Metal Cannula Research Articles

Comparison of i.v. cannula and Stevens’ cannula for sub-Tenon’s block

Sub-Tenon's local anaesthesia (STLA) is growing in popularity for ophthalmic surgery, and is widely regarded as safer than the alternative sharp needle techniques. Although safe, STLA is not devoid of risk. Therefore, the effectiveness of a plastic i.v. cannula was compared with the traditional metal Stevens' cannula for delivering STLA. In a randomized, controlled trial, the efficacy of STLA administered by either a Stevens' sub-Tenon's metal cannula or a standard 20 G Optiva i.v. plastic cannula was compared; 120 patients, undergoing cataract surgery, were randomly allocated to one of the two groups. After STLA, the primary outcome measure, kinesia of the globe, was recorded at 5 and 10 min. There was no significant difference in the mean total ocular movement scores after STLA performed by either the 20 G i.v. cannula or standard 19 G sub-Tenon's cannula (P = 0.10). There was also no significant difference in any of the secondary outcome measures. A 20 G Optiva i.v. cannula and the Stevens' sub-Tenon's cannula were equally effective at providing STLA.

Reduction of iatrogenic RPE lesions in AMD patients: evidence for wound healing?

Our purpose was to study retinal pigment epithelium (RPE) wound healing in patients with age-related macular degeneration (AMD). Abrasive debridement of nasal RPE was performed with a metal cannula during pars plana vitrectomy for foveal choroidal neovascularization (CNV) membrane excision combined with simultaneous autologous RPE transplantation. Fundus autofluorescence, fluorescein angiography images, and red-free pictures were taken initially within 1-2 weeks postoperatively, subsequently in 2-week intervals until 3 months, monthly until 6 months, and every 3 months thereafter. The borders of these lesions were measured; areas were calculated and compared using ArchiCad Software. Fourteen eyes of 14 patients suffering from AMD were included (nine women and four men, mean age 75.6 years +/-6.6 years). Six of 14 (42.9 %) patients showed a reduction of the RPE debrided area. The size of these lesions reduced 5.6-20% within 2 postoperative months compared with their size at first examination (from a mean of 13.7 mm2 +/- 7.2 at baseline to a mean of 12.8 mm2 +/- 6.7 at 2 months postoperatively). No further reduction of the lesions was seen after the 2 months. In eight cases, borders of the RPE debrided areas stayed stable during observation time. Wound healing of abrasively debrided RPE monolayer defects in patients with AMD occurs to a certain extent in nearly half of the cases. This process seems to stop after 2 months.

Laparoscopic Placement of Ventriculoperitoneal Shunts: An Innovative Simplification of the Existing Techniques

Ventriculoperitoneal shunting (VPS) remains one of the alternative choices for the surgical treatment of hydrocephalus. During the last two decades laparoscopy has been utilized to facilitate the placement of the abdominal portion of the shunt. We describe a minimally invasive laparoscopic technique, which facilitates the rapid, safe and direct placement of the peritoneal component of the VPS. A side frontal ventricular catheter is placed through a small burr hole and connected to the valve at the postauricular region. An infra-umbilical trocar is placed, using the Hasson technique, and after the pneumoperitoneum is established, a 10-mm laparoscope is introduced for identification of a VPS entry side free of adhesions. A 5-mm skin incision is made at the decided point of catheter insertion, usually at the right upper quadrant. Using a tunneler, the VPS catheter is placed subcutaneously from abdomen insertion point, to the postauricular region, where it is connected to the valve. A split type, 10-12 Fr and 12-15 cm long metallic puncture cannula, like those used for suprapelvic percutaneous bladder drainage, is introduced into the abdomen. Under direct laparoscopic vision the peritoneal portion of the VPS is passed into the abdomen through the cannula. The catheter is leaded to a desirable location by pointing the needle accordingly. Alteration of the position of the catheter can also be attained by entraining the catheter with the laparoscope and without using auxiliary graspers. The function of the VPS is confirmed under direct visualization. Suturing the abdominal and cranial incisions completes the procedure. We used this technique in a series of 12 patients with excellent outcome. There were no intra- or postoperative complications and no mortalities. Our technique is less invasive than a minilaparotomy, embraces all laparoscopic benefits and does not require auxiliary forceps or guidewires. It uses easy available materials with low cost, and attains an easy, rapid, and safe placement of the abdominal portion of the VPS.

Synechia vulvae – an unusual cause of urinary symptoms in a 15‐year‐old girl

Synechia vulvae (adhesions of the labia minora) are characterized by a complete or partial fusion of the labia minora in the midline. In the majority of cases, vulvae adhesion causes no symptoms but occasionally it can cause urinary infections and difficulties in micturition. It is usually observed within the first 2 years of life (1). A girl, aged 15, menarche aged 13, cycle 7/5–6 weeks, and virgin, was admitted to hospital, because she had difficulties in micturition. During micturition, she had to use two fingers against the perineum to urinate, otherwise only drops came out. She also had the feeling of something filling in her vagina at the size of a tennis ball. Micturition was prolonged (10–15 min). She felt that she was urinating through vagina. After micturition, there was continuous urinary leak. The symptoms increased during menstruation, because blood and tissue clotted the little opening in the perineum. The symptoms started 6 months prior to her admittance to our department. During these 6 months, she was more and more disabled. She drank as little as possible to avoid micturition. She urinated three to four times per day. No nycturia was examined. Her mother confirmed that there had not been symptoms earlier and no history regarding infections. She had never noticed the synechia vulvae during her daughter's childhood. Gynecologic examination revealed a membrane at the vaginal orifice, but neither the introitus nor the urethral opening could be visualized. There was a small opening where urine could pass through (Figure 1). Abdominal ultrasound showed normal uterus and normal ovaries. Residual urine volume was 40 ml. The ultrasound examination of the kidneys was normal. Urine examination showed no bacterial growth on culture. Metal cannula inserted into the existing vulvar opening during surgery. Under general anesthesia, the obstructing vaginal membrane was incised. The two edges were sutured to prevent a new agglutination (Figure 2). Inspection showed a normal vagina, although it was deep and wide. The portio was normal. The uterus was normal in size and anteverted by exploration. She was instructed to wash the external genitalia after micturition and use lidocaine ointment, if she needed to. After lysis of synechia vulvae. After 2 months follow up, gynecologic examination showed a normal introitus of the vagina and no agglutination had occurred. She had no difficulties in micturition. It has not been proved possible to obtain any concrete figures for the incidence of synechia vulvae. The majority of authors state that it occurs quite frequently (1–4). This case differs from former cases, because the patient was 15 years old when she came to our department with her symptoms. In the previous literature, the condition has been described in girls aged from 6 months to 7 years (1). The condition has been recognized for a long time (5), but in recent years, it has only had superficial mention (1, 6). In the discussion on the etiology of synechia vulvae, the majority of authors consider the condition as acquired. The pathogen-esis is not known, but there have been several theories: inflammation of the mucous membrane of the labia resulting from poor hygiene, vulvitis or mechanical irritation, a certain mucilaginous property, due to an exaggeration of the normal hypoestrogenism of childhood (1, 3), (5, 7). In this particular case, we know there had not been any former infections, and according to the mother, the condition must be acquired because she had not noticed the synechia vulvae in early childhood. The condition may disappear spontaneously (3, 5), (7). No treatment is necessary in most cases, and only complete or extensive partial synechia and cases causing symptoms and urinary infections should be treated. The treatment is very simple. The membrane should be divided in the midline either by manual traction in local or without anesthesia or incised under general anesthesia (1, 7). Application of ointment prevents any further adhesion. The division of the labia minora usually reveals normal external genitalia and normal vagina.

Submandibular sialogram performed through a Wharton's duct fistula: Technical adaptation of conventional technique

We report a case of submandibular duct fistula in which a sialogram was performed through the fistulous opening after attempt of sialography through the Wharton's duct had failed. To our knowledge, this technical modification in obtaining a sialogram has not been described previously in scientific literature. Blunt-tipped needles and polythene catheters are commonly used for cannulation of the submandibular duct orifice for obtaining a sialogram. However, in this case, a larger gauge metallic cannula was employed to opacify the ductal system through the fistula.

