Small Burr Research Articles

Does initial use of large versus small burr size in left main stem bifurcation impact clinical and procedural outcomes?

Abstract Background Coronary calcifications, detected in up to 25% of treated coronary lesions nowadays, has a well-known association with complications during PCI, particularly for left main stem (LMS) interventions. Current guidelines recommend coronary artery bypass grafting for patients with LMS disease, particularly with high SYNTAX score ≥ 33. However, in those with increased surgical risk, PCI can be used particularly with use of rota-ablation (RA). RA is a well-established treatment for heavily calcified disease particularly in non LMS sites. However, data on the safety and efficacy of use of RA in LMS bifurcation management is limited. Current guidelines recommend using a small burr size at the start, with upsizing burrs if required. Whether upfront use of large burr size ≥ 1.75 versus smaller burr size in this context in is safe or effective is unknown. Methods This was a retrospective, single centre, study. Included patients undergoing RA to LMS bifurcation disease. Standard procedures for RA were applied to each case, following current national and international intraprocedural standards. The main study outcomes were overall mortality at 1 year, and a comparison of mortality at 1 and 4 years between groups and repeat target lesion revascularization at 4 years. Results To our knowledge, this is the largest series of LMS rota-ablation cases, with the longest available follow up. Between June 2009 and October 2021, we included 243 patients with a mean age of 74.7±9 years. Males formed 80% of the cases. 51.4% of patients were treated with a large bur size ≥ 1.75mm, with more males being treated with large burr size. Most treated lesions were true bifurcations (85.6%). Treated lesions were complex (Syntax score = 35.3 ± 10.6). Radial access was used in almost two thirds of patients, with size 7F sheath being the most used. Intravascular ultrasound was more commonly used with large burr size (p = 0.017). Upfront 2-stent techniques, predominantly culotte, was employed more often with large burr size. Provisional technique was used more often in the small burr size group. The burr size to vessel size was 0.4 in small burr group versus 0.48 in large burr size using stent size as a surrogate for vessel size. Post dilatation balloons were larger as well as stent size in the large burr group. The overall 1-year mortality for the group was 12.7% similar to international literature. Importantly, procedural complications were not different between groups, and similarly mortality at 1 and 4 years, p = 0.082 and p = 0.384 respectively. There was no difference between groups in terms of repeat vessel revascularization at 4 years p=0.487. Conclusions Upfront use of large burr size ≥ 1.75 is feasible and safe to treat LMS bifurcation disease with no increase in procedural complications or mortality and target lesion revascularization on long term follow up. It is notable that in-hospital mortality for this cohort was low at 1.6% in comparison to previous studies.1 and 4 year mortality KM curves

Staged strategy of combined rotational atherectomy and intravascular lithotripsy for severely calcified lesions: an evaluation using multimodality intracoronary imaging—a case report

Abstract Background Severely calcified lesions are the most significant challenge for percutaneous coronary intervention, exhibiting poor clinical outcomes. Some severely calcified lesions remain untreatable with conventional balloons or even atherectomy devices. Intravascular lithotripsy is a new option for treating severe calcification. Case summary Herein, we describe a case of ischaemic cardiomyopathy with a thick, circumferential calcified lesion in the proximal and mid-segments of the left anterior descending coronary artery. In the first session, high-pressure balloons, cutting balloons, and rotational atherectomy failed to disrupt the calcification. In the staged additional treatment that was subsequently planned, eight cycles of intravascular lithotripsy created multiple fractures in the deep calcification, resulting in successful stent deployment. The effect of intravascular lithotripsy was observed mainly in calcified areas with lipid components detected using near-infrared spectroscopy-intravascular ultrasound. Discussion Our report suggests the efficacy of employing a combined strategy of rotational atherectomy with small burrs and intravascular lithotripsy in the treatment of severe calcification with a minimal risk of complications. Our study introduces a novel aspect by utilizing near-infrared spectroscopy-intravascular ultrasound to evaluate calcified lesions before performing intravascular lithotripsy. To our knowledge, there have been no similar reports to date. The effect of intravascular lithotripsy on calcified lesions may be related to the distribution of lipid components and/or heterogeneity within the calcification.

