bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the relationships between dialog patterns and user satisfaction in customer service chat systems based on chat log analysis
Authors: Jiang Tingting , Guo Qian , Wei Yuhan , Cheng Qikai , Lu Wei
Published: September 2022

While previous studies of customer service chat systems (CSCS) understood user satisfaction as individuals’ subjective perceptions and depended heavily on self-report methods for satisfaction measurement, this article presents an obtrusive chat log analysis that followed the established approaches of search log analysis and examined the relationships between dialog patterns and user satisfaction. An 81-day chat log was obtained from a real-world CSCS that involves both a chatbot and human representatives. A total of 75,918 chat sessions/147,972 sub-sessions containing 251,556 user messages and 349,416 system messages were extracted after data processing and analysed in terms of topic, length and path. As found in this study, the users were more likely to get satisfied on low-difficulty topics. The dialog between the CSCS and users was shallow in general. While human representatives’ elaboration contributed to user satisfaction, the chatbot was responsible for damaging user satisfaction. The significance of this study consists not only in providing objective evidence about user satisfaction in online chat but also in generating practical implications for the CSCS to improve user satisfaction.
Impact of balloon predilatation in patients with reduced versus preserved ejection fraction during transcatheter aortic valve implantation
Authors: Elnaggar Heba M. , Schoels Wolfgang , Mahmoud Marwan S. , Kishk Yehia T. , Kullmer Matthias , Dia Mohamad , Algowhary Magdy
Published: September 2022

Background

Although there is a trend toward direct transcatheter aortic valve implantation (TAVI), still balloon predilatation is necessary in some cases, especially in patients with severe calcification. However, predilatation including rapid ventricular pacing may have adverse outcomes, especially in patients with reduced ejection factor (EF).

Objective

To evaluate the impact of predilatation on in-hospital outcomes in patients with reduced versus preserved EF underwent TAVI.

Methods

This was a prospective observational study including 110 patients (72 patients with preserved EF (≥50%) and 38 patients with reduced EF (<50%)) who underwent TAVI. The two groups were compared regarding in-hospital outcomes.

Results

Predilatation was done routinely in all 110 patients. The mean age was significantly higher in patients with preserved EF (82.76  ±  5.74 vs. 80.13  ±  6.51 years; p = 0.03). The majority (51.4%) of patients with preserved EF were females but the majority (73.7%) of those with reduced EF were males ( P < 0.001). Predilatation showed no statistical difference regarding in-hospital mortality (2.6% vs. 1.4%; p  =  0.29), hemodynamic instability (5.3% vs. 0.0%; p = 0.11), stroke (0% vs. 1.4%; p = 0.67), conduction defects (13.2% vs. 19.4%; p = 0.29), permanent pacemaker implantation (7.9% vs. 5.5%; p = 0.45), paravalvular leakage (5.3% vs. 2.8%; p = 0.42), vascular complications (7.9% vs. 11.1%; p  =  0.43), and acute kidney injury (7.9% vs. 7%; p  =  0.4) in patients with reduced versus preserved EF, respectively.

Conclusion

When balloon predilatation is inevitable during TAVI it is safe in patients with reduced as well as preserved EF with no added risk of hemodynamic instability or other outcomes.
High-Quality Inclusion in Preschool Settings: A Survey of Early Childhood Personnel
Authors: Steed Elizabeth A. , Rausch Alissa , Strain Phil S. , Bold Ellie , Leech Nancy
Published: September 2022

We utilized a survey to explore how early childhood personnel delivered high-quality and inclusive preschool special education and related services to young children with disabilities in one U.S. Western state. We conducted quantitative analyses on 418 participants’ survey responses, including t tests and Mann Whitney tests to examine differences in the use of high-quality inclusion practices between early childhood special educators (ECSEs) ( n = 209) and related service personnel (RSP) ( n = 209). Findings indicated that ECSEs were more likely than RSP to implement high-quality inclusion practices. All personnel reported inconsistent use of teaming practices. Services were provided most often inside the classroom with peers; however, several personnel provided support to children inside their classroom but in a separate space or outside of their classroom. We discuss findings in the context of ways in which early childhood personnel can be supported to use high-quality inclusion practices.
Branding the Earth: Selling Earth system science in the United States, 1983-1988
Authors: Barton Jenifer
Published: September 2022

As part of its efforts to find new relevance in the early 1980s, NASA formed the Earth System Sciences Committee (ESSC) to develop a large-scale Earth science research program that would use satellites and computer modeling to study the planet as an integrated system with interconnections between the land, air, water, and biota. Called Earth system science (ESS), the project was conceived on the scale of the U.S. moon missions. Like the Apollo program, it would need enormous government funding to implement. Yet, the project was proposed just as government science funding was contracting. Conscious of the changing political economy of science, the ESSC attempted to build scientific, political, and public support for its project by using promotional techniques akin to the branding efforts more commonly identified in corporate marketing that were themselves changing in scope and importance in the 1980s. These techniques formed part of the ESSC’s broader management strategy to promote ESS. The ESS brand was developed around the ideals of an interconnected ‘Earth system’, the significance of interdisciplinary research, and environmental concern. Though ESS failed to gain widespread traction, an unintended consequence of this branding was the communication and entrenchment of the concept of the ‘Earth system’. Today, this concept provides crucial theoretical scaffolding that unifies interdisciplinary Earth science research, including climate change science.
Comparison of Walking Biomechanics After Physical Therapist–Led Care or Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Secondary Analysis From a Randomized Controlled Trial
Authors: Grant Tamara M. , Diamond Laura E. , Pizzolato Claudio , Savage Trevor N. , Bennell Kim , Dickenson Edward J. , Eyles Jillian , Foster Nadine E. , Hall Michelle , Hunter David J. , Lloyd David G. , Molnar Robert , Murphy Nicholas J. , O’Donnell John , Singh Parminder , Spiers Libby , Tran Phong , Saxby David J.
Published: September 2022

