Fiber-Optic Temperature and Pressure Sensors Applied to Radiofrequency Thermal Ablation in Liver Phantom: Methodology and Experimental Measurements

Radiofrequency thermal ablation (RFA) is a procedure aimed at interventional cancer care and is applied to the treatment of small- and midsize tumors in lung, kidney, liver, and other tissues. RFA generates a selective high-temperature field in the tissue; temperature values and their persistency are directly related to the mortality rate of tumor cells. Temperature measurement in up to 3–5 points, using electrical thermocouples, belongs to the present clinical practice of RFA and is the foundation of a physical model of the ablation process. Fiber-optic sensors allow extending the detection of biophysical parameters to a vast plurality of sensing points, using miniature and noninvasive technologies that do not alter the RFA pattern. This work addresses the methodology for optical measurement of temperature distribution and pressure using four different fiber-optic technologies: fiber Bragg gratings (FBGs), linearly chirped FBGs (LCFBGs), Rayleigh scattering-based distributed temperature system (DTS), and extrinsic Fabry-Perot interferometry (EFPI). For each instrument, methodology for ex vivo sensing, as well as experimental results, is reported, leading to the application of fiber-optic technologies in vivo. The possibility of using a fiber-optic sensor network, in conjunction with a suitable ablation device, can enable smart ablation procedure whereas ablation parameters are dynamically changed

Anatomical study of the pre-segmental and segmental arteries of the kidney and their impact in the nephronsparing surgery

Clamping of the main renal artery (RA) is still regarded as a commonly used technique to decrease haemorrhage in partial nephrectomy, but it causes warm ischaemic injury. The aim of this study was to describe the pattern of pre-segmental and segmental branches of the RA. To obtain vascular corrosions casts, twenty kidneys were injected with acrylic resins and underwent to computed tomography examination. Analysis of images and of casts showed that the pattern of vascularisation of posterior renal segment was constant (except that in one case), presenting one segmental artery. The vascularisation of the anterior parenchyma (apical, superior, middle and inferior segments) originated directly from an anterior branch of the RA (70%) or thorough pre-segmental arteries (PSA) (30%). In 20% two middle segmental artery originated from two different PSAs. A series of vascular renal patterns have been identified, that the surgeon must know before to conduct the selective clamping, i.e. the selective clamping of segmental artery originating from a PSA could more difficult, because the surgeon can wrongly close the PSA with subsequent ischemia of the more parenchymal segments. Moreover, in case of multiple segmental arteries, originating from two PSA, the surgeon can wrongly clamp only one of them with subsequent intraoperative hemorrhage

An anatomo-radiological study of the renal segments

An increasing number of observations call the general scheme of five renal segments into question, with anatomists, radiologists and surgeons that have reported discrepancies between Graves’s scheme and morphological observations. The aims of the present study was to analyse the arterial vascular anatomy with reference to the renal segments. 15 kidneys were injected with acrylic resins to obtain vascular corrosions casts that were analyzed also with computed tomography. A mean number of 6,1 (range 4-8) avascular fissures were found, determining the presence of a mean number of 7,1 segments (range 5-9). The apical and posterior segments were in all the cases single. In the superior and middle territory there was a single segment in 6 cases (40%) and two segments in 9 cases (60%). In the inferior territory there was a single segment in 1 case (6,7%), two segments in 12 cases (80%), and three segments in 2 cases (13,3%). The renal arterial vasculature cannot be schematized according to the classical Graves classification because the majority of the evaluated cases showed a different number of segments. The presence of the fissures in the virtual vascular casts is a useful tool to identify the boundary between the vascular territories

Lipid and metabolite correlation networks specific to clinical and biochemical covariate show differences associated with sexual dimorphism in a cohort of nonagenarians

This study defines and estimates the metabolite-lipidic component association networks constructed from an array of 20 metabolites and 114 lipids identified and quantified via NMR spectroscopy in the serum of a cohort of 355 Italian nonagenarians and ultra-nonagenarian. Metabolite-lipid association networks were built for men and women and related to an array of 101 clinical and biochemical parameters, including the presence of diseases, bio-humoral parameters, familiarity diseases, drugs treatments, and risk factors. Different connectivity patterns were observed in lipids, branched chains amino acids, alanine, and ketone bodies, suggesting their association with the sex-related and sex-clinical condition-related intrinsic metabolic changes. Furthermore, our results demonstrate, using a holistic system biology approach, that the characterization of metabolic structures and their dynamic inter-connections is a promising tool to shed light on the dimorphic pathophysiological mechanisms of aging at the molecular level.</p

