Retrograde Migration Research Articles

Anastomotic Strictures: Conservative Treatment

Anastomotic Strictures: Conservative Treatment

Relationship between sleep and acid gastro‐oesophageal reflux in neonates

The aim of the present study was to investigate the impact of gastro-oesophageal acid reflux on sleep in neonates and, reciprocally, the influence of wakefulness (W) and sleep stages on the characteristics of the reflux (including the retrograde bolus migration of oesophageal acid contents). The pH and multichannel intraluminal impedance were measured during nocturnal polysomnography in 25 infants hospitalised for suspicion of gastro-oesophageal reflux. Two groups were constituted according to whether or not the infants displayed gastro-oesophageal reflux (i.e. a reflux group and a control group). There were no differences between the reflux and control groups in terms of sleep duration, sleep structure and sleep state change frequency. Vigilance states significantly influenced the gastro-oesophageal reflux pattern: the occurrence of gastro-oesophageal reflux episodes was greater during W (59 ± 32%) and active sleep (AS; 35 ± 30%) than during quiet sleep (QS; 6 ± 11%), whereas the mean duration of gastro-oesophageal reflux episodes was higher in QS than in W and AS. The percentage of retrograde bolus migrations of distal oesophageal acid content was significantly higher in AS (62 ± 26%) than in W (42 ± 26%) and QS (4.5 ± 9%). In neonates, gastro-oesophageal reflux occurred more frequently during W, whereas the physiological changes associated with sleep state increase the physiopathological impact of the gastro-oesophageal reflux. The duration of oesophagus-acid contact was greater during sleep; AS facilitated the retrograde migration of oesophageal acid content, and QS was characterised by the risk of prolonged acid mucosal contact.

A Randomized Prospective Controlled Study for Assessment of Different Ureteral Occlusion Devices in Prevention of Stone Migration During Pneumatic Lithotripsy

To compare the safety and efficacy of two different ureteral occlusion devices (stone cone and entrapment net) in preventing retrograde stone migration during ureteroscopic pneumatic lithotripsy. Proximal migration of stone fragments during ureteroscopic lithotripsy is a common problem, especially when the pneumatic lithotripter is used for stone fragmentation. A total of 195 patients with proximal ureteric stones were prospectively randomized into one of three groups in this study, with 65 patients in each group. In group I, the Stone Cone was used as a ureteral occlusive device; in group II, the N-Trap was used; and in group III (control group), the patients underwent pneumatic lithotripsy without any ureteral occlusive device. The ureteroscopic procedure was completed successfully in 180 patients; 63 patients in group I, 59 patients in group II, and 58 patients in group III. Patients in group I showed significantly lower incidence of stone migration compared with the other 2 groups (P <.05). Both ureteral occlusive devices significantly lowered the incidence of residual fragments (>3 mm), ureteral trauma, operative time, and the need for ureteral stenting compared with control group. The stone-free rate at 3 weeks was 95.24%, 83.05%, and 72.41% in groups I, II, and III, respectively. The patients in group I had a statistically significant stone-free rate compared with the other two groups (P <.05). Auxiliary procedures were required in 3 (4.76%), 10 (16.94%), and 16 cases (27.58%) in groups I, II, and III, respectively. The use of Stone Cone or N-Trap is valuable during ureteroscopic pneumatic lithotripsy for treatment of proximal ureteral stones. Both devices significantly diminish residual fragments, the incidence of ureteral wall trauma, and the need for the auxiliary procedure. However, the stone cone was more effective in preventing proximal stone migration and the subsequent stone-free rate.