Purely Endoscopic Supracerebellar Infratentorial Approach to the Pineal Region in Pediatric Population.

Pineal lesions represent less than 1% of all brain tumors (Villani et al., Clin Neurol Neurosurg 109:1-6, 2007). The abysmal location and critical neurovascular structures remain a surgical challenge, despite the advent of microneurosurgery. The classical wide surgical suboccipital craniotomy with the supracerebellar infratentorial approach, described by Sir Victor Horsley (Victor, Proc R Soc Med 3:77-78, 1910), is infamous for its considerable surgical morbidity and mortality. This was later upgraded microneurosurgically by Stein to improve surgical outcomes (Stein, J Neurosurg 35:197-202, 1971).Ruge et al. reported the first purely endoscopic fenestration of quadrigeminal arachnoid cysts via this corridor (Ruge et al., Neurosurgery 38:830-7, 1996). A cadaver-based anatomical study by Cardia et al. demonstrated the viability for endoscope-assisted techniques (Cardia et al., J Neurosurg 2006;104(6 Suppl):409-14). However, the first purely endoscopic supracerebellar infratentorial (eSCIT) approach to a pineal cyst was performed in 2008 by Gore et al. (Gore PA et al., Neurosurgery 62:108-9, 2008).Unlike transventricular endoscopy, eSCIT approach poses no mechanical risk to the fornices and can be utilized irrespective of ventricular size. More vascular control and resultant reduction in uncontrolled hemorrhage improve the feasibility of attaining complete resection, especially around corners (Zaidi et al,, World Neurosurg 84, 2015). Gravity-dependent positioning and cerebrospinal fluid (CSF) diversion aid cerebellar relaxation, creating the ideal anatomical pathway. Also, angle of the straight sinus, tentorium, and tectal adherence can often influence the choice of approach; thus direct endoscopic visualization not only counteracts access to the engorged Galenic complex but also encourages sharp dissection of the arachnoid (Cardia et al., J Neurosurg 104:409-14, 2006). These tactics help provide excellent illumination with magnification, making it less fatiguing for the surgeon (Broggi et al., Neurosurgery 67:159-65, 2010).The purely endoscopic approach thwarts the dreaded risk of air embolisms, via simple copious irrigation from a small burr hole (Shahinian and Ra, J Neurol Surg B Skull Base 74:114-7, 2013). The tiny opening and closure are rapid to create, and the smaller wound decreases postoperative pain and morbidity. Recent literature supports its numerous advantages and favorable outcomes, making it a tough contender to traditional open methods.

Machining Temperature, Surface Integrity and Burr Size Investigation during Coolant-Free Hole Milling in Ti6Al4V Titanium Alloy

Modern Aircraft structures use titanium alloys where the processing of holes becomes essential to assemble aerospace parts. Considering the limitations of drilling, the study evaluates the helical milling for hole processing in Ti6Al4V. The experimental evaluation was conducted by considering burr size, surface roughness, machining temperature, and microhardness under coolant-free conditions. The axial feed and cutting speed were varied at three levels, and nine experiments were conducted. The results exhibit a lower machining temperature during helical milling than during drilling. In addition, the helical milling helped to lower the surface roughness and size of the exit burrs. However, helical-milled holes showed higher subsurface microhardness than conventionally drilled holes. The process variables were influential on machining temperature magnitude. The highest recorded temperature of 234.7 °C was observed at 60 m/min of cutting speed and 0.6 mm/rev feed. However, the temperature rise did not affect the microhardness. Strain hardening associated with mechanical deformation was the primary mechanism driving the increase in microhardness. Helical-milled holes exhibited an excellent surface finish at lower axial feeds, while chatter due to tool deformation at higher feeds (0.6 mm/rev) diminished the surface finish. The surface roughness increased by 98% when the cutting speed increased to 60 m/min from 20 m/min, while a moderate increment of 28% was observed when the axial feed increased to 0.6 mm/rev from 0.2 mm/rev. Furthermore, the formation of relatively smaller burrs was noted due to significantly lower thrust load and temperature produced during helical milling.

