Subsequent Cannulation Research Articles

Successful hemostasis and subsequent cannulation using a self-assembling peptide hydrogel for bleeding after precut sphincterotomy.

Successful hemostasis and subsequent cannulation using a self-assembling peptide hydrogel for bleeding after precut sphincterotomy.

Trans-urethral snare stent removal: a novel, self-constructed innovation for simultaneous ureteral stent removal and safety guidewire insertion.

Ureteral stent insertion and subsequent removal remains one of the most common procedures performed in endourology. We aimed to evaluate a novel, one-step method, permitting simultaneous stent removal and guidewire passage using a self-constructed suture snare via standard cystoscopy. This method should be used prior to ureteroscopy, in cases of minimal stent encrustation and peri-ureteral mucosal oedema, where identification and subsequent cannulation of the ureteral orifice may be a challenge. A self-constructed suture snare is constructed using an open-ended ureteral catheter to facilitate this novel 'Switch' technique. Operative duration, cost feasibility and potential complications with this novel method were assessed in patients with an indwelling stent duration above 100 days. Age inclusion in this study ranged from 21 to 35 years, with kidney, ureter and bladder scores below 6, in the five patients assessed. Previous ureteral stent indwelling time ranged from 106 to 315 days. Reasons for (pre-stented) ureteroscopy were mostly stone related. The overall recorded procedure time for the Switch technique was successfully performed in less than 96 s (range 68-95 s) in all cases within this series. No procedure-related complications were reported. Utilizing the suture snare, the novel Switch technique was successfully performed in all cases assessed. This method is both time and cost feasible and could be easily utilized in resource-limited areas, regional centres or in cases where a stent grasper is not available, may have malfunctioned or cannot adequately approximate due to distal ureteral stent encrustation.

Right inferior phrenic artery; Don't miss on MDCT before chemoembolization of hepatic dome HCC

BackgroundTransarterial chemoembolization (TACE) is considered a standard local-regional treatment for intermediate-stage hepatocellular carcinoma (HCC) and the most common bridging therapy. HCC typically receives its blood supply from the hepatic artery; however, it can recruit a parasitic supply from extrahepatic collateral arteries. The right inferior phrenic artery (RIPA) is considered the most common extrahepatic collateral pathway supplying HCC and so interfere with the therapeutic efficacy of TACE resulting in treatment failure and poor outcome. Imaging by MDCT with angiography has an essential role in depicting the presence or absence of an EHC arterial supply during the pre-TACE evaluation. We analyzed MDCT studies with CT angiography of patients with hepatic dome HCC retrospectively to confirm the diagnosis of HCC and to assess its blood supply. All patients were subjected to a proper assessment by history, clinical examination, as well as routine laboratory investigationsResultsOur study includes 58 cases with hepatic dome HCC. On CT angiography, the extrahepatic collateral from the RIPA supplying hepatic dome HCC was detected in about 33 out of 58 cases (56.9%). The RIPA arose directly from the aorta in 30 cases (90.9%) with only three cases (9.1%) from the celiac trunk. All cases were managed with TACE with about 25 out of 33 cases (75.8%) with extrahepatic RIPA were undergone concomitant embolisation of both RIPA and hepatic artery during TACE procedure.ConclusionMDCT assesses well the HCC arterial supply which is fundamental for planning subsequent cannulation and embolization of extrahepatic RIPA supply to hepatic dome HCC.

Maintaining the permanence principle for death during in situ normothermic regional perfusion for donation after circulatory death organ recovery: A United Kingdom and Canadian proposal.