Background:

Femoroacetabular impingement syndrome is characterized by chondrolabral damage and hip pain. The specific biomechanics used by people with femoroacetabular impingement syndrome during daily activities may exacerbate their symptoms. Femoroacetabular impingement syndrome can be treated nonoperatively or surgically; however, differential treatment effects on walking biomechanics have not been examined.

Purpose:

To compare the 12-month effects of physical therapist–led care or arthroscopy on trunk, pelvis, and hip kinematics as well as hip moments during walking.

Study Design:

Secondary analysis of multi-centre, pragmatic, two-arm superiority randomized controlled trial subsample; Level of evidence, 1.

Methods:

A subsample of 43 participants from the Australian Full randomised controlled trial of Arthroscopic Surgery for Hip Impingement versus best cONventional (FASHIoN trial) underwent gait analysis and completed the International Hip Outcome Tool (iHOT-33) at both baseline and 12 months after random allocation to physical therapist–led care (personalized hip therapy; n = 22; mean age 35; 41% female) or arthroscopy (n = 21; mean age 36; 48% female). Changes in trunk, pelvis, and hip biomechanics were compared between treatment groups across the gait cycle using statistical parametric mapping. Associations between changes in iHOT-33 and changes in hip kinematics across 3 planes of motion were examined.

Results:

As compared with the arthroscopy group, the personalized hip therapy group increased its peak hip adduction moments (mean difference = 0.35 N·m/body weight·height [%] [95% CI, 0.05-0.65]; effect size = 0.72; P = .02). Hip adduction moments in the arthroscopy group were unchanged in response to treatment. No other between-group differences were detected. Improvements in iHOT-33 were not associated with changes in hip kinematics.

Conclusion:

Peak hip adduction moments were increased in the personalized hip therapy group and unchanged in the arthroscopy group. No biomechanical changes favoring arthroscopy were detected, suggesting that personalized hip therapy elicits greater changes in hip moments during walking at 12-month follow-up. Twelve-month changes in hip-related quality of life were not associated with changes in hip kinematics.
Clinical Outcomes of Ulnar Collateral Ligament Surgery in Nonthrowing Athletes
Authors: Rothermich Marcus A. , Pharr Zachary K. , Mundy Andrew C. , Fleisig Glenn S. , Mussell Eric A. , Ryan Michael K. , Bernier Hunter M. , Ostrander Brook , Slowik Jonathan S. , Emblom Benton A. , Cain E. Lyle , Dugas Jeffrey R.
Published: September 2022

Background:

Ulnar collateral ligament (UCL) surgery continues to demonstrate excellent clinical outcomes and a high return-to-play (RTP) rate with a low complication rate. Recent studies have demonstrated similar clinical outcomes for baseball players who have undergone either UCL reconstruction or UCL repair. In comparison, few studies have assessed the clinical outcomes of UCL surgery for nonthrowing athletes.

Purpose/Hypothesis:

The primary objective of this study is to provide clinical outcomes of UCL surgery performed in nonthrowing athletes at a single institution with a minimum 2-year follow-up. Our hypothesis was that these patients would have similar clinical outcomes, complication rates, and RTP rates when compared with throwing athletes.

Level of Evidence:

Case series; Level of evidence, 4.

Methods:

From our longitudinal elbow registry, 40 nonthrowing athletes were identified who underwent UCL surgery (repair or reconstruction) between 2011 and 2019. Participant characteristics were recorded: age, sex, laterality, arm dominance, sport, level of competition, and type of surgery (UCL repair or reconstruction). Outcomes included RTP rate and average time, American Shoulder and Elbow Surgeons (ASES) scores, and complications.

Results:

From the 40 patients eligible for inclusion in this study with a minimum 2-year follow-up, 37 (93%) were successfully contacted: 16 male (43%) and 21 female (57%). Mean ± standard deviation age at the time of surgery was 18.0 ± 3.7 years. From the 37 technical procedures, 28 (76%) were UCL repairs and 9 (24%) were UCL reconstructions. For these patients, 15 (41%) had partial tears, 20 (54%) had complete tears, 1 (3%) had a medial epicondyle avulsion, and 1 (3%) had an unspecified pathology. Sports included football (n = 11), gymnastics (11), cheerleading (7), wrestling (4), volleyball (2), basketball (1), and acrobatics (1). Quarterbacks were excluded from the football patients, as quarterbacks are throwing athletes. Level of competition included high school (n = 26), college (8), professional (2), and youth sports (1). The RTP rate was 93% (26/28) at a mean 7.4 months for UCL repair and 100% (9/9) at a mean 10.0 months for UCL reconstruction. Mean ASES scores were 94.4 and 98.7 for UCL repair and reconstruction, respectively. Complications were low, with 2 patients in the UCL repair group requiring ulnar nerve transposition for ulnar nerve paresthesia.

