical practice including reimbursement. Seamless designs allowing us to combine a sequence of studies in one protocol may hence accelerate this process. Currently, a systematic investigation of the potential of seamless designs in diagnostic research is lacking. METHODS: We identify major study types in diagnostic research and their basic characteristics with respect to the application of seamless designs. This information is used to identify major hurdles and opportunities for seamless designs. RESULTS: The following major study types were identified: Variable construction studies, cut point finding studies, variable value studies, single-arm accuracy studies, comparative accuracy studies, change-in-management studies, observational discordant pair studies, randomized discordant pair studies, and randomized diagnostic studies. The following characteristics were identified: Type of recruitment (case-control vs. population-based), application of a reference standard, inclusion of a comparator, paired or unpaired application of a comparator, assessment of patient-relevant outcomes, and possibility for blinding of test results. Two basic hurdles could be identified: 1) Accuracy studies are hard to combine with postaccuracy studies in a seamless design for the following reasons. First, because the former are required to justify the latter and application of a reference test in outcome studies may be a threat to the integrity of the study. 2) Randomized diagnostic studies are probably best placed as singular studies at the end of the process, as all other questions should be clarified before performing such a study. However, otherwise there is a substantial potential for seamless designs. All steps from the construction to the comparison with the comparator can be combined in one protocol. This may include a switch from case-control to population-based recruitment as well as a switch from a single-arm study to a comparative accuracy study. In addition, change-in-management studies can be combined with an outcome study in discordant pairs. CONCLUSION: There is a potential for seamless designs in diagnostic research. It is wise to have the whole sequence of necessary studies in mind and to plan a full programme than rather individual studies one by one.

Rational surgical neck management in total laryngectomy for advanced stage laryngeal squamous cell carcinomas.

PURPOSE: Controversies exist in regard to surgical neck management in total laryngectomies (TL). International guidelines do not sufficiently discriminate neck sides and sublevels, or minimal neck-dissection nodal yield (NY). METHODS: Thirty-seven consecutive primary TL cases from 2009 to 2019 were retrospectively analyzed in terms of local tumor growth using a previously established imaging scheme, metastatic neck involvement, and NY impact on survival. RESULTS: There was no case of level IIB involvement on any side. For type A and B tumor midline involvement, no positive contralateral lymph nodes were found. Craniocaudal tumor extension correlated with contralateral neck involvement (OR: 1.098, p = 0.0493) and showed increased involvement when extending 33 mm (p = 0.0134). Using a bilateral NY of ≥ 24 for 5-year overall survival (OS) and ≥ 26 for 5-year disease-free survival (DFS) gave significantly increased rate advantages of 64 and 56%, respectively (both p < 0.0001). CONCLUSIONS: This work sheds light on regional metastatic distribution pattern and its influence on TL cases. An NY of n ≥ 26 can be considered a desirable benchmark for bilateral selective neck dissections as it leads to improved OS and DFS. Therefore, an omission of distinct neck levels cannot be promoted at this time.

Is It Feasible to Standardize a Composite Postoperative Complication Reporting System for Liver Resection?

BACKGROUND: Although the Clavien-Dindo classification is well established in many fields of surgery, a conclusive severity grading system for liver surgery-specific complications has not yet been standardized. Post-hepatectomy liver Failure, Ascites, Bile leakage, Infection, and Bleeding were found to be the five most important components in an international survey. A score system with FABIB as the acronym was proposed by the authors to increase the feasibility of routine use. METHODS: The definition and grading of three components ("liver failure," "bile leakage," and "bleeding") were adopted from the International Study Group for Liver Surgery. The definition and grading for "ascites" as well as "infection" were proposed by the authors. The postoperative complications were documented prospectively. The data from 2012 to 2016 were reviewed and the correlations to other clinical parameters were analyzed retrospectively. RESULTS: Five hundred one consecutive liver resections were assessed. Two hundred twenty-four (44.7%) patients had at least one postoperative complication of the FABIB system. The FABIB score was found to correlate with the operation complexity (major vs minor liver resection, with or without biliodigestive anastomosis), underlying liver disease (normal liver parenchyma vs fibrosis vs cirrhotic liver), 90-day mortality (statistically significantly different within three predefined categories), and the length of hospital stay (the mean value increases proportionately to FABIB score). CONCLUSION: Using the FABIB reporting system, the five main complications after liver surgery can be documented in a standardized manner. Its clinical relevance might increase the feasibility and comparability of studies or trials in liver surgery.