Evaluation of Pain in Three Hysterosalpingography Techniques: Metal Cannula With and Without Paracervical Blockage and Balloon Catheter

The objective of this study was to assess discomfort or pain in patients undergoing hysterosalpingography using three different techniques. Eighty-nine patients were randomly assigned to one of three groups. In group 1, 30 patients underwent the technique performed with a metal cannula without anesthetic; in group 2, 29 patients underwent the technique performed with a metal cannula with previous paracervical anesthetic block; in group 3, 30 patients submitted to the procedure performed with a flexible balloon catheter. Each patient completed two questionnaires, Q1 and Q2: Q1 assessed their personal, clinical, and surgical history, and Q2 provided the visual analog scale (VAS) for pain assessment. The investigator also evaluated discomfort at each potentially painful stage of the procedure based on the patient's verbal expression, physical manifestations, or both. In terms of global discomfort experienced during hysterosalpingography, group 1 had the highest mean VAS score, whereas scores did not significantly differ between groups 2 and 3. During cervical grasping, group 2 experienced less discomfort than group 1. A comparison of pain associated with cervical grasping and balloon inflation (group 3 only) revealed that the highest levels of discomfort occurred during cervical grasping without anesthesia (group 1), followed by balloon inflation inside the cervix (group 3), and, last, cervical grasping after paracervical block (group 2). Performing hysterosalpingography with a flexible balloon catheter or metal cannula with previous paracervical block produced similar levels of pain; however, both techniques appear to be more comfortable than the traditional technique (i.e., metal cannula without anesthesia).

Transhepatic Puncture of Portal and Hepatic Veins for TIPS Using a Single-Needle Pass Under Sonographic Guidance

Creating transjugular intrahepatic portosystemic shunts (TIPS) requires accessing a portal vein branch from a metal cannula wedged in a hepatic vein. This initial step in shunt creation often requires multiple blind intrahepatic punctures and occasionally fails. We describe a method using sonographic guidance to serially puncture the portal vein and hepatic vein with a single transhepatic needle pass, after which the TIPS procedure is completed in the standard transjugular fashion. Sonographically guided transhepatic dual puncture of the portal and hepatic veins facilitates portosystemic shunt creation in a single needle pass and allows more controlled selection of the portal vein entry and hepatic vein landing sites in selected patients.

Transjugular liver biopsy: prospective evaluation of the angle formed between the hepatic veins and the vena cava main axis and modification of a semi-automated biopsy device in cases of an unfavorable angle

In cases of transjugular liver biopsies, the venous angle formed between the chosen hepatic vein and the vena cava main axis in a frontal plane can be large, leading to technical difficulties. In a prospective study including 139 consecutive patients who underwent transjugular liver biopsy using the Quick-Core biopsy set, the mean venous angle was equal to 49.6 degrees. For 21.1% of the patients, two attempts at hepatic venous catheterization failed because the venous angle was too large, with a mean of 69.7 degrees. In all of these patients, manual reshaping of the distal curvature of the stiffening metallic cannula, by forming a new mean angle equal to 48 degrees , allowed successful completion of the procedure in less than 10 min.

Differential Expression Profiling of the Hepatic Proteome in a Rat Model of Dioxin Resistance

One characteristic feature of acute 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity is dramatic interspecies and interstrain variability in sensitivity. This complicates dioxin risk assessment for humans. However, this variability also provides a means of characterizing mechanisms of dioxin toxicity. Long-Evans (Turku/AB) rats are orders of magnitude more susceptible to TCDD lethality than Han/Wistar (Kuopio) rats, and this difference constitutes a very useful model for identifying mechanisms of dioxin toxicity. We adopted a proteomic approach to identify the differential effects of TCDD exposure on liver protein expression in Han/Wistar rats as compared with Long-Evans rats. This allows determination of which, if any, protein markers are indicative of differences in dioxin susceptibility and/or responsible for conferring resistance. Differential protein expression in total liver protein was assessed using two-dimensional gel electrophoresis, computerized gel image analysis, in-gel digestion, and mass spectrometry. We observed significant changes in the abundance of several proteins, which fall into three general classes: (i) TCDD-independent and exclusively strain-specific (e.g. isoforms of the protein-disulfide isomerase A3, regucalcin, and agmatine ureohydrolase); (ii) strain-independent and only dependent on TCDD exposure (e.g. aldehyde dehydrogenase 3A1 and rat selenium-binding protein 2); (iii) dependent on both TCDD exposure and strain (e.g. oxidative stress-related proteins, apoptosis-inducing factor, and MAWD-binding protein). By integrating transcriptomic (microarray) data and genomic data (computational search of regulatory elements), we found that protein expression levels were mainly controlled at the level of transcription. These results reveal, for the first time, a subset of hepatic proteins that are differentially regulated in response to TCDD in a strain-specific manner. Some of these differential responses may play a role in establishing the major differences in TCDD response between these two strains of rats. As such, our work is expected to lead to new insights into the mechanism of TCDD toxicity and resistance.