Conclusion:

In nonthrowing athletes, patients undergoing UCL repair and UCL reconstruction show favorable outcomes at minimum 2-year follow-up. RTP and clinical outcomes are consistent with previous studies in baseball players as well as a parallel ongoing study conducted on non–baseball throwing athletes.
The Effects of Increasing State Minimum Wage on Family and Paid Caregiving
Authors: Jutkowitz Eric , Lake Derek , Shewmaker Peter , Gaugler Joseph E.
Published: September 2022

Older adults may receive either or a combination of unpaid family/friend and paid caregiving. The consumption of family/friend and paid caregiving may be sensitive to minimum wage policies. We used data ( n = 11,698 unique respondents) from the Health and Retirement Study and a difference-in-differences design to evaluate associations between increases in state minimum wage between 2010 and 2014 and family/friend and paid caregiving consumed by adults age 65+ years. We also examined responses to increases in minimum wage for respondents with dementia or Medicaid beneficiaries. People living in states that increased their minimum wage did not consume substantially different hours of family/friend, paid, or any family/friend or paid caregiving. We did not observe differential responses between increases in minimum wage and hours of family/friend or paid caregiving among people with dementia or Medicaid beneficiaries. Increases in state minimum wage were not associated with changes in caregiving consumed by adults age 65+.
Community Policing in Schools and School Resource Officer Transparency
Authors: Curran F. Chris , Boza Lelydeyvis
Published: September 2022

Following increased attention to racial disparities in police use of force, national conversations have focused on the role of law enforcement, including in public schools. This study examines transparency with regard to the presence of law enforcement in schools. Leveraging novel school-level and district-level data from the state of Florida, this research shows that the majority of schools and about a third of school districts do not make information on law enforcement presence in schools publicly available. Furthermore, the study finds that schools and districts serving more White student bodies have higher levels of transparency around law enforcement than those serving less-White demographics, an important finding given the racialized context of current policy discussions around policing in US schools and society more broadly. These findings inform ongoing debates about law enforcement in schools while also raising implications for policy and practice around the racialized nature of government transparency.
Valacyclovir Neurotoxicity in Patients with End-Stage Renal Disease: Two Cases Reviewed
Authors: Gublo Bernadette , St Amand Amy Beth , Menon Anupama , Scalise Alissa A
Published: September 2022

Purpose: The objective of this case series is to highlight different manifestations of valacyclovir associated neurotoxicity (VAN) and demonstrate the importance of adjusting medication appropriately in patients with end-stage renal disease (ESRD) on hemodialysis to prevent these complications. Summary: Valacyclovir is a medication used to treat herpes zoster infection, commonly known as shingles. Valacyclovir is renally cleared and can accumulate in patients with renal dysfunction leading to severe side effects due to the prolonged half-life. VAN is a common adverse effect in patients with underlying kidney disease, that can be easily prevented if valacyclovir is properly dosed. This case series details the clinical outcomes of two elderly patients who were prescribed valacyclovir at six-times the recommended dose based on their renal function. Failure to reduce the dose of valacyclovir resulted in severe neurological and physical manifestations that required hospital admission and emergent hemodialysis. Conclusion: This case series details the importance of adjusting valacyclovir dose based on renal function. In patients with ESRD, the half-life of valacyclovir can be up to 14 hours, therefore hemodialysis should be utilized in severe cases of neurotoxicity to improve rapid excretion of the drug and promote rapid recovery from VAN.
Profile design and simulation verification of hard whirling tool for ZC1 worm machining
Authors: Yu Yaxin , Ji Xiaoyan , Dai Sheng , Zuo Dunwen , Song Shuquan
Published: September 2022

The profile of the hard whirling tool for ZC1 worm machining is challenging to design precisely. An inaccurate tool profile results in irreversible overcutting or additional machining allowance. This study aimed to develop an accurate tool profile design method and digital verification approach to enhance the quality of ZC1 worms. The precise measurement and axial section data acquisition of the worm are conducted. A tool profile design method is proposed based on the envelope of the equidistant axial section. The motion law of whirling is studied, and a 3D model generation procedure for worm teeth is developed. The effect of the tool profile design is verified, and the impact of cutting parameters on worm tooth profile error is analyzed. The results show that the presented tool design method can effectively avoid overcutting. The employed modeling approach of worm teeth provides an intuitive verification means for tool profile design. Variable cutting parameters lead to different machining errors, and the maximum error is less than 3 μm. Changing the cutting parameters will not induce macro profile error but will impact the micromorphology. These findings should be valuable for designing envelope machining tools with complex motion and realizing the superior performance of hard whirling for ZC1 worm machining.
The effect of aspect ratio on the inception of primary instabilities in the laminar regime wake of a D-shaped cylinder
Authors: Koppa Shivanna Naveen , Ranjan Pritanshu , Clement Shibu
Published: September 2022

