Purpose
Sigmoid diverticulitis is a disease with a high socioeconomic burden, accounting for a high number of left-sided colonic resections worldwide. Modern surgical scheduling relies on accurate ...prediction of operation times to enhance patient care and optimize healthcare resources. This study aims to develop a predictive model for surgery duration in laparoscopic sigmoid resections, based on preoperative CT biometric and demographic patient data.
Methods
This retrospective single-center cohort study included 85 patients who underwent laparoscopic sigmoid resection for diverticular disease. Potentially relevant procedure-specific anatomical parameters recommended by a surgical expert were measured in preoperative CT imaging. After random split into training and test set (75% / 25%) multiclass logistic regression was performed and a Random Forest classifier was trained on CT imaging parameters, patient age, and sex in the training cohort to predict categorized surgery duration. The models were evaluated in the test cohort using established performance metrics including receiver operating characteristics area under the curve (AUROC).
Results
The Random Forest model achieved a good average AUROC of 0.78. It allowed a very good prediction of long (AUROC = 0.89; specificity 0.71; sensitivity 1.0) and short (AUROC = 0.81; specificity 0.77; sensitivity 0.56) procedures. It clearly outperformed the multiclass logistic regression model (AUROC: average = 0.33; short = 0.31; long = 0.22).
Conclusion
A Random Forest classifier trained on demographic and CT imaging biometric patient data could predict procedure duration outliers of laparoscopic sigmoid resections. Pending validation in a multicenter study, this approach could potentially improve procedure scheduling in visceral surgery and be scaled to other procedures.
Purpose
Gastrointestinal disorders frequently necessitate surgery involving intestinal resection and anastomosis formation, potentially leading to severe complications like anastomotic leakage (AL) ...which is associated with increased morbidity, mortality, and adverse oncologic outcomes. While extensive research has explored the biology of anastomotic healing, there is limited understanding of the biomechanical properties of gastrointestinal anastomoses, which was aimed to be unraveled in this study.
Methods
An
ex-vivo
model was developed for the biomechanical analysis of 32 handsewn porcine end-to-end anastomoses, using interrupted and continuous suture techniques subjected to different flow models. While multiple cameras captured different angles of the anastomosis, comprehensive data recording of pressure, time, and temperature was performed simultaneously. Special focus was laid on monitoring time, location and pressure of anastomotic leakage (LP) and bursting pressures (BP) depending on suture techniques and flow models.
Results
Significant differences in LP, BP, and time intervals were observed based on the flow model but not on the suture techniques applied. Interestingly, anastomoses at the insertion site of the mesentery exhibited significantly higher rates of leakage and bursting compared to other sections of the anastomosis.
Conclusion
The developed
ex-vivo
model facilitated comparable, reproducible, and user-independent biomechanical analyses. Assessing biomechanical properties of anastomoses offers an advantage in identifying technical weak points to refine surgical techniques, potentially reducing complications like AL. The results indicate that mesenteric insertion serves as a potential weak spot for AL, warranting further investigations and refinements in surgical techniques to optimize outcomes in this critical area of anastomotic procedures.
DNA hypermethylation is frequently found in colorectal cancer (CRC). Methylation of helicase‐like transcription factor (HLTF) and hyperplastic polyposis 1 (HPP1) are potential and carcinoembryonic ...antigen (CEA) is an established prognostic factor in serum of patients with CRC. The aim of this study was to perform a direct comparison of the prognostic roles of these markers. Methylation status of HLTF and HPP1 was examined in pretherapeutic sera of 311 patients with CRC and matched primary tissues of 54 stage IV patients using methylation‐specific quantitative PCR. CEA was determined using an immunoenzymometric assay. Methylation of HLTF and HPP1 DNA in serum significantly correlated with tumor size, stage, grade and metastatic disease. HPP1 methylation correlated with nodal status. Overall survival was shortened in case of methylation of HLTF or HPP1 or elevated levels of CEA (p < 0.0001 for all). In stage IV, patients survival was impaired if HLTF (p = 0.0005) or HPP1 (p = 0.0003) were methylated or CEA was above the median of 27 ng/ml (p = 0.002). Multivariate analysis revealed that methylation of HLTF hazard ratio (HR) 1.8, p = 0.0438, HPP1 (HR 1.6, p = 0.0495) and CEA >27 ng/ml (HR 1.7, p = 0.0317) were independent prognostic factors in stage IV. The combination of any two or all three of these factors outperformed each marker on its own. In conclusion, the presence of methylated DNA of the genes HLTF or HPP1 in serum are independent prognostic factors in metastasized CRC. Prospective validation is required to determine their usefulness in clinical routine along with the established marker CEA.