Use of a metal cannula for peroperative cholangiography

Use of a metal cannula for peroperative cholangiography

Use of a metal cannula for peroperative cholangiography

Use of a metal cannula for peroperative cholangiography

A novel applicator for the selective painting of pre-retinal structures during vitreoretinal surgery

To demonstrate a novel applicator, the so-called vitreoretinal-internal limiting membrane colour enhancer to achieve the selective painting of pre-retinal structures. The VINCE is a modified backflush needle, containing an adjustable silicone tube, which is surrounded by a metal cannula. The tube is connected to a dye container in the handpiece of the applicator. The instrument was successful in painting the retinal surface sufficiently and was found to be particularly useful to avoid unintended staining of the peripheral or foveal retina. The newly developed customized cartridge-loading system contains the ready prepared dye, avoiding time-consuming dilution and preparation of the vital dye during surgery in the OR. The VINCE is effective in restricting the dye only to the area of surgical interest. The VINCE is a useful tool to limit intraocular dye to the required area to minimize possible side effects to intraocular retinal structures.

Sub-Tenon's block with an ultrashort cannula

Purpose: To evaluate the effectiveness and safety of an orbital block using an ultrashort, wide-bore blunt metal cannula to inject local anesthetic agents into the anterior sub-Tenon's space. Setting: Department of Ophthalmology, North Riding Infirmary, Middlesbrough, United Kingdom. Methods: Fifty-nine consecutive patients having routine phacoemulsification with intraocular lens implantation were studied. Five milliliters of lidocaine 2% with adrenaline 1:200000 and hyaluronidase 150 units was injected into the anterior sub-Tenon's space in the inferonasal quadrant via a 16-gauge, short (0.6 cm), blunt metal cannula. Horizontal and vertical movements were assessed before injection and 2, 4, and 6 minutes after injection (also at 8 and 10 minutes if akinesia was inadequate). The movements were scored from 0 (no movement) to 3 (full movement). Incyclotorsion and lid movements were assessed at the same intervals. In the first 15 patients, B-scan ultrasonography was performed before, during, and 2 minutes after the injection. If the aggregate akinesia score was higher than 4 at 6 minutes, a supplementary injection was given. Pain during the injection and surgery was assessed using a 10-point verbal rating score. The incidence, severity, and quadrant of chemosis and conjunctival hemorrhage were noted. Results: Forty-eight patients (81.35%) had an aggregate akinesia score lower than 4 at 2 minutes and 58 (98.30%) at 4 minutes. One patient had an akinesia score higher than 4 at 6 minutes and required supplementary injection. Incyclotorsion was present in 42 patients (72.88%) at 2 minutes and in 19 (32.20%) at 4 minutes. Lid opening (levator function) was present in 33 patients (55.93%) at 2 minutes and in 19 (32.20%) at 4 minutes. Lid closure (orbicularis function) was present in 34 patients (57.62%) at 2 minutes and in 18 (30.50%) at 4 minutes. One patient required a supplementary injection at 10 minutes. Ultrasonography showed the injection caused rapid opening of sub-Tenon's space, with fluid spreading around the optic nerve. No pain on injection occurred in 67.79% of patients; 17 (28.81%) had a verbal rating score of 1, 1 (1.69%) had a score of 3, and 1 had a score of 5. No patient reported pain during surgery. A minor degree of chemosis and conjunctival hemorrhage occurred in 43 patients and 37 patients, respectively. Moderate chemosis occurred in 15 cases and severe chemosis in 1 case. Conclusions: Effective and predictable ocular anesthesia can be achieved using a blunt, ultrashort cannula for sub-Tenon's block. The technique greatly reduces the risks for globe perforation, muscle damage, and other serious complications.