A numerical investigation was performed to study the wake dynamics of a D-shaped cylinder, and the effect of the aspect ratio of the cylinder on the onset of primary instabilities was explored. The aspect ratio ( L/D) is varied by increasing the cylinder’s length ( L) while keeping the cylinder’s diameter ( D) constant. Five aspect ratios ranging from 1 to 3 in increments of 0.5 were considered for the present study. The essential variables are the Reynolds number (Re) and the aspect ratio (AR). The primary instability analysis was performed using the Stuart-Landau equation to determine the critical Reynolds number value where the instability sets in. At low Reynolds number, the flow is steady and symmetric; at critical Reynolds number, the flow experiences Hopf bifurcation resulting in a time-periodic flow. As the aspect ratio was increased, the critical Reynolds number over which the primary instability sets in was found to increase linearly in the present study. Increasing the aspect ratio leads to significant modification of the flow topology and force coefficients. For aspect ratio two, the wake is more streamlined and narrower leading to a drag reduction of 14.49%. The drag reduction magnitude diminishes with a further increase in aspect ratio due to increased surface area resulting in more friction drag. The phase diagram and Fast Fourier transform (FFT) analysis revealed a reduction in vortex shedding activity, and velocity fluctuations in the wake.
Enhanced mechanical behaviour and grain characteristics of aluminium matrix composites by cold rolling and reinforcement addition (Rice husk ash and Coal fly ash)
Authors: Olorunyolemi Oladipupo C , Ogunsanya Olusegun A , Akinwande Abayomi A , Balogun Oluwatosin A , Saravana Kumar M.
Published: September 2022

Aluminium matrix composites significantly benefit the manufacturing sector due to the high strength-to-weight ratio. However, grain refinement was one of the major problems faced by the research community and also as-cast AA6063 contained eutectic silicon with sharp, long elongated laths that consequently reduces strength and limit their applications. So, the prime novelty of this research work is to refine the grains by performing the cold rolling operation in AA6063 and incorporating rice husk ash and coal fly ash in the AA6063 matrix to break those eutectic laths which attributes to the enhancement of the mechanical properties. Rice husk ash and coal fly ash were chosen because they are economical, possess low density and are available in enormous quantities as solid waste by-products. They contain a substantial concentration of SiO2 and serve as a viable reinforcement for improving the mechanical properties of aluminium composites. In this research, the grain characteristics along with the mechanical properties of aluminium composites reinforced with rice husk ash and coal fly ash, produced by the stir casting technique were investigated. The reinforcements were added in varying concentrations (1.5 and 3.0 wt.%). Six specimens were fabricated of which five were cold rolled. Image J and Origin software was used in evaluating the average grain size of the fabricated alloys and their composites. The results were discussed with the help of grain size distribution and profile plots. Structural and composition studies were done using scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction spectroscopy. Hardness and tensile tests were performed on the fabricated composites. The outcome of this research reveals, AA6063-3 wt.% rice husk ash composite has improved hardness (84HV) and tensile strength (156 MPa). Moreover, the average grain size of 10.52 µm was the main reason for the attainment of enhanced mechanical properties.
Stent-Graft Design: The Good, the Bad and the Ugly
Authors: Chuter Timothy A. M.
Published: September 2022

10 years of experience with endovascular AAA repair has yielded important information regarding the relationship between stent-graft design and stent-graft performance. Commercially available systems differ in important ways. General conclusions regarding endovascular AAA repair need to be qualified by reference to a specific system, or systems. Nevertheless, one can draw conclusions regarding the observed effects of certain design features, some of which are common to several devices. For example: tapered, trackable delivery systems (≤20 French in diameter) rarely fail to traverse tortuous iliac arteries: transmural barbs provide the most secure means of proximal attachment, column strength is of little value; proximal stent migration is becoming the primary late failure mode; modular stent-grafts are more versatile than unibody stent-grafts; fully-stented graft limbs are less prone to thrombosis than unstented graft limbs, iliac implantation and low porosity are associated with lower rates of aneurysm dilatation in the absence of endoleak (endotension); any movement between the angle of a stent and the overlying fabric will lead to graft erosion; unpolished (black) Nitinol is prone to fracture; and a long trunk/short limb combination is more stable than a short trunk/long limb combination.
A Rabbit Model of Highkinetic One-Sided Pulmonary Hypertension Induced by Pott's Operation
Authors: Zhi-Ping Wang , Ya-Hui Zeng , Pei-Wu Sun , Cui-Wen Tong , Xi Zhang
Published: September 2022

This article presents a new rabbit model of pulmonary hypertension using rabbits. The left pulmonary artery of the rabbits was anastomosed on the descending aorta side-to-side and the proximal left pulmonary was banded. A portion of the arteries in the left upper lobe was ligated, and the majority of shunted blood was driven to the left middle and lower lobe. The left pulmonary hypertension was established in 86.7% of the rabbits within 1–3 months post operation and the left pulmonary hypertension was formed in all rabbits after 3 months post operation with pathological changes of pulmonary arteriole. The left pulmonary arterial pressure was higher than right pulmonary arterial pressure and the pathological changes were less evident in the right pulmonary arteriole.
Low Preoperative HSP70 Atrial Myocardial Levels Correlate Significantly with High Incidence of Postoperative Atrial Fibrillation after Cardiac Surgery
Authors: St. Rammos Kyriakos , Koullias George J. , Hassan Moustafa O. , Argyrakis Nikolaos P. , Voucharas Christos G. , Scarupa Steven J. , Cowte Tomas G.
Published: September 2022

Purpose of the study.