Brödel’s line: an anatomo-radiological study of the avascular kidney’s plane

The division in anterior and posterior branches of the renal artery implies the existence of an avascular plane, the so call Brödel’s line (1). This longitudinal zone is described along the convex renal border (2) or just posterior to the lateral aspect of the kidney (3). The aim of this study was to describe the extension of Brödel’s line with reference to the renal segments. 12 kidneys were injected with acrylic resins to obtain vascular corrosions casts that were analyzed also with computed tomography. We observed the presence of a relative avascular plane in all vascular casts, located on the posterior surface, ascribable to the Brodel’s line. In 33% of cases the line extended from the apical to the inferior segments, in the 33% of cases it extended from the superior to the inferior segments, in 33% of cases it is limited to the superior and middle segments. Since the Brödel’s line corresponds with the plane of the anterior surface of the posterior hilar calyces, the knowledge of its extension is relevant from the surgical point of view: this area permits a relatively safe access route to the pelvicalyceal system for nephrostomy insertion and incision within this plane results in significantly less blood loss than outside this plane

Clinical anatomy of the caudal pancreatic arteries and their relevance in the surgery of the splenic trauma

Splenectomy is the treatment of splenic trauma but is not exempt from intra-operative and post-operative complications. Conservative approach is preferred for paediatric population and for minor trauma. The aim of the present study was to evaluate the vascularisation of the tail of the pancreas, with particular reference to the presence of anastomosis between the pancreatic and splenic vessels, through an anatomoradiologic study performed on 9 unembalmed cadavers (age range 44-77 years). To obtain vascular corrosion casts, the splenic, the gastroduodenal and the superior mesenteric arteries were injected with acrylic and radioopaque resins and computed tomography (CT) of the specimens were acquired. The caudal pancreatic arteries (mean number ± standard deviation: 3.2 ± 2.4) were observable in all the casts, originating from the splenic artery at its distal third (70%) and from its inferior branch (30%). At CT scans analysis the mean calibre of caudal pancreatic arteries was 2.1 ± 1.1 mm. Anastomosis were found with great pancreatic artery in 20%, and with hilar splenic artery in 80%. The pattern of anastomosis between the pancreas tail and the spleen could allow the surgeon to close the splenic artery at the origin and also the short gastric and the left gastroepiploic arteries, in cases of splenic trauma, favouring the hemostasis and allowing splenic preservation at a same time

Anatomical and Radiologic study about the vascular supply of the pancreas interrelated with resective surgery

Postoperative pancreatic fistula is still regarded as a major complication. Its incidence varies greatly in different reports. The aim of the present study was to evaluate possible correlation between the incidence of postoperative complications and the vascular architecture of the pancreas. Ten specimens of pancreas, duodenum and spleen were injected to obtain vascular casts of the hepatic, splenic and superior mesenteric artery (SMA). Computed tomography angiographs of the upper abdomen of 30 patients, that undergone to pancreatoduodenectomy, and of 50 subject controls (25 female, 25 men) with a mean age of 70.2 years were analysed to investigate the depiction rate and branching of the vascular supply of the pancreas main vessels. The anterior superior pancreaticoduodenal artery (ASPD) and the posterior superior pancreaticoduodenal artery (PSPD) were visible in 95% and 98.2%. The ASPD contributes to create one or two anterior arcade in 90% and 10% respectively, the PSPD contributes to create one posterior arcade in 100%. The inferior pancreaticoduodenal stem was visible in 100% with its two branches. The inferior origin of the posterior arcade i.e. inferior anterior pancreaticoduodenal artery (IAPA) emerges from SMA in 40%, from the first jejunal artery in 60%.The dorsal pancreatic artery (DPA) was visible in 45%, coming from the splenic artery in 60%, from the celiac trunk in 30%, from the common hepatic artery on 10%. The transverse artery was visible in 80% coming from the SMA in 60%, from the dorsal pancreatic artery in 30% and from the anterior arcade in 10%. Preoperative understanding of the vascular anatomy of the pancreatic head is important in order to reduce frequency of complication

Transcatheter Aortic Valve Implantation (TAVI) Planning with Dual-Layer Spectral CT Using Virtual Monoenergetic Image (VMI) Reconstructions and 20 mL of Contrast Media

Transcatheter aortic valve implantation (TAVI) is a less invasive alternative to surgical implantation and its implementation is progressively increasing worldwide. We routinely perform pre-procedural aortic angiography CT to assess aortic dimensions and vascular anatomy. This study aims to evaluate the image quality of CTA for TAVI planning using dual-layer spectral CT, with virtual monoenergetic image reconstructions at 40 keV. Thirty-one patients underwent a CTA protocol with the injection of 20 mL of contrast media. Image quality was assessed by measuring the mean density in Hounsfield Units (HU), the signal-to-noise ratio, and the contrast-to-noise ratio in VMI reconstructions. Additionally, a blinded subjective analysis was conducted by two observers. The results showed significant enhancement at all sampled vascular levels with a gradual decrease in HU from proximal to distal regions. Favourable subjective ratings were given for all parameters, with greater variability in the evaluation of iliac axes. A significant negative correlation (p &lt; 0.05) was observed between BMI and CA at all vascular levels, indicating reduced contrast enhancement with increasing BMI. Spectral CT, along with reducing iodine load, allows for obtaining high-quality images without a significant increase in noise. The reduction in iodine load can have positive implications in clinical practice, improving patient safety and resource efficiency

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P &lt; .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients