Abrasive Waterjet Machining.

The abrasive waterjet machining process was introduced in the 1980s as a new cutting tool; the process has the ability to cut almost any material. Currently, the AWJ process is used in many world-class factories, producing parts for use in daily life. A description of this process and its influencing parameters are first presented in this paper, along with process models for the AWJ tool itself and also for the jet-material interaction. The AWJ material removal process occurs through the high-velocity impact of abrasive particles, whose tips micromachine the material at the microscopic scale, with no thermal or mechanical adverse effects. The macro-characteristics of the cut surface, such as its taper, trailback, and waviness, are discussed, along with methods of improving the geometrical accuracy of the cut parts using these attributes. For example, dynamic angular compensation is used to correct for the taper and undercut in shape cutting. The surface finish is controlled by the cutting speed, hydraulic, and abrasive parameters using software and process models built into the controllers of CNC machines. In addition to shape cutting, edge trimming is presented, with a focus on the carbon fiber composites used in aircraft and automotive structures, where special AWJ tools and manipulators are used. Examples of the precision cutting of microelectronic and solar cell parts are discussed to describe the special techniques that are used, such as machine vision and vacuum-assist, which have been found to be essential to the integrity and accuracy of cut parts. The use of the AWJ machining process was extended to other applications, such as drilling, boring, milling, turning, and surface modification, which are presented in this paper as actual industrial applications. To demonstrate the versatility of the AWJ machining process, the data in this paper were selected to cover a wide range of materials, such as metal, glass, composites, and ceramics, and also a wide range of thicknesses, from 1 mm to 600 mm. The trends of Industry 4.0 and 5.0, AI, and IoT are also presented.

Anterior Sagittal Anorectoplasty with External Sphincter Preservation for the Treatment of Recto-vestibular Fistula: A New Approach.

CONTEXT: To our knowledge, there is no description of anterior sagittal anorectoplasty (ASARP) with external anal sphincter preservation and passing neorectum in the middle of muscle complex under direct vision for the treatment of recto-vestibular fistula (VF). AIM: This study evaluates a new modification combining ASARP with under vision sphincter preservation. SUBJECTS AND METHODS: This prospective study was conducted on thirty female infants with VF. Procedure starts with a vertical midline incision extending from ectopic opening to posterior limit of external sphincter. Sharp dissection of the fistula is carried out. Artery forceps is passed at the center of muscle complex under vision, then neorectum is placed in the middle of the muscle complex. We introduced a new scoring system based on parental interview assessing functional outcome. Each patient was given a score between 0 and 20; good: 14-20, fair: 7-13, and poor: 0-6. RESULTS: ASARP was performed at a mean age of 2.6 months, a mean weight of 5.2 kg, a mean operative time of 102 min, and a mean hospital stay of 3.6 days. Wound infection occurred in four cases, seven cases had perianal excoriations, six cases had anal stenosis, and only one case complained of anal displacement. Patients followed for a mean of 18.8 months. Majority of our patients (50%) had good score (mean = 16.8), normal frequency, no or mild soiling, normal anal position with no or mild stenosis. Fourteen patients had fair score (mean = 10.5). Only one had poor outcome with severe soiling and perineal excoriation. CONCLUSION: Our modification offers optimal correction, with minimal sphincteric damage, without additional complexity or difficulties. Scoring system is simple, practical, and truly reflects early functional and parent satisfaction after surgery.

Laparoscopy in the management of impalpable testis (Series of 64 Cases).

BACKGROUND: The undescended testis represents one of the most common disorders of childhood. Laparoscopy has been widely used both in the diagnosis and treatment of non-palpable testis. In this study, we investigated and evaluated the usefulness of laparoscopy in the diagnosis and treatment of no palpable testis. PATIENTS AND METHODS: From January 2003 to January 2008, we used laparoscopy in the management of 64 patients with 75 impalpable testes. Their ages varied from 1 to 15 years (median age = 4.6 years). The site and the size of the testes were localised by abdominopelvic ultrasonography in all 64 children for accurate diagnosis. One stage laparoscopic orchiopexy was performed in 26 testes, staged Fowler-Stephens orchiopexy was underwent in 17 testes, while laparoscopic orchidectomy was done in 5 testes. Follow-up by clinical examination and colour Doppler ultrasound was performed in every patient who underwent orchiopexy. RESULTS: There were 11 patients with bilateral non-palpable testes. The overall diagnostic agreement of ultrasound with laparoscopy was seen in only 16 out of 75 testes (21.3%). The results of diagnostic laparoscopy were varied and showed various pathological. Conditions and positioned of the testes, such as 20 low intra-abdominal testes (26.6%), 17 testes were high intra-abdominal (22.7%), and 18 testes (24%) entered the inguinal canal. Associated inguinal hernia was present in 4 patients. After a mean follow-up period of 26 months (6 months - 5 years), all testes were in the bottom of the scrotum except 3 testes were retracted to the neck of the scrotum and atrophy of the testis occurred in 2 patients (2.7%). CONCLUSION: Laparoscopy has proven to be the only diagnostic modality where the findings provide a clear dependable direction for the definitive management of impalpable testes, so it allows an accurate diagnosis and definitive treatment in the same sitting.