Objective
To evaluate the radiographic changes of the alveolar ridge following application of different ridge preservation techniques 6 months after tooth extraction.
Materials and Methods
Four ...treatment modalities were randomly assigned in 40 patients: β‐tricalcium‐phosphate‐particles with polylactid coating (β‐TCP), demineralized bovine bone mineral with 10% collagen covered with a collagen matrix (DBBM‐C/CM), DBBM‐C covered with an autogenous soft‐tissue graft (DBBM‐C/PG) and spontaneous healing (control). Cone‐beam computed tomography scans were performed after treatment and 6 months later.
Results
After 6 months, the vertical changes ranged between −0.6 mm (−10.2%) for control and a gain of 0.3 mm (5.6%) for DBBM‐C/PG on the lingual side, and between −2.0 mm (−20.9%) for β‐TCP and a gain of 1.2 mm (8.1%) for DBBM‐C/PG on the buccal side. The most accentuated ridge width changes were recorded 1 mm below the crest: −3.3 mm (−43.3%, C), −6.1 mm (−77.5%, β‐TCP), −1.2 mm (−17.4%, DBBM‐C/CM) and −1.4 mm (−18.1%, DBBM‐C/PG). At all three levels, DBBM‐C with either CM or PG was not significantly differing (p > 0.05), while most other differences between the groups reached statistical significance (p < 0.05).
Conclusions
Application of DBBM‐C, covered with CM or PG, resulted in less vertical and horizontal changes of the alveolar ridge as compared with controls 6 months after extraction.
Objective
The aim was to compare the clinical, aesthetic and radiological outcome of immediately placed implants in sockets with or without periapical pathology 5 years after placement.
Materials and ...methods
Twenty‐seven patients were followed 5 years after immediate implant placement (test‐group: 12 patients with periapical pathologies; control‐group: 15 patients without periapical pathology). Clinical (FMBS, FMPS, CAL, keratinized mucosa), aesthetical (length of clinical crown, Papilla index), and radiological (vertical distance implant shoulder to first bone to implant contact (IS‐BIC)) parameters were assessed. Both 95% confidence intervals, as well as results of statistical tests (one‐sample, two‐sample, paired t‐test) were provided.
Results
After 5 years the implant survival rate was 100% for all 27 implants. In the test group the width of the keratinized mucosa increased significantly over the observation period (0.8 ± 1.0 mm). Concerning aesthetic parameters at the 3‐month as well as at the 5‐year examination no statistically significant difference could be found between the two groups. In the control‐group the papilla mesial and distal to the implant increased statistically significant during the observation period by 0.5 ± 0.5 and 0.4 ± 0.6 index score points, respectively. The position of the gingival margin at the implant site and the two neighboring teeth remained stable. At the 5‐year visit IS‐BIC measured between 1.4 ± 0.5 mm (mesial, control) and 1.7 ± 0.7 mm (distal, test), no significant difference could be found between the two groups. Over the observation period no statistically significant change of IS‐BIC could be found in the test‐ as well as in the control‐group. None of the examined radiographs revealed any signs of retrograde peri‐implantitis.
Conclusion
The replacement of teeth exhibiting periapical pathologies by implants placed immediately after tooth extraction can be a successful treatment modality with no disadvantages in clinical, aesthetical and radiological parameters to immediately placed implants into healthy sockets.
Bimanual motor control declines during ageing, affecting the ability of older adults to maintain independence. An important underlying factor is cortical atrophy, particularly affecting frontal and ...parietal areas in older adults. As these regions and their interplay are highly involved in bimanual motor preparation, we investigated age-related connectivity changes between prefrontal and premotor areas of young and older adults during the preparatory phase of complex bimanual movements using high-density electroencephalography. Generative modelling showed that excitatory inter-hemispheric prefrontal to premotor coupling in older adults predicted age-group affiliation and was associated with poor motor-performance. In contrast, excitatory intra-hemispheric prefrontal to premotor coupling enabled older adults to maintain motor-performance at the cost of lower movement speed. Our results disentangle the complex interplay in the prefrontal-premotor network during movement preparation underlying reduced bimanual control and the well-known speed-accuracy trade-off seen in older adults.
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Aim
Anastomotic leakage (AL) is one of the most dreaded complications in colorectal surgery. In 2013, the International Classification of Diseases code K91.83 for AL was introduced in Germany, ...allowing nationwide analysis of AL rates and associated parameters. The aim of this population-based study was to investigate the current incidence, risk factors, mortality, clinical management, and associated costs of AL in colorectal surgery.