LMAP-18 ADAPTING LASER INTERSTITIAL THERMAL THERAPY (LITT) FOR TREATMENT OF INTRACRANIAL LESIONS IN CANINES

Abstract Malignant gliomas are devastating intracranial tumors with dismal prognoses that impose unique therapeutic challenges. Treatment options include surgical resection, radiation, and chemotherapy, but efficacy is limited and carries associated morbidity. Promise persists for newer modalities, such as immune-based platforms, but the blood-brain barrier (BBB) restricts intracranial therapeutic access, limiting success. Laser interstitial thermal therapy (LITT) is a minimally invasive surgical intervention permitting thermal ablation of brain tumors and other intracranial lesions. During LITT, a laser probe is stereotactically introduced through a small skull burr hole into the lesion. Continuous MRI is used to conduct real-time temperature monitoring via software-based calculation of cumulative thermal dosage zones. LITT is not only capable of ablating neoplastic tissue, but can also open the BBB in peritumoral regions, and thus may synergize with other emerging therapies. We adapted a commercially available LITT system (Monteris Medical) for use in dogs with intracranial lesions. Canine cadavers were used to optimize LITT procedures before employing this platform in live dogs. Our approach consists of 1. obtaining volumetric, T1-weighted, MRI studies to plan trajectories to intracranial targets, 2. fixing canine patients to a surgical bed and registering them for surface matching to a volume rendered image, 3. using an integrated instrument holder (Varioguide, Brainlab) to guide drilling of 4.5 mm skull burr holes for placement of self-tapping titanium “mini-bolts” (Monteris Medical), and 4. introducing the laser catheter probe through the mini-bolts for lesion ablation in the MRI suite. This method allows for rigid stereotaxy, successful neuronavigation, and a minimally invasive approach. We have successfully performed LITT on four canine patients with spontaneously occurring intracranial gliomas and plan to treat additional canine patients with intracranial lesions. Future studies will explore combination therapeutic platforms, including immunotherapy and gold nanoparticles to improve the efficiency and specificity of tumor ablation.

Incorrect management of a broken abutment screw


 Implant abutment screw fracture is an uncommon though challenging complication. A fractured abutment screw should be removed without damaging the threads of the screw channel to reuse the prosthesis.
 
 
 To retrieve the fractured part without severing the threads, various procedures have been proposed, such as to try to unscrew the fractured part using a strong, straight and pointed probe, or to prepare a small dent into the center of the fractured part using a small round diamond burr or a fissure burr in a counter clockwise motion. Various screw removal kits have been introduced to this aim, but with inconsistent results. 
 
 
 When a physician does not manage to remove the fractured screw in either way, he/she often chooses to either replace the implant, which can be an expensive option, or abandon the implant and cover it with soft tissue, which may lead to compromised function, phonetics, or esthetics. Instead, saving the implant would great benefit patients. To this aim, the conversion of the screw chamber into a dowel space for a dowel-core and crown restoration has been proposed, thanks to the aid of laser-welded titanium for example. Instead, other techniques do not seem to have been commonly accepted. 
 
 
 The aim of the present article is to present the incorrect management of a fractured abutment screw by a classic surtex post. 

Rotational atherectomy to left circumflex ostial lesions: tips and tricks.

Serious complications including vessel perforation may occur during rotational atherectomy (RA) to left circumflex (LCX) ostial lesions. In fact, if perforation occurs around LCX ostium, bailout procedures including deployment of covered stents may cause fatal ischemia in the territory of left anterior descending artery, which results in broad anterior acute myocardial infarction and subsequent death. In this review article, we described tips and tricks for RA to LCX ostial lesions. First, we should cautiously decide the indication for RA to LCX ostial lesions, because there are several reasons to avoid RA to LCX ostial lesions. Before procedures, we should estimate the difficulty of RA to LCX ostial lesions, which is mainly determined by the combination of the bifurcation angle and the severity of stenosis. Thus, the combination of the large bifurcation angle and the tight stenosis makes RA to LCX ostial lesions most difficult. Appropriate position of guide catheter and RotaWire is a key to successful RA to LCX ostial lesions. Differential cutting is an essential concept for RA to LCX ostial lesions. However, since there is no guarantee that differential cutting always works, small burr (≤ 1.5mm) would be a safe choice as initial burr for RA to LCX ostial lesions.

Effectiveness of using both rotational atherectomy with smallest burr and orbital atherectomy system for stentless treatment of calcified nodules.

Effectiveness of using both rotational atherectomy with smallest burr and orbital atherectomy system for stentless treatment of calcified nodules.

Pectoralis Major Tendon Repair: Transosseous Suture Technique

Background: Pectoralis major ruptures are rare injuries that occur in young men between 20 and 40 years of age, typically during resistance training in the eccentric phase of muscle contraction. As the incidence of these ruptures increases with increasing activity levels and use of anabolic steroids, it is important to understand effective repair techniques. Indications: Repair of the ruptured pectoralis major tendon is indicated for young, active patients seeking to regain full functionality of the affected upper extremity. Technique Description: In short, after the pectoralis major is identified, the insertion site is revealed just lateral to the biceps tendon. The site for the bone trough is then exposed through cauterization of superficial tissue, and a cortical bone trough is drilled vertically using a small round burr. The location of 3 pilot holes is identified just lateral to the cortical bone trough, and then the holes are drilled to allow for placement of the anchors later in the procedure. The tendon itself is then identified, and sutures are placed in the bulk of the muscle tendon in a Krackow fashion. After the tendon is properly sutured, it is placed under tension to test the structural integrity of the suture pattern and ensure proper load capacity. The sutures are then passed through the pilot holes, the tendon is pulled down into the trough, and the sutures are tied down to the bone. Results: After an appropriate rehabilitation protocol is followed for up to 6 months postoperatively, the transosseous suture technique in the context of pectoralis major tendon repairs allows for adequate tissue to bone healing and near-complete restoration of patient functionality and strength. Conclusion: Acute repair of pectoralis major tendon tears using a transosseous suture technique is effective in restoring upper extremity strength and functionality and is associated with high patient satisfaction. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Electron Microscopy and Elemental Analysis of Defective Drysdale Nucleus Manipulator Instruments Implicated in Surgical Complications

To analyze microtopography of 5 reusable Drysdale nucleus manipulator (DNM) paddled tips for sharp defects and evaluate their elemental composition to determine probable source, investigating 2 instruments (DNM 1 and 4) implicated in causing posterior capsule rupture (PCR) and 3 instruments with sharp edges identified by finger-tip interrogation intraoperatively. Experimental laboratory investigation. DNM paddled tips were analyzed using scanning electron microscopy (SEM) to evaluate for sharp surface defects (number, dimensions), and subsequently energy dispersive x-ray spectroscopy (EDS) performed on sharp defects to determine their elemental composition. All reused DNMs analyzed (5 of 5) had significant structural defects on SEM analysis including sharp burrs, cavities and indentations, surface debris or residues, and roughening, compared to the new instrument (DNM 3, control) which had no defects. DNM 1 had 2 sharp defects, a larger 14×76-µm one and a craterlike 167×220-µm defect containing debris. EDS found that DNM 2 had 3 of 4 burrs composed mainly of carbon, the fourth of mixed composition (calcium, sulfur, oxygen); DNM 4 had 1 small burr, EDS significant for carbon; DNM 5 had 3 prominent burrs, the largest of 20×28 µm, 2 composed of aluminum, and some carbon residue. DNM 6 had 1 burr composed of aluminum and 3 prominent cavity defects, the largest covering 781 µm2. Reusable DNMs are widely used in cataract surgery. Sharp carbon- or aluminum-containing burrs were detected on all reused instruments analyzed together with 1 burr of mixed composition, originating from (1) organic residues, (2) instrument fragments, or (3) salt and contaminant deposits. Sharp defects may contribute to capsular damage including PCR, and residues may pose other safety concerns. Therefore, we support development of a quality, reliable single-use alternative instrument and further encourage careful inspection of all reusable instruments principally by finger-tip interrogation for sharp edges preuse.

One-Piece Frontoorbital Osteotomy With a Small Supraorbital Burr-Hole to Protect Against Intraoperative Dural Lacerations.

This paper aims to describe a new technique of 1-piece frontoorbital osteotomy with a small supraorbital burr hole, which resulted in improved safety during osteotomy of the anterior skull base. An 11 × 4 mm burr hole was created at the center of the orbit above the superior orbital rim using an "eyebrow key-window approach." Extradural dissection from the nasion to the medial side of the sphenoid ridge was performed through this hole, and dissection of the lateral side of the sphenoid ridge was completed from the edge of the coronal osteotomy. Osteotomy along the zygomaticofrontal and sphenofrontal sutures were performed using an oscillating saw with secure protection of the dura. Between December 2019 and June 2020, 3 patients with unilateral coronal craniosynostosis underwent 1-piece frontoorbital advancement with the eyebrow key-window approach. The median age was 11 months (8-15 months), median operation time was 249 minutes (244-255 minutes), and the average blood transfusion was 10.8 ml/kg (0-18 ml/kg). No complications were observed, and the technique was associated with improved safety of osteotomy around the anterior skull base for 1-piece frontoorbital advancement.

Burr Hole Microsurgery for Middle Cerebral Artery Aneurysms: A Clinical Case Series

BACKGROUND: Minimally invasive microsurgery has become popular in neurosurgery. Burr hole microsurgery is another more modern minimally invasive technique that allows surgical treatment of various intracranial pathologies through an extreme small craniotomy. This article presents the first application of the burr hole approach for microsurgical clipping of cerebral aneurysms. OBJECTIVE: To assess the feasibility and outcomes of using the burr hole microsurgical technique in cerebral aneurysm surgery. METHODS: From March 2020 to August 2020, 3 patients with unruptured middle cerebral artery aneurysms underwent burr hole microsurgical clipping. RESULTS: Three patients with middle cerebral bifurcation aneurysms were successfully treated. The duration of surgery was from 62 to 83 min (median 72.5). Postoperatively, no new neurological symptoms, complications, or mortality were observed in all the cases. CONCLUSION: Burr hole microsurgery is an advanced neurosurgical method. Although the surgery is performed through a small burr hole approximately 14 mm in size, safe and successful treatment of normal-sized middle cerebral artery aneurysms using standard microsurgical principles and technique is possible.

Evaluating the Effectiveness of Minimally Invasive Surgery Using External Ventricular Drainage Systems in Draining Chronic Subdural Hematomas.

To show the effectiveness of minimally invasive surgery with external ventricular drainage systems (EVDS) in the treatment of chronic subdural hematomas by comparing with it with classic surgery with closed drainage system (CDS) with intracranial hematoma volume measurements and predict infection risks by comparing two different surgeries with each other with intracranial air volume measurements. From 2014 to 2020, the data of 28 patients with chronic subdural hematoma who underwent surgeries two large burr holes, saline irrigation, and CDS or one small burr hole, no saline irrigation, and EVDS were retrospectively who had preoperative computed tomography (CT) postoperative 1st-3rd day CT, and postoperative 7th-10th day CT were included in the study. Pre- and postoperative subdural liquid collection volumes and postoperative intracranial air volumes were measured using Sectra Medical Workstation. Results were compared between these two groups. There were no significant differences in the preoperative and 7th-10th day liquid volumes between these two groups (p > 0.05). There were significant differences in the postoperative 1st-3rd day air volume between these two groups (p < 0.001). The statistical results showed that surgeries with EVDS are as effective as surgeries with CDS in draining chronic subdural hematomas. We also determined that the intracranial air volume is significantly less in surgeries with EVDS. For this reason, we believe that EVDS can reduce the risk of postoperative infection.

Minimally Invasive Interphalangeal Arthrodesis.

Distal interphalangeal joint fusion is usually the surgical treatment for primary or posttraumatic osteoarthrosis when conservative measures fail. All fusion techniques aim for solid fusion with joint chondral resection, bone to bone contact and stable fixation in an adequate position. This is performed with an open dorsal approach considering the risks of soft tissue complications. We describe a technique of resecting bone cartilage and getting stable fixation with 2 mini incisions, 1 lateral and 1 in the digital pulp. Using a digital block anesthesia and under fluoroscopy, a small round burr is introduced into the joint by a lateral joint line stab incision. The joint space is enlarged by manual traction on the finger. After adequate cartilage resection, good bone to bone contact in an adequate position is fixed with a cannulated Herbert screw inserted percutaneously by the finger pulp. We describe 4 cases operated with this technique, 3 for pain and 1 for esthetics. All 4 demonstrated good results and were satisfied. X-rays showed solid fusion in 8 to 12 weeks. There was one complication with skin burning because of the burr heating and the authors describe how to avoid it. Minimally invasive distal interphalangeal joint fusion is a simple, reproducible technique that maintains the important steps for a solid arthrodesis with the advantage of preserving the soft tissue envelope.

Investigation on the Exit Burr Formation in Micro Milling.

The burr on micro part has harmful effect on the dimensional accuracy and service performance. The original control of exit burr formation during micro milling is desirable and advisable. In this paper, the formation mechanism of exit burr was studied based on the varying cutting direction during micro milling. Three exit burr control strategies were concluded, the material properties embrittlement, the support stiffness increasing and machining parameter optimizing operations. Then, micro milling experiments were carried out to investigate the exit burr morphology and size. It was found that the exit burr formation was attributed to the change of material flowing path at the exit surface, which was caused by the negative shear deformation zone that was induced by the discontinuous shape features. Different exit burr morphologies were classified; the triangle exit burr type was caused by the varying exit burr growing direction along the exit surface. The optimal machining parameters in micro milling to obtain a small exit burr were suggested.

Investigation of Optimum Grinding Condition Using cBN Electroplated End-Mill for CFRP Machining

Recently, carbon fiber reinforced plastics (CFRP) have been used in various applications such as airplanes and automobiles. In CFRP molding, there are unnecessary portions on the outer area. Therefore, a machining process is required to remove them. Cutting and grinding are conventionally used in the finish machining of CFRPs. End-milling allows the removal of most of these portions. However, uncut fibers easily occur during end-milling. In contrast, a precise machined surface and edge are easily obtained using a grinding tool. Therefore, this research has developed a novel cubic boron nitride (cBN) electroplated end-mill that combines an end-mill and a grinding tool. This is a versatile tool that can cut and grind CFRPs by changing the direction of rotation of the tool. In this study, the effectiveness of the developed tool is investigated. First, the developed tool machined the CFRP by side milling. Consequently, cBN abrasives that were fixed on the outer surface of the developed tool did not detach in certain cutting conditions. Next, in order to generate a sharp edge on the CFRP and restrict the increase in the CFRP temperature with the cBN electroplated end-mill, the optimum abrasive size and grinding condition were investigated through the design of experiments. Moreover, the effectiveness of the developed tool was verified by comparing it with a conventional tool. As a result, smaller burrs and uncut fibers were observed after final machining with the developed tool under the derived optimum condition than those with conventional tools. However, the desired surface roughness could not be achieved as required by the airline industry. Therefore, oscillating grinding was applied. In addition, the formula of the theoretical surface roughness while using the developed tool was derived using the theory of slant grinding. As a result, the oscillating condition that led to the required surface roughness was obtained by theoretical analysis. In addition, the required value for the airline industry was achieved by oscillating grinding.

Complete intracranial migration of ventriculoperitoneal shunt-a rare complication

Background: Ventriculoperitoneal shunt (VPS) is one of the most common procedures for the treatment of hydrocephalus. However, there are a number of complications associated with it. Case Presentation: We aim to present a rare complication of complete intraventricular migration of the VPS system. Our patient was a 12-month-old child who presented 8 months following placement of a right VPS for congenital hydrocephalus. He complained of progressive enlargement of head and vomiting. Examination did not reveal any palpable shunt under the skin on head, neck, or torso. An X-ray showed the presence of the complete shunt coiled within the ventricles. The shunt was removed endoscopically and third ventriculostomy was performed. Conclusion: Complete intracranial migration of VPS is a rare complication and can be avoided by making a small burr hole and careful anchoring of shunt. Trans-cranial endoscope is a useful tool for retrieval in such case and avoid more invasive procedure.

Mekanisme Pembentukan Burr pada Pemesinan Frais Mikro Ti 6Al- 4V ELI dalam Keadaan Kering

One of the ingredients that are popular now is titanium, but titanium is a material that is difficult to process using conventional milling machining because of the poor thermal conductivity of the material so that the high-temperature machining process produced in the cutting zone causes plastic deformation in cutting tools and increased chemical reactivity in titanium. High-speed micro-milling machining can be used for micromachining of hard metals or alloys that are difficult to achieve at low speeds. Micro milling machining in titanium material 6Al-4V ELI with variations in milling knife diameter 1 and 2 mm, spindle speed 10.000 and 15.000 rpm, feed 0,001 and 0,005 mm / rev, depth of cut 100 and 150 μm, which then do data processing using the method Taguchi full factorial and theoretical analysis. The results showed that the diameter of the tool and into the cut had the greatest effect on burr formation, the greater the diameter of the milling blade resulted in the formation of shorter and smaller burrs, the use of a 1 mm diameter milling blade and a 150 μm depth cut gave rise to long burr formations and tight, while the use of a 2 mm diameter milling blade and a cutting depth of 100 μm give rise to a short and slight burr formation.

Early Implementation of Veno-Venous Hemofiltration and Use of Rotational Atherectomy in a Patient with ST-Elevation Myocardial Infarction Complicated by Cardiogenic Shock: A Case Report

Background: We report the case of a patient with Cardiogenic Shock (CS) in a course of acute Right Ventricular (RV) Myocardial Infarction (MI) following occlusion of the proximal Right Coronary Artery (RCA). Our case highlights the use of Continuous Veno-Venous Hemofiltration (CVVH) as a novel routine treatment option for Acute Kidney Injury (AKI) in the setting of CS and the use of Rotational Atherectomy (RA) in patients with MI. This finding has important implications for patient treatment plans in the future. Case summary: The patient was treated with the primary Percutaneous Coronary Intervention (PCI) using three drug-eluting stents in the main RCA and strong right ventricular branch. RA was used to facilitate lesion expansion and stent implantation because of massive calcification. Six hours after the procedure, AKI manifested as anuria, required CVVH for four days until hemodynamic stabilization and restoration of diuresis. Six weeks after MI, the patient underwent coronary artery bypass surgery due to advanced coronary disease in the left coronary artery. There were no peri-or post-procedural complications, and at the end of a cardiac rehabilitation program, the patient was discharged. Conclusion: RA of calcifications in the infarct-related artery may remain the only option for delivering a stent, and thus maintain patency of the supplied coronary vessel, which is essential for hemodynamically unstable patients. RA can be a safe option if extreme precautions like using small burr sizes and low speeds are used. CVVH may be the first-choice option in patients otherwise treated with RV mechanical circulatory support.

Analisa Pengaruh Variasi Parameter Gurdi (Drilling) Dan Pendingin Terhadap Burr Formation Hasil Pemesinan Cnc Routermilling Pada Aluminium Sheet 1100

In the machining process, one of the things that cannot be released is the occurrence of burr formation or chip that sticks to the moment after the deduction process is carried out. To reduce burr formation is usually by determining good cutting parameters and given a cooling medium that functions to control the temperature during lubrication.This study aims to determine the burr formation on the 1100 aluminum sheet material using the machining method of milling raouter with the depth of feeding in accordance with the thickness of the workpiece. The spindle rotation used is 1200 rpm with a variation of the cutting tool eyes that is 4 mm, 6 mm, and 8 mm of the HSS tool brand and variations of the cooler namely air, coolant, oil. This research uses taguchi and ANOVA methods by measuring burr formation using USB microscope with 1200 x magnification. Then get the smallest burr formation value of 0.16819 mm with the parameter arrangement of the diameter of the drill bit 6, (f) 40 mm / minute, oil coolant. As for the Exit (outlet) the smallest burr formation of 0.27211 mm in the arrangement of the diameter of the tool diameter of the 4, (f) 50 mm / minute oil cooler.