Intrarenal Pressures Generated During Deployment of Various Antiretropulsion Devices in an Ex Vivo Porcine Model

Pressurized saline irrigation is commonly used during ureteroscopy, which can cause an increase in intrarenal pressure leading to postoperative pain, sepsis, and renal injury due to pyelovenous and pyelolymphatic backflow. To prevent retrograde stone migration during ureteroscopic lithotripsy, antiretropulsion devices can be deployed, which may or may not protect the kidney against high intrarenal pressures. This study compares the intrarenal pressures generated during the use of two antiretropulsion devices in an ex vivo porcine model. Using an ex vivo porcine model of the urinary system, flexible ureteroscopy was performed at the proximal, mid, and distal ureter. Intrarenal pressures were measured in the absence and presence of a coil-based antiretropulsion device and a multifold film-based device. Intrarenal pressure measurements were obtained while using saline irrigation at a gravity of 84 cm H(2)O and pressures of 150 and 300 mm Hg. The deployment of a coil device resulted in a significant increase in intrarenal pressures during ureteroscopy with pressurized irrigation when compared with intrarenal pressures without a device. The use of a multifold film device that occluded the ureter during ureteroscopy resulted in a decrease in intrarenal pressures at an irrigation pressure of 300 mm Hg when compared with pressures without a device. In the remaining configurations, the intrarenal pressures were only minimally elevated. When comparing the two devices to each other, the multifold film device had significantly lower intrarenal pressures at each configuration. This has potential implications in preventing renal injury and/or sepsis during ureteroscopy. The use of a multifold film antiretropulsion device during ureteroscopy with high-pressure irrigation can potentially protect the kidney from elevated intrarenal pressures.

Intraluminal erosion and retrograde migration of laparoscopic gastric band with high-grade obstruction at gastroesophageal junction

Laparoscopic adjustable gastric banding is generally a well-tolerated procedure, but known complications include excessive band narrowing and obstruction, distal band slippage, perforation, infection, and even gastric volvulus [1]. The radiographic appearance of these various complications on postoperative barium studies has been previously reported [2–5]. We recently encountered 1 patient, however, in whom the gastric band had eroded completely into the lumen of the proximal stomach, causing high-grade obstruction at the gastroesophageal junction.

ULTRASONOGRAPHIC FEATURES OF GRASS AWNS IN THE URINARY BLADDER

Grass awns are a common cause of foreign body disease in animals, but little is known about their presence in the lower urinary tract. The ultrasonographic features of grass awns in vivo and in vitro have been described in detail. The purpose of this report is to describe the clinical and sonographic features of grass awns in the urinary bladder of dogs and cats. Three male Yorkshire terriers (one of which was examined twice) and one female domestic short-haired cat were evaluated for signs of lower urinary tract disease, and an intravesicular grass awn was suspected based on ultrasound examination. The grass awn appeared ultrasonographically as a bladder stone (n = 1) or a linear hyperechoic structure (n = 4) with or without acoustic shadowing that was easy to identify due to contrast with surrounding urine. The presence of a grass awn within the urinary bladder was confirmed during exploratory surgery. In all patients, the route of entry of the grass awn was thought to have been retrograde migration from the urethral opening. The ultrasonographic appearance of grass awns in the bladder is consistent with that in other tissues.

Occurrence of retrograde and reoriented migration during formation of the pontine nucleus

Glenoid retroversion may accelerate glenoid loosening after total shoulder arthroplasty. Accurate measurement of preoperative glenoid deformity is critical for decision-making and prognostication. The purpose of this study was to determine whether glenoid version, inclination, and depth and humeral subluxation measurements on computed tomography (CT) scan slices oriented in the plane of the body differ from those oriented in the scapular plane and those obtained by automated 3-dimensional reconstruction software in the setting of a biconcave B2-type glenoid.Thirty-one preoperative CT scans in patients undergoing total shoulder arthroplasty with Walch B2-type glenoids underwent a standardized measurement protocol by 3 observers. Glenoid version, inclination, and depth and humeral subluxation were measured on 2-dimensional CT images in the plane of the body, on 2-dimensional images in the plane of the scapula, and by a validated, automated 3-dimensional software program.Correction of CT slice axis into the plane of the scapula decreased measured retroversion by 2.4° to 4.7° (P < .004) and inclination by 21° (P < .001). Whereas uncorrected version measurements do not differ from automated software measurements, corrected measurements do (P < .001). Whereas corrected inclination measurements do not differ from automated measurements, uncorrected measurements do (P < .001). Automated measurements differed from both corrected and uncorrected subluxation (P < .001 in both cases).If CT images are not reoriented into the plane of the scapula, version and inclination will be significantly overestimated. In the setting of a retroverted, deformed glenoid, automated software may produce similar inclination measurements to corrected 2-dimensional CT, but it produces significantly altered measurements of version and subluxation.

