Incidence, therapy, and outcome in the management of chronic subdural hematoma in Switzerland: a population-based multicenter cohort study.

Background: Chronic subdural hematoma (cSDH) is a disease affecting mainly elderly individuals. The reported incidence ranges from 2.0/100,000 to 58 per 100,000 person-years when only considering patients who are over 70 years old, with an overall incidence of 8.2-14.0 per 100,000 persons. Due to an estimated doubling of the population above 65 years old between 2000 and 2030, cSDH will become an even more significant concern. To gain an overview of cSDH hospital admission rates, treatment, and outcome, we performed this multicenter national cohort study of patients requiring surgical treatment of cSDH. Methods: A multicenter cohort study included patients treated in 2013 in a Swiss center accredited for residency. Demographics, medical history, symptoms, and medication were recorded. Imaging at admission was evaluated, and therapy was divided into burr hole craniostomy (BHC), twist drill craniostomy (TDC), and craniotomy. Patients' outcomes were dichotomized into good (mRS, 0-3) and poor (mRS, 4-6) outcomes. A two-sided t-test for unpaired variables was performed, while a chi-square test was performed for categorical variables, and a p-value of <0.05 was considered to be statistically significant. Results: A total of 663 patients were included. The median age was 76 years, and the overall incidence rate was 8.2/100,000. With age, the incidence rate increased to 64.2/100,000 in patients aged 80-89 years. The most prevalent symptoms were gait disturbance in 362 (58.6%) of patients, headache in 286 (46.4%), and focal neurological deficits in 252 (40.7%). CSDH distribution was unilateral in 478 (72.1%) patients, while 185 presented a bilateral hematoma with no difference in the outcome. BHC was the most performed procedure for 758 (97.3%) evacuations. CSDH recurrence was noted in 104 patients (20.1%). A good outcome was seen in almost 81% of patients. Factors associated with poor outcomes were age, GCS and mRS on admission, and the occurrence of multiple deficits present at the diagnosis of the cSDH. Conclusion: As the first multicenter national cohort-based study analyzing the disease burden of cSDH, our study reveals that the hospital admission rate of cSDH was 8.2/100,000, while with age, it rose to 64.2/100,000. A good outcome was seen in 81% of patients, who maintained the same quality of life as before the surgery. However, the mortality rate was 4%.

The impact of reduced operating room capacity on the time delay of urgent surgical care for neurosurgical patients during the COVID-19 pandemic.

Background: The COVID-19 pandemic raised major challenges to the management of patient flows and medical staff resource allocation. To prevent the collapse of medical facilities, elective diagnostic and surgical procedures were drastically reduced, canceled or rescheduled. Methods: We recorded all in-hospital treated patients and outpatient clinics visits of our neurosurgical department from March 2017 to February 2021. Changes of OR capacity, in-hospital neurosurgical treatments and outpatient clinics visits during the pandemic episode was compared on a monthly bases to the previous years. Results: A total of 3'214 data points from in-house treated patients and 11'400 outpatient clinics visits were collected. The ratio of elective (73.5% ± 1.5) to emergency surgeries (26.5% ± 1.5) remained unchanged from 2017 to 2021. Significantly less neurosurgical interventions were performed in April 2020 (-42%), significantly more in July 2020 (+36%). Number of outpatient clinics visits remained in the expected monthly range (mean n = 211 ± 67). Total OR capacity was reduced to 30% in April 2020 and 55% in January 2021. No significant delay of urgent surgical treatments was detected during restricted (<85%) OR capacity. On average, the delay of rescheduled consultations was 58 days (range 3 - 183 days), three (6.5%) were referred as emergencies. Conclusions: Dynamic monitoring and adjustment of resources is essential to maintain surgical care. The sharp restrictions of surgical activities resulted in significant fluctuations and 5% decrease of treated neurosurgical patients during the COVID-19 pandemic. However, urgent neurosurgical care was assured without significant time delay during periods of reduced OR capacity.

Eponyms of Cranial Neurosurgical Instruments: An International Collaboration to Optimize the Field of Neurosurgery.

