Small-caliber Veins Research Articles

Tongue patch angioplasty for small-caliber vein segments directly connected to juxta-anastomotic stenosis.

This study introduces a surgical method to increase the size of small vessels in patients with juxta-anastomosis stenosis (JAS) requiring full-length dissection. The small-caliber segment that is adjacent to JAS is usually expanded using balloon angioplasty or surgically resected. After resection, if the cannulation site is sufficient, only the arterial anastomosis is moved proximally; otherwise, it is replaced with a prosthetic graft. Herein, we describe the cases of two 60- and 34-year-old men with left brachio-basilar and left radiocephalic fistulas, respectively. The first and second patients needed transposition and superficialization, respectively, both of which required full-length vessel dissection. Both patients developed JAS with a long, small-caliber segment, leaving no space for arterial needle cannulation. A tongue patch with a graft on the bottom and a native vein on the top was used to resolve the JAS and make the native vein the needle cannulation site. In our cases, this method was effective for more than 2 years without adverse events in the particular surgical area. Although this method had a complicated indication, it could help ensure a sufficiently long area of the native vein for cannulation.

Hipertensão Arterial Pulmonar com Características de Envolvimento Venoso: Um Trabalho Investigativo

Abstract Pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangiomatosis are rare types of histopathological substrates within the spectrum of pulmonary arterial hypertension (PAH) with a very poor prognosis. They are characterized by a widespread fibroproliferative process of the small caliber veins and/or capillaries with sparing of the larger veins, resulting in a pre-capillary pulmonary hypertension phenotype. Clinical presentation is unspecific and similar to other PAH etiologies. Definitive diagnosis is obtained through histological analysis, although lung biopsy is not advised due to a higher risk of complications. However, some additional findings may allow a presumptive clinical diagnosis of PVOD, particularly a history of smoking, chemotherapy drug use, exposure to organic solvents (particularly trichloroethylene), low diffusing capacity for carbon monoxide (DLCO), exercise induced desaturation, and evidence of venous congestion without left heart disease on imaging, manifested by a classical triad of ground glass opacities, septal lines, and lymphadenopathies. Lung transplant is the only effective treatment, and patients should be referred at the time of diagnosis due to the rapid progression of the disease and associated poor prognosis. We present a case of a 58-year-old man with PAH with features of venous/capillary involvement in which clinical suspicion, prompt diagnosis, and early referral for lung transplantation were determinant factors for the successful outcome.

#4047 ULTRASOUND-GUIDED RIGHT INTERNAL JUGULAR TUNNELED CATHETER INSERTION FOR HAEMODIALYSIS: PRACTICES AND OUTCOMES FROM A SINGLE CENTRE

Abstract Background and Aims Internal jugular vein tunneled catheters are important vascular access for haemodialysis (HD). In our practice, Left-sided internal jugular (LIJ) catheter insertion is performed in radiology under direct X-ray screening. Most right-side internal jugular (RIJ) catheters are inserted under ultrasound guidance in dedicated renal procedure rooms. Vascular access can become challenging with the potential for venous stenosis and thrombosis with catheter use. The aims of this study are to evaluate our practices and outcomes of non-radiologically inserted RIJ tunneled HD catheters and to investigate the predictors of procedure failure. Method 200 successive RIJ tunnel HD catheters inserted from June 2016 under ultrasound guidance at our centre were included in this analysis. Data including demographics, co-morbidities, first or higher order insertion, outcome (success or failed attempt), and immediate complications were collated from electronic patient records. Binary logistic regression analysis was conducted to investigate the predictor for failure in catheter insertion. Results Of the 200 patients, 152 (76%) were first-time insertions and 48 (24%) were second or higher-order insertions. The median age of our cohort was 58 years, with a predominance of males (68%) and white ethnicity (82%). 36.5% were diabetic, with 37.5% having a history of cardiovascular disease. Nearly 30% of patients were on an antiplatelet agent, and 8% were on anticoagulants, which were appropriately managed before line insertion. Pre-operative median haemoglobin was 93 g/dl, with clotting screen and platelet counts in the target range. There was a statistically significant difference in the success of insertion, depending on the insertion being first or subsequent (96.1% vs 81.2%; p = 0.001). The reason for failure in insertion included on-table observation of a small calibre vein on ultrasound or failure to thread wire/dilator due to possible stenosis or thromboses. All line rewire (12/48) procedures were performed successfully. Immediate complication (<1 week) was recorded in 9% of patients, predominantly tunnel bleeding (n = 7) and malposition (deep or high; n = 7) (Table 1). Second or higher-order RIJ catheter insertion showed a higher risk for failure in a multivariable binary logistic regression analysis. (OR: 6.4; CI: 2.1-20.5; P = 0.002) (Figure 1). Of the higher-order insertions, the longer duration between the first and subsequent catheters showed a higher risk for failure (OR:1.19; CI-1.04-1.4; p = 0.010). Conclusion Second or higher-order catheter insertions with a longer duration between the first and the subsequent insertion carry a significant risk of failure due to vein stenosis and thrombosis. Therefore, a careful case-to-case triaging of patients based on previous access history is warranted before listing patients for routine ultrasound-guided insertion.

Long-term efficacy and risk factors of balloon-assisted maturation for radial-cephalic arteriovenous fistula with small-caliber veins.

Balloon angioplasty maturation (BAM) is a salvage method for autologous arteriovenous fistula (AVF) maturation failure. AVF creation using small-diameter veins is considered to have poor outcomes. Therefore, this study aimed to explore the long-term patency of small-diameter veins (≤3 mm) using BAM. BAM was performed if the fistula failed to mature and function adequately to provide prescribed dialysis. Out of 61 AVFs, 22 AVFs successfully matured without further intervention (AVF group) and 39 AVFs failed to mature. Except for 1 patient who required peritoneal dialysis, the remaining 38 patients received salvage BAM, and 36 of those successful matured (BAM group). Kaplan-Meier analysis revealed no significant differences between the AVF and BAM groups in terms of primary functional patency (p = 0.503) and assisted functional patency (p = 0.499). Compared with the AVF group, the BAM group had similar assisted primary functional patency (1-year: 94.7% vs. 93.1%; 3-year: 88.0% vs. 93.1%; 5-year: 79.2% vs. 88.3%). In addition, there were no significant difference between groups in the duration of primary functional patency and assisted primary functional patency (p > 0.05). Multivariate analyses showed that vein diameter and number of BAM procedures were independent predictors of primary functional patency in the AVF group and BAM group, respectively. Patient with 1 mm increase in vein size had 0.13-fold probability of having decreased duration of patency (HR = 0.13, 95% CI: 0.02-0.99, p = 0.049), while patients who received two times of BAM procedures were 2.885 as likely to have decreased duration of primary functional patency (HR = 2.885, 95% CI: 1.09-7.63, p = 0.033) than patients who received one BAM procedure. BAM is a relatively effective salvage management option with an acceptable long-term patency rate, even for small cephalic veins.

The feasibility of small-caliber veins for autogenous arteriovenous fistula creation: A single-center retrospective study.

Autogenous arteriovenous fistula (AVF) is recommended as the first choice for hemodialysis vascular access. A small-caliber vein is one of the independent risk factors for AVF maturation and patency. However, the specific threshold is still unclear, making it difficult to accurately determine whether these vessels are suitable for AVF creation. This is a single-center retrospective study. Patients who underwent AVF creation in our medical center between January 2020 and September 2022 and satisfied the eligibility criteria were included in this retrospective study. Logistic regression analysis was performed to identify risk factors for functional maturation and additional intervention. The optimal cutoff value was determined based on the receiver operating curve (ROC) and the Youden index. Kaplan-Meier analysis was utilized in further patency rate comparisons. A total of 125 forearm AVFs were created in 121 patients with end-stage renal disease (ESRD). The mean age was 53.88 ± 15.10 years. Preoperative vascular Doppler ultrasound (DUS) was conducted and recorded in 106 cases (84.80%). The mean targeted artery and vein diameters were 2.17 ± 0.54 and 1.71 ± 0.75 mm, respectively. Small-caliber vein is the risk factor for functional maturation failure (OR = 0.256, 95%CI [0.06-0.75], p = 0.033) and additional intervention (OR = 0.306, 95% CI [0.09-0.78], p = 0.031). The optimal cutoff value is 1.35 mm (augmented) when specificity and sensitivity reach 80 and 63.7%, respectively. The AVFs with a vein diameter of more than 1.35 mm (augmented) showed higher patency rates (p < 0.01). After comprehensive DUS evaluation, intraoperative hydrodilation, postoperative active exercise and intensive DUS detection, and application of balloon-assisted maturation, if necessary, using a vein more than 1.35 mm (augmented), could achieve satisfactory functional maturation and postoperative patency in AVF formation.

Microcirculation in fractures of long bones of the lower extremity

The study objective was to investigate soft tissue microcirculation in the area of a lower limb long bone fracture. We studied fractures of the lower limb long bones from 0 to 7 days of age in 17 males and 37 females. The mean age of patients was 57.33±2.53 years. Histological examination of soft tissues from the area of the lower limb long bone fracture and at the distance from the fracture was performed. Standard hematoxylin and eosin staining was used. The thickness and diameter of arterioles, venules, and capillaries were evaluated by morphometry of the sections made. The observed pattern reflects the response of the microcirculation of the soft tissues to the mechanical impact. The relative ratio of the artery diameter to the small-caliber vein diameter was 1.01±0.13, and the artery wall thickness to the vein wall thickness was 2.03±0.28, which can be considered a natural reaction of the microcirculation blood vessels to the mechanical impact in 1-1.5 weeks after the formed fracture of the lower limb long bone.

Immediate lymphatic reconstruction for breast cancer

: Upper extremity lymphedema remains a significant source of morbidity in breast cancer patients despite significant improvements in breast cancer care. The risk of lymphedema is particularly elevated in patients requiring an axillary lymph node dissection and/or adjuvant radiation to treat their disease. Current treatment options for lymphedema, including conservative management or surgery, are limited and are often aimed at improving symptoms and quality of life rather than curing the disease. In this review we describe immediate lymphatic reconstruction, a novel surgical procedure that is done concurrent with axillary lymph node dissection in an effort to prevent the development of breast cancer-related lymphedema. Based on our growing knowledge of the pathophysiology of lymphedema, microsurgical techniques are used at the time of axillary lymph node dissection to perform a lymphovenous bypass between transected, leaking lymphatic channels and an adjacent, small calibre vein in the axilla. Using several objective metrics for short- and long-term surveillance, patients are monitored for the development of postoperative lymphedema. Early outcomes from using this technique have been promising, both in the literature and within our own institutions, demonstrating significant improvements in rates of postoperative lymphedema. However, future study is still required to better understand the long-term efficacy of immediate lymphatic reconstruction.

Immunoreactivity and a new staining method of monocarboxylate transporter 1 located in endothelial cells of cerebral vessels of human brain in distinguishing cerebral venules from arterioles.

Distinguishing brain venules from arterioles with arteriolosclerosis is less reliable using traditional staining methods. We aimed to immunohistochemically assess the monocarboxylate transporter 1 (MCT1), a specific marker of venous endothelium found in rodent studies, in different caliber vessels in human brains. Both largeand small-caliber cerebral vessels were dissected from four autopsy donors. Immunoreactivity for MCT1 was examined in all autopsied human brain tissues, and then each vessel was identified by neuropathologists using hematoxylin and eosin stain, the Verhoeff’s Van Gieson stain, immunohistochemical stain with antibodies for α-smooth muscle actin and MCT1 in sequence. A total of 61 cerebral vessels, including 29 arteries and 32 veins were assessed. Immunoreactivity for MCT1 was observed in the endothelial cells of various caliber veins as well as the capillaries, whereas that was immunenegative in the endothelium of arteries. The different labeling patterns for MCT1 could aid in distinguishing various caliber veins from arteries, whereas assessment using the vessel shape, the internal elastic lamina, and the pattern of smooth muscle fibers failed to make the distinction between small-caliber veins and sclerotic arterioles. In conclusion, MCT1 immunohistochemical staining is a sensitive and reliable method to distinguish cerebral veins from arteries.

Role of Bypass with Preoperatively Diagnosed Small Caliber Veins in Chronic Limb-Threatening Ischemia

In chronic limb-threatening ischemia (CLTI), although recent studies suggested that limbs classified as a higher Wound, Ischemia, foot Infection (WIfI) stage would benefit more from bypass surgery than endovascular therapy (EVT), graft unavailability is a major limitation for bypass. However, such graft unavailability is not clearly defined. This study aimed to assess whether bypass with veins judged as small by preoperative ultrasound is acceptable to achieve wound healing. Ninety-five limbs classified as WIfI stage 3/4 that underwent infrainguinal bypass with veins were enrolled and divided into two groups based on the preoperative inner diameter of veins. Those with a diameter <2.5 mm were classified as small caliber grafts (SMGs, n=28) and those with a diameter ≥2.5 mm as sufficient caliber grafts (SUGs, n=67), and wound-related outcomes were evaluated. Wound healing rate (WHR) was analyzed in all cohort, and wound recurrence-free rate (WRF) and wound recurrence-free amputation-free survival rate (WRAFS) were calculated for limbs that achieved wound healing. A propensity score matched analysis was also performed to minimize the background difference, and 21 matched pairs were included for the analysis. Although the primary patency rate was significantly worse in SMGs (1-year patency, Crude model: 82.1% in SUGs and 51.0% in SMGs, P=0.0003; matched model: 77.7% in SUGs and 41.6% in SMGs, P = 0.005), the secondary patency rate was maintained in the equivalent level (1-year patency, Crude model: 81.8% in SUGs and 83.1% in SMGs, P=0.26; matched model: 77.7% in SUGs and 78.4% in SMGs, P = 0.24). One-year WHR was equivalent between the groups in both crude and matched models (Crude model: 87.0% in SUGs and 83.8% in SMGs, P=0.13; matched model: 66.3% in SUGs and 61.4% in SMGs, P = 0.65). One-year WRF and WRAFS were also equivalent (Crude model: WRF, 95.9% in SUGs and 100% in SMGs, P = 0.71; WRAFS, 87.2% in SUGs and 88.0% in SMGs, P = 0.78. Matched model: WRF, 100% in SUGs and 100% in SMGs, P = 0.85; WRAFS, 92.9% in SUGs and 78.6% in SMGs, P = 0.38). Although bypass with small caliber veins showed an inferior primary patency rate, WHR and WRF were equally good if grafts are maintained patent. Bypass with small caliber vein grafts would be an important option to achieve wound healing.

The Pre-dilatation of vessels: A simple method to recruit small caliber veins for creating distal fistulas

Maturation failure remains a major clinical problem of distal arteriovenous fistula (AVF). Early failure (EF) is associated with the small size of the veins. For about 10 years we have used in more than 1000 fistulas, the Vessels Pre-Dilatation (VPD) to increase the recruitment of small veins for creating distal AVFs. The purpose of this study is to highlight if the VPD can reduce the incidence of EF or failure to mature (FTM) in AVFs created with small veins. Data of all the consecutive patients directly admitted to our Department for their first distal AVF from January to December 2019 were collected. The patients were divided in two groups, one with a vein diameter after the tourniquet ⩽2.0 mm (G1) and one >2 mm (G2). Both in G1 then in G2 the vessels had undergone VPD. Immediate failure (IF), EF, FTM, delayed or arrested maturation rate (DAM), unassisted AVFs and matured AFVs were evaluated. The patients recruited totalled 104, 37 in G1, and 67 in G2. The two groups were homogeneous in age, incidence of diabetes, obesity, heart disease, peripheral vasculopathy, and race. Female were more numerous in G1 (51% vs 12%, p < 0.001). In G1 and G2 occurred respectively 3 IF versus zero (p < 0.05), 10 EF (29%) versus 6 (9%) (p < 0.05), 6 DAM (16%) versus 6 (9%), 21 unassisted AVFs (57%) versus 57 (85%) (p < 0.01). Dividing the patients into groups of unassisted and assisted AVFs, female and low vein diameter are more represented in the assisted group. There were 32 matured AVFs (86%) in G1 and 65 (97%) in G2. In order to increase the incidence of the distal AVF, the PDV allows to include small veins. However, more patients require further interventions to achieve maturation of the fistula.

Outcome of Permanent Vascular Access with Vein ≤ 2.2mm in Diameter.

End-stage renal disease patients with vein diameter of ≤2.2mm can undergo autogenous arteriovenous fistula (AVF) formation with the acceptable results. This observational retrospective study of prospectively collected data analyzed end-stage renal disease patients with a vein diameter of ≤ 2.2mm, who underwent AVF formation at Shifa International Hospital Islamabad from January 2009 to December 2017. The fistulae were observed for immediate success and maturity at 3months. The chi-square test was used to determine the effect of vein diameter on final maturity. All data were analyzed using SPSS. The total number of patients with vein diameter of ≤2.2mm was 38, with a mean age of 46.76 ± 12.790years. Vein diameters ranged from 1.6 to 2.2mm. Immediate success was observed in 35 (92.1%) cases. Veins of 31 (81.6%) patients showing maturity at 3months and were used for hemodialysis. The overall success rate for the small caliber veins was 82%. Although end-stage renal disease patients present late with very small diameter veins, these veins should still be accommodated for permanent vascular access, because their maturity rates are still acceptable, even though these are lower than those of patients with adequate sized veins.

The utility of venous bifurcation for anastomosis with small-caliber veins in distal forearm radiocephalic arteriovenous fistula: Retrospective analysis of 52 fistula cases

Context: Distal forearm radiocephalic (RC) arteriovenous fistula (AVF) is the gold standard for vascular access for hemodialysis. The use of venous bifurcation to facilitate anastomoses in small-caliber vessels is well known in microvascular surgery. Small-caliber cephalic vein (CV) is frequently encountered during AVF creation in the distal forearm. We present here the utility of this technique for the creation of distal RC AVF in small-caliber CVs. Objective: The objective was to assess the utility of venous bifurcation for distal forearm RC AVF creation in small-caliber CV. Methodology: Fifty-two cases with CV diameter

Influence of the caliber in Endoscopic Saphenous Vein Harvesting during Coronary Artery Bypass Grafting

BackgroundThe required high degree of technical expertise is much more with the small caliber saphenous vein (SV) grafts using Endoscopic Saphenous Vein Harvesting (ESVH) during CABG Surgery and the patency may be affected. We thought to compare these small caliber vein grafted patients (GroupI) regarding their operative difficulties and mid-term graft patency with a controlled normal caliber grafted patients (groupII). MethodsRetrospective data collection was from June 2013 to June 2016 in a consecutive order after exclusion of the first 50 patients done in our center. A cutoff point of 3 mm diameter of the SV was identified. GroupI (<3 mm) (34patients) was compared to GroupII (>3 mm) (100patients). ESVH procedure time and SV characteristics were compared between the groups and the incidence of perioperative myocardial infarction as well as the Myocardial Perfusion Imaging (MPI) for the mid-term patency rate. Patients who had been commented as having clinical varicosity and those who refused the (MPI) evaluation during the follow up period were excluded. ResultsSignificant difference in the number of side branches and repaired small avulsed branches (GroupI vs. GroupII)(11.7 ± 4.8 vs. 9.7 ± 3.4) (P < 0.01) and (5.7 ± 1.7 vs. 1.7 ± 0.9) (p = 0.001) respectively. SV harvested required a longer time (min.) for total preparation (54.5 ± 14.8 vs. 39.9 ± 13.9 min) (p < 0.001) whereas the time required for endoscopy did not differ. The overall incidence of peri-operative myocardial infarction was (2.2%) with no significance between both groups. Normal/Mild ischemia in the territory of the venous graft (s) occurred in (88.2% vs. 91%) after a follow up period of (15.3 ± 7.9 m) that was non significant. ConclusionsESVH is feasible regardless the SV caliber with good mid-term patency rate in CABG patients. Small caliber SV needs longer time and more experience to be ready for usage but its quality can be better. The possibility of scoring the SV is difficult to be completely achieved except in the Operating Theater.

Primary Balloon Angioplasty Combined with Balloon-Assisted Maturation of Autogenous Arteriovenous Fistula in Patients with Small-Caliber Vasculature

Background: Failure or delayed maturation of arteriovenous fistula (AVF) in patients with end-stage renal disease (ESRD) who require hemodialysis (HD) can lead to catheter-related complications as bacteremia and sepsis with the resultant high morbidity and mortality. Small- diameter veins are often a limiting factor for the successful creation of arteriovenous fistulas (AVFs). Balloon-assisted maturation (BAM) is a recent, innovative, yet controversial method for developing autogenous arterio-venous fistulae (AVF). Purpose: Is to evaluate the use of intraoperative primary balloon angioplasty (PBA) as a technique to upgrade the small-caliber or diameter veins during AVF construction in conjunction with sequential balloon- assisted maturation to salvage failing fistulas, expedited maturation & improve the patency of AVFs. Materials and methods: Prospectively collected data over a 2-year period. Between January 2016 and December 2017, 121 patients who underwent AVF creation in two tertiary referral hospitals in Saudi Arabia, Vascular surgery Department, Nile Insurance Hospital & Vascular Surgery Unit, Benha University/Department of Surgery, Egypt, were retrospectively analyzed. The duration to maturation of the AVF was determined by comparing the period between the time of creation of the fistula and the first successful cannulation of the fistula for patients with ESRD on hemodialysis. Patients with peritoneal dialysis were excluded. Patients who underwent BAM or construction of AVF at an outside institution were excluded. Follow-up consisted reviewing of postoperative AVF duplex for patency, hemodialysis units, vascular and nephrology clinics databases, and telephone interviews. Successful outcome was determined as the functional ability to use the fistula for hemodialysis without surgical revision. Results: Of the 136 PBA procedures, 119 (87.5%) remained patent and subsequently underwent BAM with a resulting functional AVF. These consisted of 106 of the original AVFs and 13 new AVFs created at other sites. Occlusions occurred in 30 of the 121 fistulas (24.8%), and 15 were salvaged using BAM techniques. The mean balloon diameter for all dilatations was 3.5 mm. Of the initial 121 AVFs placed, 106 (87.6%) were made functional and 30 failed due to occlusion. Fifteen were salvaged using recanalization techniques and sequential BAM. Of the remaining fifteen patients, 11 were unsalvaged and received AVFs at another site using PBA and BAM techniques and 4 required graft placement. One AVF had to be ligated secondary to steal syndrome with insertion of chronic hemodialysis catheter as an alternative access. Overall 116 patients (95.9%) received working AVFs. All fistulas were functioning at 90 days after the final BAM. Graft placement was necessary in only 4 of the 121 patients (3.3%). Conclusion: The combination between PBA and BAM is an overall approach that facilitates AVF maturation, improves function, prolongs patency, and facilitates use of small-caliber veins as an autogenous vascular access. The shorter maturation times have reduced the overall need for indwelling catheters with their associated risks. The resulting large-diameter AVFs are easy to cannulate and are associated with improved flow and patency rates. Successful AVFs have been created using veins that would have otherwise been deemed unusable. Adoption of this conjoint technique should help meet the stringent demands for autogenous access placement defined by KDOQI and Fistula First Breakthrough Initiative (FFBI) and, thereby, improve the duration and quality of life for the hemodialysis patients

CADASIL RAPIDLY ACCELERATED BY HYPOTENSION POST-TRAUMA: AUTOPSY REVEALS IMPORTANT CONTRIBUTION OF BOTH ARTERIES AND VEINS IN WHITE MATTER PATHOLOGY

Vascular reactivity of subcortical arteries is impaired in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). This ‘earthen pipe’ state impairs autoregulation with dependency on blood pressure for brain perfusion. Chronic hypoperfusion can cause ischemic damage but less is known about the effects of acute hypotension. Additionally, the contribution of veins has been overlooked in conditions with leukoaraiosis, in general (including Alzheimer’s disease), and in CADASIL specifically. We describe the imaging and pathological findings of a case in whom CADASIL was dramatically accelerated following acute episodes of hypotension. Interestingly, venous collagenosis was demonstrated in the periventricular white matter regions. Case report with neuroimaging and pathological data. A 61-year-old man with genetically confirmed CADASIL was initially lucid following a motor vehicle accident but subsequently became hypotensive (60/40 mm Hg) due to an open femur fracture, and required intubation. Multiple new white matter infarcts appeared on brain imaging. A second hypotensive episode days later was associated with new coin-sized infarcts in the bilateral corona radiata and cerebellar peduncles, and resulted in quadriplegia. No embolic source was found on cardiac or vascular imaging. He expired within 5 weeks of the trauma. Autopsy revealed extensive subcortical and periventricular leukoencephalopathy, and multiple cavitations involving deep subcortical grey and white matter. Small arteries had thickened walls, disruption of the muscularis and intimal PAS-positive material (Fig 1A). Both larger periventricular and small caliber veins had thickened walls that were PAS-negative and trichrome-positive, consistent with venous collagenosis (Fig 1 B,C). There was no pathological evidence of global hypoxia or diffuse axonal injury. The findings suggest rapid acceleration of CADASIL pathology from acute hypotension in the setting of impaired vasoreactivity. Additionally, collagenosis of veins in the affected white matter regions is a novel finding not yet reported in CADASIL, to our knowledge. A few reports have suggested an integral role of collagenized veins in age-related leukoaraiosis and this may also apply to CADASIL. This case underscores the importance of blood pressure regulation in patients with CADASIL and highlights the potential importance of veins in white matter pathology. Cerebral arterial and venous pathology in white matter hyperintensities in CADASIL A. Arteriole containing PAS positive granular material within the media (arrow). B. Collagenosis of periventricular veins (arrows) highlighted by Masson's trichrome. C. The collagenized veins (arrows) do not contain the PAS positive material within their collagenized walls.

76 Analysis of the ophthalmic artery doppler indexes in chronic arterial hypertension pregnant women

Objective To assess the Doppler indexes of the ophthalmic artery in pregnant women who have been diagnosed with chronic arterial hypertension, as well as to compare these data with a group of non-hypertension pregnant women and to identify the cut-off points for differentiating between the indexes of both groups. Method This investigation refers to transversal observational study, which assessed 220 pregnant women who have chronic arterial hypertension as well as non-hypertension pregnant women in their second and third trimesters constituting, respectively, the study group and the control group. All the patients underwent Doppler evaluation of the ophthalmic artery, with an evaluation of the resistance indexes (IR), pulsatility (IP), and ratio between velocity peaks (RPV). Results There was a meaningful difference between the averages of the Doppler indexes of the ophthalmic artery between the two groups assessed; showing lower IR and IP values and higher RPV in the study group in relation to the control group and it was possible to identify cut-off points for differentiation between the indexes of both groups Conclusion There are flow alterations in the ophthalmic arteries of pregnant women who have chronic arterial hypertension, represented by signs of moderate vasodilatation and impedance fall in the orbital territory, the fact which can be extrapolated for the small-caliber veins of the central nervous system, considering the ophthalmic arteries belong to the central nervous system. As to the discrimination between the groups, the ratio between velocity peaks has shown to be the best index

Pre-analytical errors in blood sampling: an observational study on specimen collection technique and laboratory results

Around 60-70% of diagnostic and therapeutic decisions are based on blood exams. Several errors occur during the pre-analytic phase. of this study were: to describe nurses' behaviours in blood specimen collection; to describe prevalence and type of pre-analytical errors; to assess the association between pre-analytical errors and occurrence of unsuitable specimens. An observational cross-sectional study was conducted by means of a structured form based on up-to-date clinical recommendations. A researcher observed nurses' behaviors during 172 blood sampling procedures in medical, surgical and emergency care settings. Unsuitable procedures were registered. Most behaviours were correct, however some significantly diverged from recommended practices: active and passive patient identification; respect of antiseptic solution's drying time; rapid removal of tourniquet when blood started flowing. The prevalence of unsuitable specimen reports was significantly higher when the procedure involved a small calibre vein (RP: 0.19; IC95% 0.04 - 0.98; p = 0.03) and when blood drawing was difficult (RP; 3.83; IC95% 1.63 - 9.01; p <0.001). The pre-analytical phase is important for the diagnostic process and safety of patients. Although some factors – as patients' characteristics – are non-modifiable, some nurses' behaviours could be improved to reduce risk of pre-analytical errors. Further studies are needed to clarify the associations between pre-analytical errors and laboratory outcomes.

Use of short prosthesis segments for brachiocephalic arteriovenous fistulas in elderly hemodialysis population

IntroductionThe autogenous brachiocephalic fistula is a recognized secondary access for hemodialysis. However, veins in the antecubital fossa are often damaged, due to repeated venipunctures and subsequent scarring. Sometimes their anatomy does not enable successful arteriovenous fistula creation. In cases when the proximal part of the cephalic vein seemed patent, during ultrasound Doppler examination, we decided to use a short segment of 6 mm polytetrafluoroethylene graft to connect the vein with the brachial artery. We report our series of this procedure.Material and methodsOver an 8-year period, 34 patients underwent such an operation. Grafts were anastomosed either to the end of the cephalic vein or to the side. The decision was made based on the vein condition: small-caliber veins were considered better for the end-to-side anastomosis. All procedures were performed under local anesthesia, and were well tolerated.ResultsThirty-three fistulas were successfully cannulated at 2-8 weeks after the operation. Fistula patency rates were 84%, 73% and 55% at 12, 24 and 36 months. Comparison of two anastomosis types showed differences, 50% and 62.8% at 36 months, yet without statistical significance (p = 0.27, log-rank test). Fistula patency was not influenced by patient's age, sex or comorbidities.ConclusionsThe described procedure provides satisfactory cumulative patency with an acceptable complication rate. It can enhance the number of cephalic veins used with its main advantages of simple surgical technique and low perioperative morbidity.

Enfermedad sistémica relacionada con inmunoglobulina G4: ¿por qué interesa al reumatólogo?

Immunoglobulin G4-related systemic disease is a recently defined emerging disorder characterized by a diffuse mass-forming inflammatory reaction. The mass can be solitary or multiple. This entity affects the exocrine glands, lymph nodes and extranodal tissue, with a lymphoplasmacytic infiltrate rich in IgG4-positive cells, fibrosclerosis and obliterative phlebitis affecting medium and small caliber veins. Elevation of serum IgG4 is often present, but not always. The clinical features are highly variable, as this entity can affect single or multiple organs, with a synchronous or metachronous pattern. Two of the most frequent characteristics are the presence of a mass or localized inflammation, and a past history of allergic disease. Diagnosis requires integration of clinical, serological, imaging, histopathological and immunohistological data. Treatment is based on high-dose corticosteroids with subsequent de-escalation. This treatment is usually effective initially but disease flares are frequent. Rheumatologists should suspect IgG4-related systemic disease in patients referred to exclude connective tissue disease because of repeated inflammatory processes in distinct sites of localization.

Balloon Angioplasty to Facilitate Autogenous Arteriovenous Access Maturation: A New Paradigm for Upgrading Small-Caliber Veins, Improved Function, and Surveillance

Balloon angioplasty maturation is emerging as an important method to increase utilization and improve function of autogenous arteriovenous hemodialysis accesses (AVFs). Through the sequential dilation of small veins, large-diameter AVFs can be created with the inherent benefits of easier cannulation, greater overall surface area, improved patency, and fewer complications. A usable AVF can be created in a shorter amount of time, decreasing the need for dialysis catheters. In addition, selective angioplasty of the AVF inflow and outflow can facilitate improved flow rates and increase access longevity. Our approach, including primary balloon angioplasty during AVF creation, sequential balloon angioplasty maturation, and surveillance fistulagrams will be presented.