There is international variability in the determination of death. Death in donation after circulatory death (DCD) can be defined by the permanent cessation of brain circulation. Post‐mortem interventions that restore brain perfusion should be prohibited as they invalidate the diagnosis of death. Retrieval teams should develop protocols that ensure the continued absence of brain perfusion during DCD organ recovery. In situ normothermic regional perfusion (NRP) or restarting the heart in the donor's body may interrupt the permanent cessation of brain perfusion because, theoretically, collateral circulations may restore it. We propose refinements to current protocols to monitor and exclude brain reperfusion during in situ NRP. In abdominal NRP, complete occlusion of the descending aorta prevents brain perfusion in most cases. Inserting a cannula in the ascending aorta identifies inadequate occlusion of the descending aorta or any collateral flow and diverts flow away from the brain. In thoracoabdominal NRP opening the aortic arch vessels to atmosphere allows collateral flow to be diverted away from the brain, maintaining the permanence standard for death and respecting the dead donor rule. We propose that these hypotheses are correct when using techniques that simultaneously occlude the descending aorta and open the aortic arch vessels to atmosphere.

Laparoscopic-assisted ERCP

Background: Conventional ERCP has become the gold standard for visualization and extraction of common bile duct stones. Gastric bypass patients pose a unique challenge, especially in a community setting in which double-balloon ERCP is not readily available. Several modalities are available for this patient population, including: PTC, double balloon ERCP, and open/laparoscopic surgery. Our patient―a 71 year old female with history of cholecystectomy and multiple bariatric surgeries, including gastric bypass―was admitted and treated for cholangitis. IV antibiotics per sepsis protocol were initiated and definitive treatment was done by laparoscopic-assisted ERCP. Methods: The procedure was done under general endotracheal anesthesia. Five trocar technique was performed using 12 mm supraumbilical Hasson trocar for camera, 5 mm RUQ, RLQ and LLQ trocars for instruments, and 15 mm RUQ trocar for endoscope. Extensive lysis of adhesions were taken down with combined blunt and sharp dissection using harmonic scalpel and endoshears. The gastric remnant was identified and entered between two stay sutures using harmonic scalpel. Esophagogastroduodenoscope was inserted through 15mm RUQ port and gastrotomy. ERCP was then successfully performed by the gastroenterologist with extraction of two large stones and subsequent visualization of clear biliary tract on fluoroscopy. Gastrostomy was subsequently closed by endo-GIA 65 mm blue load and over-sewn with 3-0 silk sutures. Results: Operative time was approximately 180 minutes including intraoperative ERCP. Blood loss was estimated at 10cc. Successful entry into the gastric remnant and subsequent cannulation of Ampulla of Vater with extraction of 2 large common bile duct stones was achieved71-year-old and subsequent visualization of clear biliary tract on fluoroscopy was seen. The patient tolerated surgery well with normalization of abnormal labs by postoperative day 2 with subsequent discharge home in stable and improved condition. Conclusion: Laparoscopic-assisted ERCP may be a viable treatment modality for patients with history of multiple bariatric surgeries presenting with cholangitis, especially in a community setting where double-balloon ERCP is limited.

The Vanishing Target Sign: Confirmation of Intraluminal Needle Position for Ultrasound Guided Vascular Access