Bilateral renal artery occlusion due to intraoperative retrograde migration of an abdominal aortic aneurysm endograft

Retrograde (proximal) migration of an abdominal aortic aneurysm endograft is an extremely rare event during endovascular insertion and may lead to occlusion of the bilateral renal arteries and dialysis-dependent renal failure. This case report describes the intraoperative retrograde migration of a bifurcated abdominal aortic endograft during the initial endovascular procedure after deployment of an extender limb graft into the right iliac artery and associated bilateral renal artery occlusion. This was treated with renal artery bypass, and the patient had a favorable outcome.

Dynamic alterations in chemokine gradients induce transendothelial shuttling of human T cells under physiologic shear conditions

The active movement of cells from subendothelial compartments into the bloodstream (intravasation) has been recognized for several decades by histologic and physiologic studies, yet the molecular effectors of this process are relatively uncharacterized. For extravasation, studies based predominantly on static transwell assays support a general model, whereby transendothelial migration (TEM) occurs via chemoattraction toward increasing chemokine concentrations. However, this model of chemotaxis cannot readily reconcile how chemokines influence intravasation, as shear forces of blood flow would likely abrogate luminal chemokine gradient(s). Thus, to analyze how T cells integrate perivascular chemokine signals under physiologic flow, we developed a novel transwell-based flow chamber allowing for real-time modulation of chemokine levels above (luminal/apical compartment) and below (abluminal/subendothelial compartment) HUVEC monolayers. We routinely observed human T cell TEM across HUVEC monolayers with the combination of luminal CXCL12 and abluminal CCL5. With increasing concentrations of CXCL12 in the luminal compartment, transmigrated T cells did not undergo retrograde transendothelial migration (retro-TEM). However, when exposedto abluminal CXCL12, transmigrated T cells underwent striking retro-TEM and re-entered the flow stream [corrected]. This CXCL12 fugetactic (chemorepellant) effect was concentration-dependent, augmented by apical flow, blocked by antibodies to integrins, and reduced by AMD3100 in a dose-dependent manner. Moreover, CXCL12-induced retro-TEM was inhibited by PI3K antagonism and cAMP agonism. These findings broaden our understanding of chemokine biology and support a novel paradigm by which temporospatial modulations in subendothelial chemokine display drive cell migration from interstitial compartments into the bloodstream.

Migration forces of transcatheter aortic valves in patients with noncalcific aortic insufficiency

Transcatheter aortic valves have been successfully implanted into the calcified leaflets of patients with severe aortic stenosis. However, their stability in patients with noncalcified aortic insufficiency is unknown. Similar to thoracic and abdominal aortic stent grafts, transcatheter aortic valves are subjected to antegrade ejection forces during systole. However, retrograde migration forces into the left ventricle are also generated by the diastolic pressure gradient across the closed valve. It has been suggested that leaflet calcification anchors the prosthesis, and measurements of migration forces should be considered before clinical trials in noncalcified aortic insufficiency. The objective of this study was to use computational fluid dynamics simulations to quantify forces that could potentially dislodge the prosthesis. A computational fluid dynamics model was developed to simulate systolic flow through a geometric mesh of the aortic root and transcatheter aortic valves. Hemodynamic measurements were made at discrete moments during ejection. Unsteady control volume analysis was used for calculations of force on the mesh. Results of the simulation indicate that a total force of 0.602 N acts on the transcatheter aortic valves during systole, 99% of which is in the direction of axial flow. The largest contributor to force was the dynamic pressure gradient through the transcatheter aortic valves. This antegrade force is approximately 10 times smaller than the retrograde force (6.01 N) on the closed valve during diastole. Our model simulated systolic flow through a transcatheter aortic valve and demonstrated migration into the left ventricle to be of greater concern than antegrade ejection.