Methods
A data query was performed based on diagnosis-related group data of all hospital cases of inpatients undergoing colon or sphincter-preserving rectal resections between 2013 and 2018 in Germany.
Results
A total number of 690,690 inpatient cases were included in this study. AL rates were 6.7% for colon resections and 9.2% for rectal resections in 2018. Regarding the treatment of AL, the application of endoluminal vacuum therapy increased during the studied period, while rates of relaparotomy, abdominal vacuum therapy, and terminal enterostomy remained stable. AL was associated with significantly increased in-house mortality (7.11% vs. 20.11% for colon resections and 3.52% vs. 11.33% for rectal resections in 2018) and higher socioeconomic costs (mean hospital reimbursement volume per case: 14,877€ (no AL) vs. 37,521€ (AL) for colon resections and 14,602€ (no AL) vs. 30,606€ (AL) for rectal resections in 2018).
Conclusions
During the studied time period, AL rates did not decrease, and associated mortality remained at a high level. Our study provides updated population-based data on the clinical and economic burden of AL in Germany. Focused research in the field of AL is still urgently necessary to develop targeted strategies to prevent AL, improve patient care, and decrease socioeconomic costs.
Metal-catalyzed polymerization of 2,6-naphthalenedicarboxylic acid (NDCA) to form poly-2,6-naphthalenes at various surfaces is reported. Polymerizations occur via initial formal dehydrogenation of ...self-assembled diacids with subsequent decarboxylation to give polymeric bisnaphthyl-Cu species at elevated temperature as intermediate structures (<160 °C). Further temperature increase eventually leads to poly-naphthalenes via reductive elimination. It is demonstrated that the Cu(111) surface works most efficiently to conduct such polymerizations as compared to the Au(111), Ag(111), Cu(100), and Cu(110) surfaces. Poly-2,6-naphthalene with a chain length of over 50 nm is obtained by using this approach. The decarboxylative coupling of aromatic diacids is a very promising tool which further enlarges the portfolio of reactions allowing for on-surface polymerizations and novel organometallic systems preparations.
The homocoupling of alkynes at metal surfaces, which was disclosed recently, is a promising reaction for efficient construction of conjugated nanostructures at metal surfaces. However, the role of ...the metal substrate as well as the mechanistic course of this process have not been investigated. The metal surface could act cooperatively (a) for two-dimensional confinement to properly orient the organic reactant and (b) also as an active mediator in the C–C bond-forming reaction. Herein we report covalent coupling of the dimers of 1,4-diethynylbenzene at various metal surfaces. The model reaction was investigated experimentally by STM and also by theoretical DFT calculations. Detailed statistical analysis and the theoretical results strongly support the involvement of the metal surface in the C–C bond-forming process. On the basis of these investigations, a model with two possible reaction pathways is suggested to describe the process: C–C coupling via direct CH activation and C–C coupling via alkynyl activation by π-complex formation.
Anastomotic leakage (AL) after colorectal resections is a serious complication in abdominal surgery. Especially in patients with Crohn's disease (CD), devastating courses are observed. Various risk ...factors for the failure of anastomotic healing have been identified; however, whether CD itself is independently associated with anastomotic complications still remains to be validated. A retrospective analysis of a single-institution inflammatory bowel disease (IBD) database was conducted. Only patients with elective surgery and ileocolic anastomoses were included. Patients with emergency surgery, more than one anastomosis, or protective ileostomies were excluded. For the investigation of the effect of CD on AL 141, patients with CD-type L1, B1-3 were compared to 141 patients with ileocolic anastomoses for other indications. Univariate statistics and multivariate analysis with logistic regression and backward stepwise elimination were performed. CD patients had a non-significant higher percentage of AL compared to non-IBD patients (12% vs. 5%,
= 0.053); although, the two samples differed in terms of age, body mass index (BMI), Charlson comorbidity index (CCI), and other clinical variables. However, Akaike information criterion (AIC)-based stepwise logistic regression identified CD as a factor for impaired anastomotic healing (final model:
= 0.027, OR: 17.043, CI: 1.703-257.992). Additionally, a CCI ≥ 2 (
= 0.010) and abscesses (
= 0.038) increased the disease risk. The alternative point estimate for CD as a risk factor for AL based on propensity score weighting also resulted in an increased risk, albeit lower (
= 0.005, OR 7.36, CI 1.82-29.71). CD might bear a disease-specific risk for the impaired healing of ileocolic anastomoses. CD patients are prone to postoperative complications, even in absence of other risk factors, and might benefit from treatment in dedicated centers.
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