Ultrasound-guided peripheral intravenous (USG-PIV) catheter placement has been described in the emergency medicine literature for more than a decade.1 Several studies have shown that USG-PIV placement can decrease the number of needle insertion attempts, decrease the number of potentially unnecessary central line placements, and increase patient satisfaction scores.1-5 Additional evidence has shown that this skill is accessible to ED staff other than physicians.6, 7 However, a randomized study of USG-PIV placement by emergency physicians with variable levels of experience did not demonstrate improved success rates, decreased time to insertion, or increased patient satisfaction.8 In our experience, consistent success with USG-PIV placement in patients with difficult access using a dynamic one-person technique is a challenging procedure. In an attempt to help teach this effectively, we have developed a method that employs a sign we call the “vanishing target” to ensure intraluminal positioning of the catheter needle tip. When ultrasound is used to guide needle placement into a vessel, two traditional approaches are employed: a short-axis, or out-of-plane, approach, and long-axis, or in-plane, approach. The long axis in-plane technique has the advantage of visualizing the needle shaft and tip, but the short-axis, out-of-plane technique has been shown to be more readily used by less experienced operators.9 A recent video on the subject stated that the long-axis, in-plane technique is more frequently used for USG-PIV by experienced operators10; however, in our experience, a long axis, in-plane approach is less useful for peripheral veins (regardless of operator experience level), as these veins tend to be small, are accompanied by arteries, and often do not travel in straight lines. With the out-of-plane, short axis approach, the needle tip is visualized within the vessel lumen as a hyperechoic structure, also known as the target sign (Figure 1). Obtaining a target sign does not guarantee that the needle tip is indeed intravascular and represents a potential pitfall of using this approach. At times, the vessel wall “tents” and deforms to the pressure of the needle tip but the tip remains extravascular (Video Clip S1, available as supporting information in the online version of this paper). Also, the “bull's eye” of the target sign may not always represent the true needle tip, as the ultrasound plane may be cutting across the needle more proximal to its tip. This can result in the needle tip penetrating deeper than anticipated, resulting in inadvertent puncture of the vein's posterior wall, also known as “back-walling” the needle. We propose an additional method to confirm intravascular positioning of the needle tip using an ultrasound guided out-of-plane, short-axis approach. Once a target sign is obtained, the operator should decrease the angle between the needle and skin and then advance both the needle and the catheter 1 mm to 2 mm farther while keeping the target sign centered and visualized within the vessel. As the probe is fanned distally, the bull's eye of the target sign should stay in the center of the vessel for a couple of ultrasound planes, but disappear as fanning continues distally from the point of needle entry. This confirms that the needle tip is truly intravascular and will allow for subsequent cannulation of the vessel. Video Clip S2 (available as supporting information in the online version of this paper) demonstrates the “vanishing target sign” technique of USG-PIV placement. While helpful for peripheral vascular access, this technique can also be used for any ultrasound-guided procedure necessitating precise knowledge of the location of a needle tip. It may help avoid misplacement of the needle during central vascular access as well, where location of the needle tip in the short axis is particularly important. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Challenging the Distal-to-Proximal Cannulation Technique for Administration of Anticancer Therapies

Distal-to-proximal technique has been recommended for anticancer therapy administration. There is no evidence to suggest that a 24-hour delay of treatment is necessary for patients with a previous venous puncture proximal to the administration site. This study aims to identify if the practice of 24-hour delay between a venous puncture and subsequent cannulation for anticancer therapies at a distal site is necessary for preventing extravasation. A prospective cohort study was conducted with 72 outpatients receiving anticancer therapy via an administration site distal to at least 1 previous venous puncture on the same arm in a tertiary cancer center in Australia. Participants were interviewed and assessed at baseline data before treatment and on day 7 for incidence of extravasation/phlebitis. Of 72 participants with 99 occasions of treatment, there was 1 incident of infiltration (possible extravasation) at the venous puncture site proximal to the administration site and 2 incidents of phlebitis at the administration site. A 24-hour delay is unnecessary if an alternative vein can be accessed for anticancer therapy after a proximal venous puncture. Infiltration can occur at a venous puncture site proximal to an administration site in the same vein. However, the nurse can administer anticancer therapy at a distal site if the nurse can confidently determine that the vein of choice is not in any way connected to the previous puncture site through visual inspection and palpation.

Cardiac Resynchronization Therapy: Double Cannulation Approach to Coronary Venous Lead Placement via a Prominent Thebesian Valve

We report identification of a prominent Thebesian valve by cardiovascular computed tomography (CT) angiography impeding cannulation of the coronary sinus, with subsequent successful coronary venous lead placement with cannulation of the coronary sinus ostium via a transvenous femoral vein approach and subsequent cannulation of the ostium with the coronary venous lead with a left subclavian approach. A 57-year-old man with nonischemic dilated cardiomyopathy, New York Heart Association Class III heart failure, left bundle branch block, and an ejection fraction of 15%, underwent an attempted cardiac resynchronization therapy implantable cardiac defibrillator (ICD). As the coronary sinus ostium could not be cannulated, a dual chamber ICD was placed. The patient subsequently underwent cardiovascular CT angiography, which identified a prominent Thebesian valve at the coronary sinus ostium as the anatomic obstacle to cannulation. Reattempted transvenous cardiac resynchronization therapy was accomplished successfully with a double cannulation approach: cannulation of the coronary sinus ostium with a catheter via a transvenous femoral vein approach and subsequent cannulation with the coronary venous lead via a left subclavian approach. When a prominent Thebesian valve is identified as an obstacle to transvenous left ventricular lead placement, cannulation of the coronary sinus by an alternate venous approach may allow for a coronary venous route rather than necessitate an epicardial approach.