Atrial fibrillation after cardiac surgery is still a frequent encountered complication and has been associated with increased hospital length of stay and numerous postoperative complications. The pathogenesis of atrial fibrillation involves an overall sequence of perioperative events, collectively termed as ischemia-reperfusion injury. Heat-shock proteins have been found to provide increased protection during ischemia-reperfusion as well as increased postischemic cardiac functional recovery. We sought to determine whether preoperative atrial heat shock levels were correlated with the appearance of postoperative atrial fibrillation

Basic methods.

Preoperative atrial myocardial samples obtained just before cannulation from 101 patients were used to detect immunohistochemically the expression of heat-shock proteins. The derived results were compared statistically with the incidence of postoperative atrial fibrillation, its time of appearance, duration and resistance to administered antiarrhythmics.

Principal findings.

The overall incidence of postoperative atrial fibrillation was 22.3%. Of these patients, 58.3% had no detectable heat shock proteins in their cytoplasm, in sharp contrast with 100% of the patients with no atrial fibrillation who were positive for heat shock proteins ( p<0.01). Four percent of our patient group had prolonged atrial fibrillation (defined as duration >48 h). These patients had significantly less ( p<0.01) nuclear heat shock protein expression compared with the non-atrial fibrillation group. However, the difference of the heat shock protein expression between the prolonged atrial fibrillation and the rest of the atrial fibrillation patients was not significant ( p = 0.891).

Conclusions.

Our results indicate that patients with low preoperative atrial heat shock protein expression have a significantly greater incidence of postoperative atrial fibrillation. Heat shock protein expression did not, however, correlate with the onset of atrial fibrillation and the resistance to administered medications. Heat shock protein preoperative induction as a measure of myocardial preconditioning may potentially decrease the incidence of postoperative atrial fibrillation.
Spontaneous Perforation of a Non-Aneurysmal Visceral Aorta
Authors: Curi Michael A. , Skelly Christopher L. , Woo David H. , Desai Tina R. , Winterfield Roland , Gewertz Bruce L. , Schwartz Lewis B.
Published: September 2022

A 77 year-old woman with mild osteoarthritis and Sjögren's Syndrome presented to an outside hospital with mild abdominal and back pain. The initial computed tomography (CT) scan was essentially negative. The repeat CT scan after 1 week of medical therapy was suspicious for a contained rupture of the visceral aorta. She was emergently transferred to the University of Chicago. Emergent aortography confirmed the diagnosis and revealed wide patency of the visceral and renal arteries. Upon exploration, there was obvious rupture of the entire right posterior aortic wall at the level of the celiac axis with a large right retroperitoneal hematoma. Aorto-aortic bypass was performed. The visceral and renal vessels were revascularized using separate jump grafts to this ‘parallel aorta’. The patient tolerated the procedure well and was discharged after 12 days. Pathologic examination of the aortic wall was essentially negative. She is well on follow-up after 20 months. To our knowledge, this is the second reported case of spontaneous contained rupture of the visceral aorta.
Severe Hemolysis Due to Cloth Wear 23 Years after Aortic Valve Replacement on a Starr—Edwards Ball Valve Model 2320
Authors: Murakami Mikiko , Tanaka Hiroyuki , Watanabe Masazumi , Shimizu Masato , Sunamori Makoto
Published: September 2022

Despite iron substitution therapy, a patient developed severe hemolytic anemia 23 yr after insertion of a cloth-covered Starr—Edwards model 2320 aortic valve prosthesis. The prosthesis showed no sign of significant dysfunction. Upon removal, it showed extensive cloth wear on the inner surface of all three struts; one strut was completely denuded of its cloth covering. Hemolysis immediately resolved after replacement with a St Jude aortic prosthesis.
Left Retroperitoneal Approach for Aortic Surgery
Authors: Wheeler J. M. D. , Williams I. M. , Shandall A. A.
Published: September 2022

Twenty-eight consecutive patients underwent sugery of the abdominal aorta by the left retroperitoneal approach. There were 11 suprarenal. 12 juxtarenal, three complicated infrarenal aneurysms and two occlusive aortoiliac disease (considered to be at high risk) undergoing surgical repair. Twenty-one underwent a tube graft repair whilst seven had a bifurcation graft. There were five deaths in this series; four of which occurred in the initial 12 patients. In our initial experience using the left retroperitoneal approach the overall mortality rate was 17%, though this reduced to 6% for the latter half of the study. The retroperitoneal approach allows access to the supracoeliac aorta without the need for thoracotomy and this approach should be considered for all aortoiliac reconstructive surgery.