The basic set of a cranial instrument tray is filled with eponyms of surgical instruments named after surgeons and physicians from all corners of the medical world. These include pioneers like Castroviejo, Doyen, Frazier, Gigli, Mayfield, Raney, Weitlaner, and Yasargil. These innovators have always strived to enhance and simplify procedures, ultimately shaping the way we perform surgery today. It was a process, which took several generations of surgeons and trials of instruments before its current form could be established. In this paper, the authors provide background information through a historical perspective on the pioneering surgeons and physicians, after whom the instruments were named. Data were collected by searching PubMed, Google Scholar/Books, Google, and the HathiTrust Digital Library. Additional information was obtained via personal contact with American and European medical institutions, libraries, museums, as well as with the surgeons' family members and their perspective foundations. Remembering the life stories of the inventors behind commonly used eponyms in the operating theater reminds us of the long history of even the most rudimentary neurosurgical tool. This unrelenting strive for perfection reminds us, as surgeons, of our duty to continuously assess and improve our surgical tools and processes for the benefit of our patients.

Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS).

BACKGROUND AND PURPOSE: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level. METHODS: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded. RESULTS: We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0-2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3-5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year. CONCLUSIONS: The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03245866.

The relation of optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in pediatric neurosurgery practice - Part I: Correlations, age-dependency and cut-off values.

PURPOSE: It is assumed that the width of the optic nerve sheath diameter (ONSD) is dependent on intracranial pressure (ICP) and pulsatility and thus constitutes a non-invasively accessible "window" for qualitative assessment of ICP. Data on the correlation to invasively measured ICP in children are scarce and have often been obtained from sedated patients in intensive care unit (ICU) or intraoperatively. We report on a mixed cohort of pediatric neurosurgical patients, ICP and ONSD measurements were available from both sedated and awake children, only a minority from ICU patients. METHODS: Seventy-two children were investigated. Ultrasound ONSD determination was performed immediately prior to invasive ICP measurement and the mean binocular ONSD was compared with ICP. The investigations were performed in children awake, sedated, or under general anesthesia. RESULTS: In the entire patient cohort, the correlation between ONSD and ICP was good (r = 0.52, p < 0.01). Children > 1 year revealed a better correlation (r = 0.63; p < 0.01) and those ≤ 1 year did worse (r = 0.21). Infants with open fontanelle had no correlation. In the entire cohort, the best ONSD cut-off value for detecting ICP ≥ 15 and ≥ 20 mmHg was 5.28 and 5.57 mm (OR 22.5 and 7.2, AUC 0.782 and 0.733). CONCLUSION: Transorbital ultrasound measurement of ONSD is a reliable non-invasive technique to assess increased ICP in children in every clinical situation; however, the impact of age and fontanelle status needs to be considered. ONSD thresholds enable qualitative first orientation regarding ICP categories with a very satisfying diagnostic accuracy.

The relation of optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in pediatric neurosurgery practice - Part II: Influence of wakefulness, method of ICP measurement, intra-individual ONSD-ICP correlation and changes after therapy.

PURPOSE: Previous studies correlating ultrasound (US)-based optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in children were performed under general anesthesia. To apply ONSD in daily clinical routine, it is necessary to investigate patients awake. It is furthermore essential for ICP-assessment with ONSD to know if ONSD-ICP correlation varies within individuals. In this study, we report on the influence of wakefulness, method of ICP measurement, intraindividual correlations, and dynamic changes of ONSD and ICP after ICP decreasing therapy. METHODS: The overall study included 72 children with a median age of 5.2 years. US ONSD determination was performed immediately prior to invasive ICP measurement, and the mean binocular ONSD was compared to ICP. In 10 children, a minimum of 3 ONSD/ICP measurements were performed to investigate a correlation within subjects. In 30 children, measurements were performed before and after therapy. RESULTS: Twenty-eight children were investigated awake with an excellent correlation of ONSD and ICP (r = 0.802, p < 0.01). In 10 children, at least three simultaneous ONSD and ICP measurements were performed. The intraindividual correlations were excellent (r = 0.795-1.0) however with strongly differing individual regression curves. The overall correlation within subjects was strong (r = 0.78, p < 0.01). After ICP decreasing therapy, all ONSD values decreased significantly (p < 0.01); however, there was no correlation between ∆ICP and ∆ONSD. CONCLUSION: Awake investigation does not impair the correlation between ONSD and ICP. Even if there is a good overall ONSD-ICP correlation, every individual has its own distinctive and precise correlation line. The relationship between ONSD and ICP is furthermore not uniform between individuals. Strong ICP decreases can lead to smaller ONSD changes and vice versa. This should be kept in mind when using this technique in the clinical daily routine.