Reflexes from pulmonary arterial baroreceptors in dogs: interaction with carotid sinus baroreceptors

In contrast to the reflex vasodilatation occurring in response to stimulation of baroreceptors in the aortic arch, carotid sinuses and coronary arteries, stimulation of receptors in the wall of pulmonary arteries results in reflex systemic vasoconstriction. It is rare for interventions to activate only one reflexogenic region, therefore we investigated how these two types of reflexes interact. In anaesthetized dogs connected to cardiopulmonary bypass, reflexogenic areas of the carotid sinuses, aortic arch and coronary arteries and the pulmonary artery were subjected to independently controlled pressures. Systemic perfusion pressure (SPP) measured in the descending aorta (constant flow) provided an index of systemic vascular resistance. In other experiments, sympathetic efferent neural activity was recorded in fibres dissected from the renal nerve (RSNA). Physiological increases in pulmonary arterial pressure (PAP) induced significant increases in SPP (+39.1 ± 10.4 mmHg) and RSNA (+17.6 ± 2.2 impulses s(−1)) whereas increases in carotid sinus pressure (CSP) induced significant decreases in SPP (−42.6 ± 10.8 mmHg) and RSNA (−42.8 ± 18.2 impulses s(−1)) (P < 0.05 for each comparison; paired t test). To examine possible interactions, PAP was changed at different levels of CSP in both studies. With CSP controlled at 124 ± 2 mmHg, the threshold, 'set point' and saturation pressures of the PAP–SPP relationship were higher than those with CSP at 60 ± 1 mmHg; this rightward shift was associated with a significant decrease in the reflex gain. Similarly, increasing CSP produced a rightward shift of the PAP–RSNA relationship, although the effect on reflex gain was inconsistent. Furthermore, the responses to changes in CSP were influenced by setting PAP at different levels; increasing the level of PAP from 5 ± 1 to 33 ± 3 mmHg significantly increased the set point and threshold pressures of the CSP–SPP relationship; the reflex gain was not affected. These results indicate the existence of interaction between pulmonary arterial and carotid sinus baroreceptor reflexes; physiological and pathological states that alter the stimulus to one may alter the reflex responses from the other.

MDCT Anatomic Assessment of Right Inferior Phrenic Artery Origin Related to Potential Supply to Hepatocellular Carcinoma and its Embolization

To prospectively assess the anatomic variation of the right inferior phrenic artery (RIPA) origin with multidetector computed tomography (MDCT) scans in relation to the technical and angiographic findings during transcatheter arterial embolization of hepatocellular carcinoma (HCC). Two hundred patients with hepatocellular carcinomas were examined with 16-section CT during the arterial phase. The anatomy of the inferior phrenic arteries was recorded, with particular reference to their origin. All patients with subcapsular HCC located at segments VII and VIII underwent arteriography of the RIPA with subsequent embolization if neoplastic supply was detected. The RIPA origin was detected in all cases (sensitivity 100%), while the left inferior phrenic artery origin was detected in 187 cases (sensitivity 93.5%). RIPAs originated from the aorta (49%), celiac trunk (41%), right renal artery (5.5%), left gastric artery (4%), and proper hepatic artery (0.5%), with 13 types of combinations with the left IPA. Twenty-nine patients showed subcapsular HCCs in segments VII and VIII and all but one underwent RIPA selective angiography, followed by embolization in 7 cases. MDCT assesses well the anatomy of RIPAs, which is fundamental for planning subsequent cannulation and embolization of extrahepatic RIPA supply to HCC.