Advances in Imaging Technology and the Growth of Vascular and Interventional Radiology: A Brief History

THE development of vascular and interventional radiology (IR) as a discipline or a set of patient-care techniques can be described from many viewpoints. One could study its pioneering and innovative physicians or assess how advances in catheters and other device-based technologies have influenced the course of vascular and IR. This article will focus on how imaging technology has shaped the discipline. The advent and subsequent evolution of the modern fluoroscopically based angiographic interventional suite enabled the development of early diagnostic angiography and subsequent interventions. Cross-sectional imaging techniques such as computerized axial tomography and real-time ultrasound (US) also enabled the development of specific interventions. These modalities have also had a profound influence on case selection and case mix and have helped catalyze the evolution of vascular and IR into an interventional specialty. The first iodine-based contrast arteriogram in a patient was reported in 1929 by Dos Santos (1), approximately 34 years after the discovery of the x ray (2) and almost simultaneously with the description of the first iodinated contrast medium (3). Without the benefit of fluoroscopy, a nonselective aortogram could be obtained only by a blind translumbar puncture advancing a stiff metallic cannula with use of surface anatomic landmarks. Filming consisted of a timed single radiographic exposure. Evolution of the translumbar technique was relatively glacial for three decades, probably for two reasons. First, there was no real push to develop it because there were few operative techniques for atherosclerotic occlusive disease or aneurysmal disease, and therefore there were few real indications for the procedure. Second, there was no practical imaging technique that allowed easy and effective visualization of catheter manipulation in real time.

A simple device for making a glove balloon for retroperitoneal dissection

Expansion of the retroperitoneal space is required prior to a retroperitoneal or an extraperitoneal laparoscopic procedure. This is usually performed by inflating a homemade glove balloon or a commercially available balloon. The latter is expensive and the former can sometimes be cumbersome. The present device is a metal cannula with a specially designed nut that holds the fingerstalls of a glove in position obviating the need for a tie. It was used in nine patients for three upper ureterolithotomies, three nephrectomies and three pyelolithotomies, all performed by the retroperitoneal laparoscopic approach. The fingerstalls did not burst or come off during inflation, the quality of dissection was satisfactory and all procedures were performed successfully. This simple reusable device provides a reliable and economical method for making a homemade balloon.

Autologous transplantation of retinal pigment epithelium after mechanical debridement of Bruch’s membrane

Purpose. To determine whether transplantation of autologous retinal pigment epithelium (RPE) will prevent atrophy of the choriocapillaris and loss of photoreceptors in an area in which the RPE has been mechanically debrided from Bruch’s membrane. Methods. Abrasive debridement of RPE was performed with a metal cannula after localized retinal bleb detachments in two separate areas of the rabbit retina. The RPE cell suspension aspirated from one of the debridement sites was transplanted to the other. The debridement-only site served as control. The transplant and control sites were evaluated after 30 days by color fundus photography, fluorescein angiography, light microscopy and transmission electron microscopy. Results. Compared with debridement only, debridement plus transplantation of RPE resulted in more complete repopulation of the bare Bruch’s membrane surface with relative preservation of chorioccapillaris and photoreceptors Conclusion. Autologous transplantation of RPE onto an abrasively debrided Bruch’s membrane decreases choriocapillaris atrophy and photoreceptor loss.

A simple device for making a glove balloon for retroperitoneal dissection

Expansion of the retroperitoneal space is required prior to a retroperitoneal or an extraperitoneal laparoscopic procedure. This is usually performed by inflating a homemade glove balloon or a commercially available balloon. The latter is expensive and the former can sometimes be cumbersome. The present device is a metal cannula with a specially designed nut that holds the fingerstalls of a glove in position obviating the need for a tie. It was used in nine patients for three upper ureterolithotomies, three nephrectomies and three pyelolithotomies, all performed by the retroperitoneal laparoscopic approach. The fingerstalls did not burst or come off during inflation, the quality of dissection was satisfactory and all procedures were performed successfully. This simple reusable device provides a reliable and economical method for making a homemade balloon.