Nimodipine-Induced Blood Pressure Changes Can Predict Delayed Cerebral Ischemia.

Background: Early diagnosis of delayed cerebral ischemia (DCI) in patients after aneurysmal subarachnoid hemorrhage (aSAH) still poses a leading problem in neurointensive care. The aim of this study was to analyze the effect of oral Nimodipine administration on systemic blood pressure in patients with evolving DCI compared to patients without DCI. Methods: Systolic (SBP), mean (MAP), and diastolic (DBP) blood pressures were analyzed at the time of Nimodipine administration and additionally 30, 60, and 120 min thereafter on days 1, 3, and 5 after aSAH. Additionally, the 24 h period preceding DCI and in patients without DCI day 10 after aSAH were analyzed. Statistical analysis was performed for SBP, MAP and DBP at time of Nimodipine administration and for the maximal drop in blood pressure after Nimodipine administration. Results: Thirty patients with aSAH were retrospectively analyzed with 17 patients developing DCI ("DCI") and 13 patients who did not ("Non-DCI"). DCI patients showed a more pronounced rise in MAP and DBP over the examined time period as well as a higher decrease in SBP following Nimodipine administration. A fall of 18 mmHg in SBP after Nimodipine administration showed a sensitivity of 82.4% and specificity of 92.3% for occurrence of DCI. Conclusion: An increase of MAP and DBP after aSAH and a heightened sensitivity to Nimodipine administrations may serve as additional biomarkers for early detection of evolving DCI.

Impact of Aneurysm Multiplicity on Treatment and Outcome After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: One-third of patients with aneurysmal subarachnoid hemorrhage (aSAH) have multiple intracranial aneurysms (MIA). OBJECTIVE: To determine the predictors of outcome in aSAH patients with MIA compared to aSAH patients with a single intracranial aneurysm (SIA). METHODS: The Swiss Study of Subarachnoid Hemorrhage dataset 2009-2014 was used to evaluate outcome in aSAH patients with MIA compared to patients with SIA with the aid of descriptive and multivariate regression analysis. The primary endpoints of this cohort study were presence of new stroke on computed tomography (CT) after aneurysm treatment, and presence of stroke on CT prior to discharge. The secondary endpoints were the clinical and the functional status, and the overall mortality at discharge and at 1 yr. RESULTS: Among 1689 consecutive patients, 467 had MIA (prevalence: 26.4%). The incidence of stroke was higher in the MIA than in the SIA group, both after aneurysm treatment (19.3% vs 15.1%) and at discharge (24% vs 21.4%). However, the 95% confidence interval (CI) for the corresponding odds ratio (OR) in our multivariate model included 1, indicating that the detected trends did not reach statistical significance. As for the secondary endpoints, aneurysm multiplicity was found to be an independent, statistically significant predictor for occurrence of a new focal neurological deficit between admission and discharge (OR 1.40, 95% CI 1.08-1.81). Yet, the MIA and SIA groups did not differ in terms of either functional outcome or overall survival. CONCLUSION: aSAH patients with MIA have a higher short-term morbidity than patients with SIA. This excess morbidity does not worsen the functional outcome or lower overall survival.