Emergency cricothyrotomy

Emergency cricothyrotomy

Comparison of invasive and non-invasive tonometry in the mouse

Assessment of the accuracy of non-invasive rebound tonometry, and comparison with invasive cannulation tonometry. An in vivo calibration technique was devised to improve the accuracy of the rebound tonometer. IOP was then measured in SW mice using both rebound and cannulation tonometry. The ability of the rebound tonometer to accurately measure small IOP reductions after instillation of a topical prostaglandin was also determined. With the rebound method, mid-afternoon IOP in two groups of similar aged SW mice was 15.9±3.9 mmHg (mean± s.d., n=25) compared to 16.3±1.2 mmHg ( n=32) using the cannulation technique. This difference was not statistically significant ( p=0.6). For serial measurements using both techniques in the same eyes of a third group of SW mice ( n=14), mean IOP was 15.0±3.9 mmHg for rebound tonometry but only 13.4±2.3 mmHg for subsequent cannulation tonometry. This effect was subsequently shown to be a consequence of the rebound tonometry, as multiple rebound measurements induced a statistically significant reduction in IOP. The average IOP reduction observed 2 hr after a single application of topical latanoprost (200 ng) was 2.8±1.3 mmHg ( p<0.001) and 2.4±4.7 mmHg ( p=0.03) with cannulation and rebound tonometers, respectively. These differences were not significantly different ( p=0.8). In vivo calibration of the rebound tonometer increased measurement accuracy and provided IOP values within the physiological range that agreed closely with the IOP measured by cannulation tonometry. However, IOP measurement with the rebound tonometer had larger variability compared with the cannulation method. Repeat IOP measurements with the rebound tonometer led to a reduction in IOP. The rebound tonometer was sufficiently sensitive to detect a 2–3 mmHg reduction in IOP following application of topical latanoprost. Despite these limitations, the rebound tonometer has a significant advantage over cannulation tonometry in that it permits longitudinal IOP measurement in conscious mice.

Implantation of a left ventricular assist device, back-to-front, in an adolescent with a failing mustard procedure

easier. The aorta was crossclamped and blood cardioplegic solution was administered antegradely. The optimal positioning of the HeartMate vented electric device was back-tofront, with the inflow directed toward the diaphragmatic wall of the right ventricle and the outflow toward the apex region. Two incisions were made in the diaphragm corresponding to the inflow and outflow tracts. To avoid damage to the liver, from the front of the pump, we made a “pillow” from polytetrafluoroethylene (Preclude pericardial membrane*) stuffed with Dacron felt. When the device was in place, the inflow was on the right side and the outflow on the left side (Fig 2). An expected pulmonary hypertension was prevented with inhaled aerosolized epoprostenol (prostacyclin).4 The early postoperative course in the intensive care unit was uneventful, and after 2 weeks the patient was transferred to the ward. Five weeks after the operation the patient was discharged from the hospital to his home, located 1500 km from our hospital, to await a donor heart. Comment. The need for assist devices in patients with complex congenital heart conditions, as after atrial correction for transposition of the great arteries, could be a surgical technical challenge. Because the right ventricle is the systemic ventricle in transposition, several points must be considered. To place the device on the right side in the abdomen Implantation of mechanical assist devices has saved the lives of patients awaiting heart transplantation.1 The HeartMate left ventricular assist device (Thermo Cardiosystems, Inc, Woburn, Mass) is made to connect the inflow cannula to the apex of the left ventricle.2 We describe a successful case in which the device was placed back-to-front with the inflow cannula inserted into the diaphragmatic wall of the right ventricle and the outflow graft through the left side of the diaphragm and in the left pleura to the ascending aorta (Fig 1). Medical history. A 15-year-old boy who was born with transposition of the great arteries underwent several balloon septostomies at birth because of desaturation. Despite this treatment, the desaturation was persistent. He therefore underwent an operation on an emergency basis at 3 months of age with an atrial switch as described by Mustard (pericardial baffle). At 4 years of age he required a reoperation because of residual atrial shunt and stenosis of the superior vena cava. Ten days after this operation a VVI pacemaker system was implanted because of atrioventricular dissociation. He then had an active life for almost 9 years, after which he gradually noted progressive fatigue and dyspnea. He had a cough, nausea, and cyanosis. Cardiac assessment revealed severe biventricular failure, gross atrioventricular valve regurgitation, and pulmonary hypertension (although reversible), and he was listed for heart transplantation. Despite “optimal” inotropic support, his condition continued to deteriorate with signs of multiorgan failure. Because no donor was available, we decided to implant a HeartMate left ventricular assist system, even though we expected major technical difficulties since the right ventricle, where the inflow cannula had to be placed, was the systemic ventricle. Surgical procedure. A median sternotomy was performed, and the heart, which was heavily adherent, was carefully dissected. Because the patient was thin, we decided to place the pump intraperitoneally.3 The aorta was cannulated. The systemic atrium was cannulated, and a left-sided bypass was instituted. This made the subsequent cannulation of the cavae