Hemolysis in Serum Samples Drawn by Emergency Department Personnel versus Laboratory Phlebotomists

found when the following parameters were compared: distal arm draw versus antecubital fossa draw (P=0.0054), 22 gauge plastic cannula versus 20 gauge cannula (P=0.0104), less than half-full tube draw versus greater than or equal half-full tube draw (P=0.0159), tourniquet compression time of greater than 2 minutes versus less than or equal 2 minutes (P=0.016), and plastic versus metal cannulas ( P=0.0164). Logistic regression of these data to control for confounding variables demonstrated that the following factors contributed most to causing mechanical hemolysis: drawing from a vein in the distal arm and drawing through a narrower gauge needle. Use of a standardized protocol for blood drawing can reduce the rate of pre-analytic hemolysis by more than 7-fold. Drawing blood from the antecu

A Review of Immune Mediated Transfusion Reactions

Observed Technique Study Although the chi-squared analysis showed plastic vs metal cannulas as being significantly different, the logistic regression analysis showed this factor to be noncontributory. Logistic regression analysis revealed that the key variables were site of draw and fullness of the tubes. The antecubital fossa may be more favorable than the distal arm because of the faster flow due to its increased diameter and reduced resistance. In addition, smaller cannulas may be used for distal blood draws. The fullness of the tubes may affect hemolysis through the poorly understood effect of pneumatic tube transportation. Further investigation is necessary to elucidate the causes. The endpoint for hemolysis used in this study, though not quantifiable, is true to life. Samples are rejected not because their spectrophotometer reading indicates excessive hemolysis, but because the technician perceives it to be hemolyzed. Newer clinical chemistry analyzers have built in “hemolysis” flags that reject specimens that exceed a predetermined spectrophotometric standard for hemolysis. The barriers to reducing hemolysis include personal preference and feasibility. It is common in emergency medicine to draw blood samples from the distal arm when placing IVs to reduce the number of venipunctures. Emergency department personnel avoid placing the IV in the antecubital fossa because of the possibility of the catheter bending and obstructing infusions when the patient moves their arm. They are more likely to draw blood from the distal arm. Likewise, it may be difficult to fill a specimen tube despite one’s best efforts. Use of a standardized protocol for blood drawing can reduce the rate of preanalytic hemolysis by more than 7-fold. Hemolysis can best be reduced by drawing blood from the antecubital fossa and by completely filling the tube Acknowledgements

Minimally invasive exploration of the female reproductive tract in infertility

AbstractClassically, invasive and non-invasive tests are performed to evaluate the causes of infertility. Transvaginal hydrolaparoscopy (THL) allows the exploration of the pelvic structures with a mini-endoscope, using a vaginal needle-guided trocar introduction technique and saline as a distension medium. A first study on 349 patients demonstrated the feasibility of the procedure and gave a high patient satisfaction. Access to the pouch of Douglas was achieved in 330 patients (94.5%) under local anaesthesia and in an ambulatory environment. The mean pain score measured on a visual analogue scale of 10 was 2.7, comparable to the score of mini-hysteroscopy only and significantly lower than the scores of hysterosalpingography with either metal cannula or balloon catheter. A total of 96% of the patients agreed to repeat the procedure under the same circumstances if required. The diagnostic accuracy of the technique was demonstrated in a prospective study, in which two independent endoscopists explored 10 patients with both THL and standard laparoscopy. The inter-observer agreement for ovarian adhesions was 75% for standard laparoscopy and 90% for THL. In addition, in patients with mild endometriosis, more peri-ovarian adhesions were detected with THL than with standard laparoscopy. A multinational survey to evaluate the risk and outcome of bowel injury during THL registered 24 (0.65%) cases in 3667 procedures. In all cases, the diagnosis was made immediately and the treatment was conservative without complications.