The transabdominal route to the abdominal aorta remains the most commonly used approach. However, the left retroperitonal approach offers advantages in high-risk patients and suprarenal and juxtarenal abdominal aortic aneurysms (AAA). This is our initial experience of 28 patients undergoing surgical repair of the abdominal aorta via the left retroperitoneal approach.
Femorofemoral Venous Bypass Graft for the Treatment of Venous Occlusion of the Common Femoral Vein in a Nine Year Old Boy
Authors: Coughlin P. A. , Kent P. J. , Kester R. C.
Published: September 2022

Unlike arterial disease, most vascular surgeons have very little experience in performing bypass procedures for venous obstruction especially when occurring in children. Given the lack of published literature when compared to arterial procedures, we report a successful venous crossover procedure following iatrogenic injury and subsequent occlusion of the right common femoral vein in a nine year old boy.
Endovascular or Open Surgery for Aortoiliac Occlusive Disease?
Authors: Schneider Peter A.
Published: September 2022

Endovascular and open surgical techniques form a spectrum of options for the optimal, current treatment of aortoiliac occlusive disease. The results of endovascular intervention are determined primarily by lesion characteristics and the associated pattern of occlusive disease while the results of open vascular surgery are more significantly influenced by the patients' comorbid conditions and surgical risk. Categorizing lesions according to severity enhances appropriate patient selection. The long-term success is higher with open surgery while the initial morbidity is lower with endovascular techniques. Open surgery is a better choice for patients with extensive occlusive disease and/or less severe comorbid conditions. Endovascular surgery is not as durable but offers a reasonable option for patients with focal disease and/or contraindications to surgery.
Direct Reconstruction of the Innominate Artery
Authors: Cherry Kenneth J.
Published: September 2022

Purpose of this study.

Occlusive disease of the innominate artery requiring reconstruction is relatively uncommon. Data concerning these lesions has come from retrospective reviews at larger institutions. The purpose of this paper is to review the most recent experience at the Mayo Clinic, as well as to review the experiences of other large centers in the recent past, and to determine which patients are benefited by direct reconstructions and which patients might be better served by indirect methods or by endovascular techniques.

Basic methods:

A retrospective analysis of the trends at the Mayo Clinic concerning reconstruction of the innominate artery since 1976 was undertaken. Two reviews from our institution, published in 1989 and 1999, of all patients seen since 1976, were analyzed. This retrospective analysis also included papers from other referral centers dealing with innominate artery reconstruction, both here and in France.

Principal findings and conclusions:

The great majority of patients with symptomatic disease of the innominate artery are well treated by direct reconstruction. Stroke and death rates are acceptable. Early results are excellent, and the durability of the operation is also excellent, with impressive stroke-free survival rates. There are subsets of patients who might be treated by medical techniques or techniques other than direct reconstruction, such as cervical reconstruction or endovascular repair. Coronary artery disease remains the main determinate of early and late morbidity.
Surgical Repair of Thoracoabdominal Aneurysms: Patient Selection, Techniques and Results
Authors: Gloviczki Peter
Published: September 2022

Background:

Repair of thoracoabdominal aortic aneurysms (TAAAs) continues to be a challenging task. Hemorrhagic shock, cardiac arrest and multisystem organ failures are the most frequent causes of death, and paraplegia and renal failure are the most devastating complications.

Methods:

Flawless surgical technique and the use of adjuncts to protect key organs including the brain, heart, spinal cord, liver and kidneys affect outcome. Perfection in exposure and suturing technique decreases bleeding complications, shortens cross-clamp time and assures optimal, visceral, renal and lower extremity perfusion. Technical details include retroperitoneal abdominal aortic exposure, double thoracotomy for Type I and Type II aneurysms, and preservation of the diaphragm. The kidneys are protected by perfusion of iced lactated Ringers; visceral ischemia in Type 1 and Type II, aneurysms is diminished by using pulmonary vein-femoral artery pump with sequential clamping. Spinal cord protection is attempted by spinal fluid pressure monitoring and drainage, moderate general hypothermia, selective left heart bypass, reimplantation of critical intercostal arteries, monitoring somatosensory and somatomotor evoked potentials and epidural cooling of the spinal cord.

Results:

Outcome in 203 patients (Group I) who underwent repair of TAAAs without epidural cooling was compared with outcome in 97 patients, 27 with thoracic aortic aneurysms and 70 with TAAA (Group II) who underwent repair using epidural cooling. In Group II paraplegia/parapesis occurred in 11.6%. not different from the 8.9% in Group I. Thirty day mortality for elective cases decreased from 14.6% (Group I) to 7.2% (Group II, P<0.05).

Conclusions:

Open surgical repair of TAAA carries elevated mortality and complication rates. The etiology of ischemic and reperfusion injury to the spinal cord is multifactorial and its prevention remains a formidable and as yet unresolved task. To select patients for surgical repair, the risk of TAAA rupture should be balanced against risks of perioperative mortality, paraplegia and renal failure.
Leukocyte Activation and Phagocytotic Activity in Cardiac Surgery and Infection
Authors: Rothenburger Markus , Trösch Frank , Markewitz Andreas , Berendes Elmar , Schmid Christof , Scheld HansHeinrich , Tjan Tonny D. T.
Published: September 2022

Background

Cardiac surgery (CS) using cardiopulmonary bypass (CPB) is associated with cellular and humoral defense reactions termed the systemic inflammatory response syndrome. Leukocyte activation is one of its causative mechanisms which may be aggravated by additional infection.