Repetitive Computed Tomography Perfusion for Detection of Cerebral Vasospasm-Related Hypoperfusion in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Delayed cerebral infarction after aneurysmal subarachnoid hemorrhage (aSAH) still remains the leading cause of disability in patients that survive the initial ictus. It has been shown that computed tomography perfusion (CTP) imaging can detect hypoperfused brain areas. The aim of this study was to evaluate if a single acute CTP examination at time of neurologic deterioration is sufficient or if an additional baseline CTP increases diagnostic accuracy. METHODS: Retrospective analysis of acute and baseline (within 24 hours after aneurysm treatment) CTP examinations of patients with neurologic deterioration because of vasospasm-related hypoperfusion. Patients without clinical deterioration during the vasospasm period served as control subjects. The following CTP parameters were analyzed for predefined brain regions: time to drain (TTD), mean transit time, time to peak, cerebral blood flow, and volume. RESULTS: Thirty-three patients with and 23 without neurologic deterioration were included. Baseline CTP examination did not ameliorate diagnostic accuracy of the acute CTP examination in symptomatic patients. The same was true for interhemispheric comparison of perfusion parameters of the acute examination. The CTP parameter with the highest diagnostic yield was TTD of the symptomatic brain region (threshold value, 4.7 seconds; sensitivity, 97%; specificity, 96%). CONCLUSIONS: Acute CTP examination in case of suspected vasospasm-induced neurologic deterioration after aSAH has the highest diagnostic accuracy to detect misery perfusion. Additional baseline CTP is not needed. The most sensitive parameter to detect critically perfused brain areas is TTD.

Marriage and Partnership Integrity After Aneurysmal Subarachnoid Hemorrhage: Small Alterations in Neurologic Status Matter Most.

OBJECTIVE: Common sequelae of subarachnoid hemorrhage (SAH) include somatic and/or cognitive impairment. This can cause emotional stress, social tensions, and difficulties in relationships. To test our hypothesis that more severe somatic and cognitive impairments increased the likelihood of disruption of a relationship after SAH, we assessed the integrity of marriage or partnership status in a well-evaluated subset of SAH patients. METHODS: Our sample comprised 50 SAH patients who were discharged to a neurologic, in-house rehabilitation center between 2005 and 2010. Deficits on admission to the rehabilitation center were divided into 18 categories and grouped into minor and major somatic deficits, as well as cognitive deficits. Clinical outcome scores, marital/partnership status, and duration of partnership before ictus were recorded. A follow-up questionnaire after 4.3 (2012) and 8.8 (2017) years was used to assess changes in marital/partnership status. Possible predictor parameters were estimated and included in a stepdown regression analysis. RESULTS: In 2012, after a mean follow-up of 4.3 years, 8 of the 50 SAH patients were divorced or separated, whereas after 8.8 years only 1 additional relationship had ended. In our regression model analysis, a "short duration of relationship" before SAH and the presence of a "few minor somatic deficits" were associated with a higher likelihood of divorce or separation in the near future and remained unchanged at long-term follow-up. CONCLUSION: Contrary to our hypothesis, neither the presence of severe somatic or cognitive deficits nor clinical evaluation scores reliably predicted divorce or separation after SAH.

The Barrow Neurological Institute Grading Scale as a Predictor for Delayed Cerebral Ischemia and Outcome After Aneurysmal Subarachnoid Hemorrhage: Data From a Nationwide Patient Registry (Swiss SOS).

BACKGROUND: The Barrow Neurological Institute (BNI) scale is a novel quantitative scale measuring maximal subarachnoid hemorrhage (SAH) thickness to predict delayed cerebral ischemia (DCI). This scale could replace the Fisher score, which was traditionally used for DCI prediction. OBJECTIVE: To validate the BNI scale. METHODS: All patient data were obtained from the prospective aneurysmal SAH multicenter registry. In 1321 patients, demographic data, BNI scale, DCI, and modified Rankin Scale (mRS) score up to the 1-yr follow-up (1FU) were available for descriptive and univariate statistics. Outcome was dichotomized in favorable (mRS 0-2) and unfavorable (mRS 3-6). Odds ratios (OR) for DCI of Fisher 3 patients (n = 1115, 84%) compared to a control cohort of Fisher grade 1, 2, and 4 patients (n = 206, 16%) were calculated for each BNI grade separately. RESULTS: Overall, 409 patients (31%) developed DCI with a high DCI rate in the Fisher 3 cohort (34%). With regard to the BNI scale, DCI rates went up progressively from 26% (BNI 2) to 38% (BNI 5) and corresponding OR for DCI increased from 1.9 (1.0-3.5, 95% confidence interval) to 3.4 (2.1-5.3), respectively. BNI grade 5 patients had high rates of unfavorable outcome with 75% at discharge and 58% at 1FU. Likelihood for unfavorable outcome was high in BNI grade 5 patients with OR 5.9 (3.9-8.9) at discharge and OR 6.6 (4.1-10.5) at 1FU. CONCLUSION: This multicenter external validation analysis confirms that patients with a higher BNI grade show a significantly higher risk for DCI; high BNI grade was a predictor for unfavorable outcome at discharge and 1FU.