Subclavian vein anatomic subtypes defined by digital cinefluroscopic venography prior to permanent pacemaker lead insertion.

Digital cinefluoroscopic venography of the subclavian vein was performed in 26 consecutive patients. The optimal stored image of the anticipated venipuncture site was magnified, road mapped, and used to compare with fluoroscopic-guided venipuncture. Two anatomic subtypes for both subclavian veins were observed. For the left subclavian vein, a gradual curve was seen most often (57%), while the remainder (43%) exhibited an "s"-shaped curve. For the right subclavian, a gradual curve was observed most frequently (60%) while an acute 90 degrees angle was noted in the remainder (40%). The "s"-shaped curve in the left subclavian vein necessitated redirection of the needle site both laterally and cranially. In three or 12% of patients venography showed either subclavian thrombosis or a persistent left superior vena cava and lead insertion was moved to the opposite side. Successful venipuncture and subsequent cannulation of the subclavian vein was achieved with the first or second passage of the needle in 22 or 85% of the 26 patients. Digital cinefluoroscopic venography appears to be both safe and rapid and may facilitate insertion of permanent pacemaker leads into the subclavian vein.

Abrogation of Afferent Lymph Dendritic Cell Function after Cutaneously Applied Chemical Carcinogens

Chemical carcinogens reduce cutaneous immunity, an event accompanied by alterations to the number and morphology of the resident epidermal Langerhans cell (LC) population. This study aimed to examine the functional capacity of LC and other dendritic cells (DC) that are migrating from carcinogen-treated skin via afferent lymphatic vessels. Generation and subsequent cannulation of prefemoral pseudoafferent lymphatic vessels in sheep allowed continuous collection of DC migrating from a defined area of carcinogen-treated skin. The ability of metrizamide-enriched afferent lymph DC to present antigen to autologous primed peripheral blood lymphocytes was used as an indicator of DC function. Topical application of the complete carcinogens 7,12-dimethylbenz[a]anthracene and benzo[a]pyrene abrogated the stimulatory capacity of migrating DC for periods of 8 weeks and 5 weeks, respectively, whereas the tumor promoter 12-O-tetradecanoylphorbol-13-acetate reduced DC function for less than 1 week. These findings favor tumor development in carcinogen-treated skin being enhanced due to impairment of DC immunological surveillance.

Percutaneous Transcholecystic Approach to the Rendezvous Procedure when Transhepatic Access Fails

Extrahepatic biliary obstruction can be managed endoscopically or percutaneously. When endoscopic therapy fails, percutaneous drainage with or without endoscopic assistance may be performed. However, transhepatic drainage may itself be unsuccessful. In such patients, a transcholecystic approach combined with endoscopic therapy was used to achieve biliary drainage. After attempts at transhepatic biliary drainage failed, a percutaneous cholecystostomy was performed in four patients, with subsequent cannulation of the common bile duct, endoprosthesis insertion, or papillotomy. The success rate was 100%, with no major complication or procedure-related mortality. Slight bleeding from a sphincterotomy was the only minor complication. When percutaneous transhepatic access to the bile duct fails, the transcholecystic route can be safely used with care to successfully achieve biliary drainage.