Methods and results

Eighty-five patients undergoing CS with CPB were prospectively investigated. Leukocyte counts, elastase. and phagocytotic activity were measured from 24 hpreoperatively up to 7 days postoperatively. Seventy-nine patients had an uneventful course (group 1) while six patients developed a systemic infection (group 2). Leukocytes and elastase levels increased postoperatively (p<0.01) and were significantly higher in group 2 (p<0.01). In both groups a decrease of leukocyte/elastase ratio occurred (p<0.002), no differences between groups were observed. The phagocytotic activity, representing the circulating cells of the reticuloendothelial system (RES), dropped on day 1 (p<0.05), and increased thereafter above baseline levels (p<0.001). No differences of RES function between groups was observed, the initial drop on day 1 in both groups was compensated by the quality of phagocytotic ability of each cells.

Conclusion

Leukocyte activation after CS with CPB occurs. It is associated with a regular RES function and similarly leukocyte/elastase ratios in both groups, suggesting an adequate immune response. Therapeutic interventions resulting in depletion of leukocytes to alleviate reperfusion injury might impair the immune response of those patients acquiring perioperative infection and should be approached with caution. Leukocyte depletion maybe effective in patients for whom an extended period of CPB was required. Further investigations to prove this hypothesis awaits confirmation.
Consequences of PTFE Membrane Used for Prevention of Re-Entry Injuries in Rheumatic Valve Disease
Authors: Ozeren Murat , Han Unsal , Mavioglu Ilhan , Simsek Erdal , Soyal M. F. Tolga , Guler Gulcin , Yucel Ertan
Published: September 2022

Background.

The value of polytetrafluoroethylene (PTFE) surgical membrane as a pericardium substitute in patients who undergo reoperation for rheumatic valve disease is reported in this observational study.

Methods.

PTFE was used for pericardial closure in 56 rheumatic valve patients. During reoperation of seven cases, adhesions were classified as none, minimal, moderate to severe and scored in the sections of heart. Data found at reoperations were collected prospectively in all patients.

Results.

Seven of 56 patients reoperated mean period of 67.1 ±23.4 (SD) months later. No infection, complication and operative or late death attributable to the membrane were observed. There were two right ventricular, three minimal right atrial and one innominate vein lacerations during resternotomy and all of them were controlled. During histological examination, a microscopically significant foreign body reaction was found.

Conclusion.

PTFE membrane produced an undesirable fibrous membrane that obscured the epicardial anatomy and hardened the dissection in patients with rheumatic heart disease.
CarboMedics Bileaflet Prosthesis, Experience with 165 Uneventful Implants
Authors: Alsaddique Ahmed A.
Published: September 2022

With the premise of better structural design, easy rotatability and less valve-related complications CarboMedics cardiac prosthesis (CarboMedics, Inc., Austin, Texas) was launched in 1986. We reviewed our experience with 165 implants in a group of mostly rheumatic heart disease patients with a follow-up period of at least seven years and a maximum of ten years. There was no hospital mortality, significant morbidity or thromboembolism and no patient to date has experienced any valve-related event. We conclude that the clinical performance is quite satisfactory and it improves the quality of life in patients with cardiac valve prostheses. We find the rotatability feature is particularly useful especially in situations where the entire mitral apparatus is preserved during mitral valve replacement.
Aorto-Caval Fistulas
Authors: Davidovic L. B. , Kostic D. M. , Cvetkovic S. D. , Jakovljevic N. S. , Stojanov P. L. , Kacar A. S. , Pavlovic S. U. , Petrovic P. L. J.
Published: September 2022

The surgical repair of 16 aorto-caval (A-C) fistulas (15 male and one female patient; average age of 61.3 years) is reviewed. Fourteen fistulas were caused by aneurysm's erosion, one by iatrogenic injury, while one followed abdominal blunt trauma. The interval from presumed occurrence to diagnosis ranged from 6 h to 2 years. The presence of an abdominal bruit (87.5%) was the most reliable physical finding. Congestive heart failure was prominent in three (18.7%) cases, while severe lower extremity edema in five (31.2%). Two patients (12.5%) had hematuria, two (12.5%) renal insufficiency, while four (25%) scrotal edema. The diagnosis was not recognized before the surgery in five (31.2%) cases. In all 16 cases after transaortic suture of the fistula, aortic reconstructions were performed. Four operative deaths (25%) occurred, in patients who were not correctly diagnosed before surgery. In one case the cause of death was massive bleeding, and in three MOFS. All other patients were followed from 1 to 17 years (mean 4 years and 2 months). All grafts are patent, and there is no lower extremity venous insufficiency or pelvic venous hypertension. Surgical repair of A-C fistulas is mandatory to prevent serious complications.
Single-Stage Unifocalization and Correction with Median Sternotomy in Complex Pulmonary Atresia
Authors: Tireli Emin , Basaran Murat , Kafali Eylul , Soyler Ilksen , Camci Emre , Dayioglu Enver
Published: September 2022

Objective:

This study assessed the surgical and post-operative outcome of single-stage complete unifocalization and repair procedure in patients with complex pulmonary atresia.