Effects of lornoxicam on the hemodynamic and catecholamine response to laryngoscopy and tracheal intubation.

BACKGROUND AND OBJECTIVES: Laryngoscopy and tracheal intubation are associated with hemodynamic responses that might increase morbidity and mortality in some patients. Lornoxicam is a nonsteroidal anti-inflammatory drug, which, when added to fentanyl, successfully attenuated the pressor response of intubation. The aim of this study was to evaluate the effect of lornoxicam on the hemodynamic response and serum catecholamine levels following laryngoscopy and tracheal intubation. METHODS: Fifty adult patients scheduled for general anaesthesia with endotracheal intubation were enrolled in this randomized, double-blind placebo-controlled study. They were divided into two equal groups to receive intravenously either lornoxicam 16 mg or placebo 30 min before surgery. Mean arterial pressure and heart rate were recorded before and after induction of anaesthesia, and every minute after intubation for 10 min. Serum catecholamine levels were measured before induction and 1 min after intubation. RESULTS: After induction, there was a significant decrease in blood pressure in both groups. In the first 3 min after tracheal intubation, a significant increase in the hemodynamic parameters and in the serum norepinephrine level was observed in the control group. CONCLUSION: Lornoxicam 16 mg attenuates the pressor response to laryngoscopy and intubation of the trachea.

Successful implantation of physiologically functional bioengineered mouse internal anal sphincter.

We have previously developed bioengineered three-dimensional internal anal sphincter (IAS) rings from circular smooth muscle cells isolated from rabbit and human IAS. We provide proof of concept that bioengineered mouse IAS rings are neovascularized upon implantation into mice of the same strain and maintain concentric smooth muscle alignment, phenotype, and IAS functionality. Rings were bioengineered by using smooth muscle cells from the IAS of C57BL/6J mice. Bioengineered mouse IAS rings were implanted subcutaneously on the dorsum of C57BL/6J mice along with a microosmotic pump delivering fibroblast growth factor-2. The mice remained healthy during the period of implantation, showing no external signs of rejection. Mice were killed 28 days postsurgery and implanted IAS rings were harvested. IAS rings showed muscle attachment, neovascularization, healthy color, and no external signs of infection or inflammation. Assessment of force generation on harvested IAS rings showed the following: 1) spontaneous basal tone was generated in the absence of external stimulation; 2) basal tone was relaxed by vasoactive intestinal peptide, nitric oxide donor, and nifedipine; 3) acetylcholine and phorbol dibutyrate elicited rapid-rising, dose-dependent, sustained contractions repeatedly over 30 min without signs of muscle fatigue; and 4) magnitudes of potassium chloride-induced contractions were 100% of peak maximal agonist-induced contractions. Our preliminary results confirm the proof of concept that bioengineered rings are neovascularized upon implantation. Harvested rings maintain smooth muscle alignment and phenotype. Our physiological studies confirm that implanted rings maintain 1) overall IAS physiology and develop basal tone, 2) integrity of membrane ionic characteristics, and 3) integrity of membrane associated intracellular signaling transduction pathways for contraction and relaxation by responding to cholinergic, nitrergic, and VIP-ergic stimulation. IAS smooth muscle tissue could thus be bioengineered for the purpose of implantation to serve as a potential graft therapy for dysfunctional internal anal sphincter in fecal incontinence.

Surgical implantation of a bioengineered internal anal sphincter.

PURPOSE: Fecal incontinence is a common disorder that can have devastating social and psychologic consequences. However, there are no long-term ideal solutions for such patients. Although loss of continence is multifactorial, the integrity of the internal anal sphincter (IAS) has particular significance. We previously described the development of 3-dimensional bioengineered constructs using isolated smooth muscle tissue from donor C57BL/6 IAS. We hypothesized that the bioengineered ring constructs would retain cellular viability and promote neovascularization upon implantation into a recipient mouse. METHODS: Internal anal sphincter ring constructs were surgically implanted into the subcutaneous tissue of syngeneic C57BL/6 mice and treated with either fibroblastic growth factor 2 (0.26 microg daily) or saline controls using a microosmotic pump. Internal anal sphincter constructs were harvested after 25 days (range, 23-26 days) and assessed morphologically and for tissue viability. RESULT: Gross morphology showed that there was no rejection. Rings showed muscle attachment to the back of the mouse with no sign of inflammation. Fibroblastic growth factor 2 infusion resulted in a significantly improved histologic score and muscle viability compared with the control group. CONCLUSIONS: Three-dimensional bioengineered IAS rings can be successfully implanted into the subcutaneous tissue of recipient mice. The addition of fibroblastic growth factor 2 led to improved muscle viability, vascularity, and survival. This approach may become a feasible option for patients with fecal incontinence.

Long-term functional outcome and quality of life in patients with high imperforate anus.

PURPOSE: Anorectal malformations (ARMs) are associated with a large number of functional sequale that may affect a child's long-term quality of life (QOL). The purposes of this study were to better quantify patient functional stooling outcome and to identify how these outcomes related to the QOL in patients with high imperforate anus. METHODS: Forty-eight patients from 2 children's hospitals underwent scoring of stooling after 4 years of life. Scoring consisted of a 13-item questionnaire to assess long-term stooling habits (score range: 0-30, worst to best). These results were then correlated with a QOL survey as judged by a parent or guardian. RESULT: Mean (SD) age at survey was 6.5 (1.6) years. Comparison of QOL and clinical scoring showed no signficant difference between the 2 institutions (P > .05). There was a direct correlation between the QOL and stooling score (Pearson r(2) = 0.827; beta coefficient = 24.7, P < .001). Interestingly, functional stooling scores worsened with increasing age (Pearson r(2) = 0.318, P = .02). Patients with associated congenital anomalies had a high rate of poor QOL (44% in poor range; P = .001). Stooling scores decreased significantly with increasing severity/complexity of the ARM (P = .001). CONCLUSION: A large number of children experience functional stooling problems, and these were directly associated with poor QOL. In contrast to previous perceptions, our study showed that stooling patterns are perceived to worsen with age. This suggests that children with ARMs need long-term follow-up and counseling.

Laparoscopy in the management of impalpable testis: series of 64 cases.

BACKGROUND: The undescended testis represents one of the most common disorders of childhood. Laparoscopy has been widely used for the diagnosis and treatment of non-palpable testis. In this study, we investigated and evaluated the usefulness of laparoscopy in the diagnosis and treatment of the non-palpable testis. METHODS: From January 2003 to January 2008, we used laparoscopy in the management of 64 patients with 75 impalpable testes. The patients' ages varied from 1 to 15 years (median 4.6 years). The sites and sizes of the testes were localized by abdominopelvic ultrasonography (US) in all 64 children. One-stage laparoscopic orchiopexy was performed for 26 testes, staged Fowler Stephens orchiopexy for 17 testes, and laparoscopic orchidectomy for five testes. Follow-up by clinical examination and color Doppler US was performed in every patient who underwent orchiopexy. RESULTS: There were 11 patients with bilateral non-palpable testes. The overall diagnostic agreement of US with laparoscopy was seen for only 16 of 75 testes (21.3%). The results of diagnostic laparoscopy were varied and showed various pathologic conditions and positions of the testes, such as 20 low intraabdominal testes (26.6%), 17 high intraabdominal testes (22.7%), and 18 testes (24%) that had entered the inguinal canal. Associated inguinal hernia was present in four patients. After a mean follow-up period of 26 months (6 months-5 years) all testes were seen to be located in the bottom of the scrotum, with the exception of three testes that had retracted to the neck of the scrotum and two testes that had atrophied (2.7%). CONCLUSIONS: Laparoscopy has proven to be the only diagnostic modality where the findings provide a clear, dependable direction for definitive management of impalpable testes. It allows an accurate diagnosis and simultaneous definitive treatment.

Outcome of the rhomboid flap for recurrent pilonidal disease.

BACKGROUND: Pilonidal sinus is a common chronic disease of the sacrococcygeal region. Treatment varies according to the clinical presentation of the disease. Although many surgical methods have been suggested, an ideal method is still lacking because of high recurrence rates. Recurrent disease causes significant morbidity, particularly missing time from work. The aim of this study was to assess the rhomboid flap's role in promoting primary healing in recurrent pilonidal disease and to evaluate morbidity and recurrence. METHODS: This prospective study included 60 patients who were treated with the use of a rhomboid flap closure for recurrent sacrococcygeal pilonidal sinus at Tanta University Hospital, Egypt, from January 2000 to October 2006. The follow-up period ranged from 6 months to 7 years, with the mean follow-up period about 2.5 years. RESULTS: There were 46 males and 14 females with a median age of 18 years (range = 16-38 years). The mean hospital stay was 6 days (range = 5-11 days). Four patients had to be hospitalized for 1-2 weeks due to superficial wound infection; they recovered with injected antibiotics. The mean time to return to work after discharge from the hospital was 15 days (range = 12-26 days). Postoperative morbidity involved superficial wound infection in 9 patients (15%). There were six recurrences (10%). Eleven patients (18.3%) had numbness over the flap and 12 patients (20%) were not pleased with the cosmetic appearance of the scars. CONCLUSIONS: Our study favors the rhomboid flap for recurrent sacrococcygeal pilonidal sinus, especially for complex sinuses, and found it suitable for cases where simpler operations have failed. It allows early return to full activity, does not necessitate prolonged postoperative care, and has very low recurrence and complications rates which may outweigh the disadvantages related to an unfavorable cosmetic appearance.

Renal dysplasia with extrarenal calyces.

We describe a case of simple renal dysplasia with extrarenal calyces of the left kidney in a 2-year-old boy. Other anomalies also included pelviureteral junction obstruction and ectopic ureterocele on the same side, as well as grade V vesico-ureteral reflux on the opposite side.