Predictors of Occurrence and Anatomic Distribution of Multiple Aneurysms in Patients with Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: The literature on multiple intracranial aneurysms (MIA) in patients with aneurysmal subarachnoid hemorrhage (aSAH) focuses largely on risk factor analysis and consists essentially of retrospective cohort studies of limited sample size, or studies in populations outside Europe and North America. The purpose of this cohort study was to identify predictors for aneurysm multiplicity and to investigate the anatomic distribution of MIA in a representative Western cohort of patients with aSAH. METHODS: The Swiss Study of Subarachnoid Hemorrhage (SOS) database includes anonymized data from all tertiary neurovascular facilities in Switzerland. The dataset for 2009-2014 was used to compare characteristics of patients with aSAH and MIA and those with a single intracranial aneurysm (SIA) by means of descriptive and multivariate regression analysis. RESULTS: Among 1689 unselected patients with aSAH, 467 had MIA (prevalence, 27.6%). The location of the ruptured index aneurysm was correlated with the probability of finding bystander aneurysms and predicted their likely anatomic distribution. Patients with a ruptured basilar artery aneurysm (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.30-3.44) or a ruptured middle cerebral artery aneurysm (OR, 1.86; 95% CI, 1.35-2.55) were at the greatest risk for having MIA. Larger size of the index aneurysm (OR per 1 mm, 1.03; 95% CI, 1.01-1.06) was also positively correlated with aneurysm multiplicity. Males were less likely than females to have MIA (OR, 0.79; 95% CI, 0.61-1.01). CONCLUSIONS: In patients with aSAH, the location of the ruptured index aneurysm is correlated with the probability of finding bystander aneurysms, and is predictive of the sites at which bystander aneurysms are most likely to be found.

Computed tomography angiography spot sign predicts intraprocedural aneurysm rupture in subarachnoid hemorrhage.

INTRODUCTION: To analyze whether the computed tomography angiography (CTA) spot sign predicts the intraprocedural rupture rate and outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: From a prospective nationwide multicenter registry database, 1023 patients with aneurysmal subarachnoid hemorrhage (aSAH) were analyzed retrospectively. Descriptive statistics and logistic regression analysis were used to compare spot sign-positive and -negative patients with aneurysmal intracerebral hemorrhage (aICH) for baseline characteristics, aneurysmal and ICH imaging characteristics, treatment and admission status as well as outcome at discharge and 1-year follow-up (1YFU) using the modified Rankin Scale (mRS). RESULTS: A total of 218 out of 1023 aSAH patients (21%) presented with aICH including 23/218 (11%) patients with spot sign. Baseline characteristics were comparable between spot sign-positive and -negative patients. There was a higher clip-to-coil ratio in patients with than without aICH (both spot sign positive and negative). Median aICH volume was significantly higher in the spot sign-positive group (50 ml, 13-223 ml) than in the spot sign-negative group (18 ml, 1-416; p < 0.0001). Patients with a spot sign-positive aICH thus were three times as likely as those with spot sign-negative aICH to show an intraoperative aneurysm rupture [odds ratio (OR) 3.04, 95% confidence interval (CI) 1.04-8.92, p = 0.046]. Spot sign-positive aICH patients showed a significantly worse mRS at discharge (p = 0.039) than patients with spot sign-negative aICH (median mRS 5 vs. 4). Logistic regression analysis showed that the spot sign was an aICH volume-dependent predictor for outcome. Both spot sign-positive and -negative aICH patients showed comparable rates of hospital death, death at 1YFU and mRS at 1YFU. CONCLUSION: In this multicenter data analysis, patients with spot sign-positive aICH showed higher aICH volumes and a higher rate of intraprocedural aneurysm rupture, but comparable long-term outcome to spot sign-negative aICH patients.