Methods:

From 1999 to 2001. we performed complete unifocalization and correction in 10 patients with complex pulmonary atresia. Their ages ranged from 10 months to 17 years. All patients were evaluated with pulmonary angiography and divided into two groups according to the development of native pulmonary arteries. Group I patients had hypoplastic pulmonary arteries and MAPCAs and Group II patients had only MAPCAs without native pulmonary arteries. With median sternotomy, all MAPCAs were prepared and anastomozed to native pulmonary arteries in group I patients or on a pericardial roll in group II patients without using cardiopulmonary bypass. Right ventricle to pulmonary arterial continuity was established with a valved conduit under CPB. VSD was closed in two patients.

Results:

Eight patients had complete repair without VSD closure. They were followed periodically with pulmonary angiography. Two patients developed congestive heart failure. One of them was reoperated and VSD was closed. The other patient died because of untraceable congestive heart failure. The decision for VSD closure was made in two patients due to suitable pulmonary arterial vascular tree. However, one of them had to be reoperated and VSD patch was removed. This patient died because of sepsis on the postoperative 26th day. We are following the rest of the patients with echocardiography and pulmonary angiography.

Conclusion:

Single stage complete unifocalization and repair should be the treatment of choice in patients with complex pulmonary atresia. This procedure provides a significant development in neopulmonary arterial system. However, the accurate criterias for VSD closure are still controversial. After the operation, these patients had to be followed closely with echocardiography and pulmonary angiography because of the absolute risk of congestive heart failure in patients with VSD left open.
Is Aortic Angiography Necessary for Accurate Planning of Endovascular Aortic Aneurysm Stents?
Authors: Brown Wendy A. , Miller Robert , Birch Simone , Scott Alan
Published: September 2022

Endovascular management of abdominal aortic aneurysms (AAA) relies upon accurate stent design. We hypothesized the length of the stent could be measured from computed tomogram (CT) generated 3D surface rendered images of the abdominal vessels, eliminating the need for digital subtraction angiography (DSA).

Methods

The CT scans from a consecutive series of 54 patients considered for endovascular AAA repair were reviewed. A TRIFAB Zenith (™Cook) endovascular aortic stent was designed, using the manufacturer's sizing computer program. These hypothetical stents were compared to those that had been implanted, using measurements from both angiogram and CT (Spearman's test of correlation ( p<0.05)).

Results

The stent body size and short limb extension (SLE) of stents in each group was similar (correlation coefficient 0.70( p<0.01) and 0.50 ( p=0.014)), however. CT alone significantly underestimated the length of the long limb extension (LLE) (correlation coefficient 0.095)

Conclusion

These data suggest that CT underestimates the tortuosity of iliac vessels. Aortic angiography is necessary for accurate AAA endovascular stent design.
Pelviureteric Junction Disruption as a Complication of Chemical Lumbar Sympathectomy
Authors: Antao B. , Rowlands T. E. , Singh N. P. , McCleary A. J.
Published: September 2022

Chemical lumbar sympathectomy is a commonly performed procedure in vascular surgery and pain management. This case report discusses the management of a patient who suffered pelviureteric junction disruption following phenol injection for ischaemic leg pain despite radiological evidence of correct placement.

The authors suspect this is an underreported complication, which could be relevant in obtaining informed consent.
Treatment of an Aortic Fungal False Aneurysm by Composite Stentless Porcine/Pericardial Conduit: A Case Report
Authors: Mahesh B. , Caputo M. , Angelini G. D. , Bryan A. J.
Published: September 2022

Fungal prosthetic valve endocarditis is an uncommon but serious condition with high early and long-term mortality. The majority of these cases occur after aortic valve surgery and are caused by Candida species. Radical debridement of all infected tissues, valve replacement with perioperative and long-term anti-fungal agents is the recommended treatment. Choice of prosthesis varies widely among surgeons, but present recommendations favour biological prostheses. We report for the first time the case of a fungal PVE with false aneurysm after composite aortic root replacement with a dacron composite conduit treated successfully with aortic root replacement using a Shelhigh (Shelhigh Inc., Millburn. NJ) stentless porcine pericardial valved conduit.
A Thymic Carcinoid Mimicking Acute Aortic Dissection
Authors: Vohra H. A. , Alzetani A. , Guha T. , Rosin M. D.
Published: September 2022

Thymic carcinoids are extremely rare. We present an 80 year old hypertensive patient who presented as an emergency with sudden onset of severe chest and upper back pain raising the suspicion of acute aortic dissection or acute coronary syndrome. Further investigations revealed a carcinoid tumour of thymic origin.
Combined Surgical Approach to Coexistent Carotid and Coronary Artery Disease: Early and Late Results
Authors: Vitali E. , Lanfranconi M. , Bruschi G. , Colombo T. , Russo C.
Published: September 2022

Background:

The management of patients with simultaneous coronary artery and carotid artery disease is still controversial.

Methods:

A retrospective review of the records and follow-up data of 139 consecutive patients undergoing simultaneous coronary artery bypass graft and carotid endarterectomy from 1981 to 1999 was carried out.

Results:

Early mortality was 2.1%, perioperative myocardial infarction and stroke rates were 2.8 and 1.4%, respectively. Survival at 7 years was 74.7 ±5.1% and event-free survival at 7 years was 67.9 ± 5.6%.

Conclusions:

The combined surgical approach has proved to be effective and safe allowing the treatment of both diseases in a single operative procedure.