Cytoplasmic Bulk Flow Propels Nuclei in Mature Hyphae of Neurospora crassa

We used confocal microscopy to evaluate nuclear dynamics in mature, growing hyphae of Neurospora crassa whose nuclei expressed histone H1-tagged green fluorescent protein (GFP). In addition to the H1-GFP wild-type (WT) strain, we examined nuclear displacement (passive transport) in four mutants deficient in microtubule-related motor proteins (ro-1, ro-3, kin-1, and a ro-1 kin-1 double mutant). We also treated the WT strain with benomyl and cytochalasin A to disrupt microtubules and actin microfilaments, respectively. We found that the degree of nuclear displacement in the subapical regions of all strains correlated with hyphal elongation rate. The WT strain and that the ro-1 kin-1 double mutant showed the highest correlation between nuclear movement and hyphal elongation. Although most nuclei seemed to move forward passively, presumably carried by the cytoplasmic bulk flow, a small proportion of the movement detected was either retrograde or accelerated anterograde. The absence of a specific microtubule motor in the mutants ro-1, ro-3, or kin-1 did not prevent the anterograde and retrograde migration of nuclei; however, in the ro-1 kin-1 double mutant retrograde migration was absent. In the WT strain, almost all nuclei were elongated, whereas in all other strains a majority of nuclei were nearly spherical. With only one exception, a sizable exclusion zone was maintained between the apex and the leading nucleus. The ro-1 mutant showed the largest nucleus exclusion zone; only the treatment with cytochalasin A abolished the exclusion zone. In conclusion, the movement and distribution of nuclei in mature hyphae appear to be determined by a combination of forces, with cytoplasmic bulk flow being a major determinant. Motor proteins probably play an active role in powering the retrograde or accelerated anterograde migrations of nuclei and may also contribute to passive anterograde displacement by binding nuclei to microtubules.

Carbon dioxide embolism induced right coronary artery ischaemia during off-pump obtuse marginalis artery grafting

Although use of carbon dioxide (CO2) blower has been regarded safe during off-pump coronary bypass surgery (OPCAB), we experienced a case of right coronary artery ischaemia induced by retrograde CO2 embolism originating from the opened obtuse marginalis artery during OPCAB. The spray pressure can exceed the diastolic pressure, especially during grafting at the lateral or posterior wall when haemodynamic compromise due to mechanical heart displacement is most severe. In this situation, CO2 blowing at an incompletely slinged coronary arteriotomy site can result in retrograde migration of CO2 into the ascending aorta causing coronary embolism of the right coronary artery. When signs of ischaemia on the right coronary artery are encountered during grafting of other coronary artery, although CO2 blower has been used, gas embolism should also be considered as the cause and identified at the mid-oesophageal aortic valve long-axis view. When confirmed, the use of gas blower should immediately be discontinued and coronary perfusion pressure increased while allowing time for the CO2 to be absorbed. In case of massive embolism, needle aspiration of the gas should also be considered.

THE USE OF A NOVEL THERMOSENSITIVE POLYMER (BACKSTOP™) TO PREVENT PROXIMAL URETERIC STONE RETROPULSION DURING INTRACORPOREAL LITHOTRIPSY: A PROSPECTIVE RANDOMIZED CONTROLLED CLINICAL STUDY

INTRODUCTION AND OBJECTIVES: We present a randomized controlled prospective study using BackStopTM (Pluromed Inc, Woburn, MA), a novel reverse thermosensitive, water soluble polymer that is injected above the stone as a low viscosity gel, and which rapidly transitions to a high viscosity gel at body temperature, thereby occluding the ureter and preventing retrograde stone migration during intracorporeal lithotripsy. After fragmentation is completed and concretions extracted, conventional irrigation with saline dissolves the polymer, which is then flushed out. METHODS: A total of sixty-eight eligible subjects have been consented and randomly assigned to either the experimental group (BackStopTM) or the control group (no anti-retropulsion device). All subjects were indicated for ureteroscopic lithotripsy to treat single, radiopaque stones located in the proximal ureter. Primary endpoints include a determination of the effectiveness of BackStopTM in preventing retrograde stone migration during intracorporeal lithotripsy and an assessment of its “removal” via dissolution. The volume used, stone free rates and necessity of secondary procedures, if any, were also documented. RESULTS: The rate of stone retropulsion in the BackStop group was 8.8% (3/34) compared to 52.9% (18/34) in the control group (p=.0002). CONCLUSIONS: BackStop safely and significantly reduces the incidence of retropulsion of ureteral stones during intracorporeal lithotripsy.