Nanoshell assisted laser soldering of vascular tissue.

BACKGROUND AND OBJECTIVES: Laser tissue soldering (LTS) is a promising technique for tissue fusion but is limited by the lack of reproducibility particularly when the amount of indocyanine green (ICG) applied as energy absorber cannot be controlled during the soldering procedure. Nanotechnology enables the control over the quantitative binding of the ICG. The aim of this study was to establish a highly reproducible and strong tissue fusion using ICG packed nanoshells. By including the chromophore in the soldering scaffold, dilution of the energy absorber during the soldering procedure is prevented. The feasibility of this novel nanoshell soldering technique was studied by assessing the local heating of the area and tensile strength of the resulting fused tissue. STUDY DESIGN/MATERIALS AND METHODS: Nanoshells with a diameter of 250-270 nm were loaded with ICG and included in a porous polycaprolactone (PCL) scaffold doped with albumin solder. The nanoshell scaffold was used in a flexible, semi-dry formulation suitable for surgical use. Heat development, tensile strength as well as tissue damage were assessed. RESULTS: Rabbit aortic arteries were successfully soldered using an ICG packed nanoshell scaffold. Tensile strengths of these nanoshell soldered anastomoses were found to be 734 ± 327 mN (median = 640 mN). Thermal damage was restricted to the adventitia at the irradiated area. In addition, absorber dilution was prevented during the soldering procedure resulting in significantly lower variance in maximum temperature (P = 0.03) compared to the classical liquid ICG soldering technique. CONCLUSION: Using nanoshells, controlled amounts of chromophore could successfully be bound into the polymer scaffold. Diode laser soldering of vascular tissue using ICG-nanoshell scaffolds leads to strong and reproducible tissue fusion. With optimally chosen settings of irradiation time, nanoshells coating and scaffold properties, our improved LTS procedure demonstrates the potential for a clinically applicable anastomosis technique.

Tissue fusion, a new opportunity for sutureless bypass surgery.

Microsurgical suturing is the standard for cerebral bypass surgery, a technique where temporary occlusion is usually necessary. Non-occlusive techniques such as excimer laser-assisted non-occlusive anastomosis (ELANA) have certainly widened the spectrum of treatment of complex cerebrovascular situations, such as giant cerebral aneurysms, that were otherwise non-treatable. Nevertheless, the reduction of surgical risks while widening the spectrum of indications, such as a prophylactic cerebral bypass, is still a main aim, that we would like to pursue with our sutureless tissue fusion research. The primary concern in sutureless tissue fusion- and especially in tissue fusion of cerebral vessels- is the lack of reproducibility, often caused by variations in the thermal damage of the vessel. This has prevented this novel fusion technique from being applicable in daily surgical use. In this overview, we present three ways to further improve the laser tissue soldering technique.In the first section entitled "Laser Tissue Soldering Using a Biodegradable Polymer," a porous polymer scaffold doped with albumin (BSA) and indocyanine green (ICG) is presented, leading to strong and reproducible tensile strengths in tissue soldering. Histologies and future developments are discussed.In the section "Numerical Simulation for Improvement of Laser Tissue Soldering," a powerful theoretical simulation model is used to calculate temperature distribution during soldering. The goal of this research is to have a tool in hand that allows us to determine laser irradiation parameters that guarantee strong vessel fusion without thermally damaging the inner structures such as the intima and endothelium.In a third section, "Nanoparticles in Laser Tissue Soldering," we demonstrate that nanoparticles can be used to produce a stable and well-defined spatial absorption profile in the scaffold, which is an important step towards increasing the reproducibility. The risks of implanting nanoparticles into a biodegradable scaffold are discussed.Step by step, these developments in sutureless tissue fusion have improved the tensile strength and the reproducibility, and are constantly evolving towards a clinically applicable anastomosis technique.