Stone Cone® in ureteroscopic ballistic lithotripsy of proximal ureteral stones

Stone Cone® (Microvasive-Boston Scientific Corp, USA) is a device which prevents retrograde calculus migration during endoscopic ureterolithotripsy. We have studied the safety and efficacy of this device in endoscopic ureterolithotripsy with ballistic energy in proximal ureteral stones. Materials and Methods. From 01/02/2006 to 01/02/2008 we carried out 36 ureterorenoscopies (URS) for proximal ureteral stones (average age: 46, range: 15–73). A ballistic energy was used for stones fragmentation. In 18 patients (Group A) we carried out URS with the aid of Stone Cone®, which was not used in the other 18 patients (Group B). Semirigid 8 Ch or 10 Ch Storz ureteroscope and ballistic lithotriptor Swiss Lithoclast Master EMS® were used. In cases of migration, edema, and ureteral damage, a ureteral stent was used. Results. In Group B patients (URS performed without Stone Cone®) the migration of the whole stone, or of clinically significant fragments, occurred 8 times (45%). All of these patients underwent external shockwave lithotripsy (ESWL) at a center equipped with a lithotriptor. A ureteral stent was placed in 14 cases (78%). In Group A, the migration of a stone requiring ESWL treatment occurred only once (5%). The ureteral stent was placed 8 times (45%). We had no significant complications during the procedure. Conclusions. The Stone Cone® is a safe and easy-to-use device. The cost of this device can be balanced by the reduction of postoperative ESWL treatments for lithiasic fragments pushing up into the kidneys (p&lt;0.01), and of ureteral stent applications at the end of the procedure (p&lt;0.05).

Sudden unilateral visual loss after autologous fat injection into the nasolabial fold

A 27-year-old female presented with sudden visual loss of her right eye after receiving an autologous fat injection into the right nasolabial fold. Fundus examination of the right eye showed multiple whitish patchy lesions with macular edema. Fluorescein angiogram showed deterioration of choroidal circulation with patchy choroidal filling and arm-to-retina circulation time and retinal arteriovenous passage time were delayed to 30 seconds and 20 seconds, respectively. There was no response in flash visual evoked potential (VEP). High dose steroid therapy (methylprednisolone 1 g/day/i.v.) was done and about 2 weeks later, the disc edema subsided and retinal arteriovenous passage time of fluorescein angiogram was normalized but there was no improvement in visual acuity. Absence of a cherry red spot, deterioration of choroidal circulation with patchy choroidal fillings seen in fluorescein angiogram, and no response in flash VEP suggests multiple choroidal infarction due to perfusion defect of the short posterior ciliary artery. The autologous fat injected is thought to have entered the dorsal nasal artery and the retrograde migration of the emboli to the ophthalmic artery might have caused the multiple occlusions of the short posterior ciliary artery.

A Randomized Clinical Trial of Lidocaine Jelly for Prevention of Inadvertent Retrograde Stone Migration During Pneumatic Lithotripsy of Ureteral Stone

We studied the efficacy of lidocaine jelly instillation proximal to the ureteral stone during intracorporeal lithotripsy using a semirigid ureteroscope for the prevention of retrograde migration and improvement in stone-free rate. From November 2006 to September 2007, 50 patients with 5 to 18 mm ureteral stones undergoing ureteroscopic removal using pneumatic lithotripsy were randomized into 2 groups. Group 1 (25 patients) had lidocaine jelly instilled proximal to the stone before and after fragmentation, and group 2 was the control group (25 patients). Ureteroscopy was performed using an 8 or 6.4Fr semirigid ureteroscope. A 5Fr ureteral stent was advanced beyond the stone. Lidocaine jelly (2 ml) was instilled and lithotripsy was performed with a Swiss LithoClast . A 5Fr ureteral catheter was left in place for 24 hours. Patients were followed at 24 hours with plain x-ray of the kidneys, ureters and bladder, and at 2 weeks with noncontrast enhanced computerized tomography of the kidneys, ureters and bladder. The 2 groups were comparable with regard to age and stone size. Stone or stone fragment migration occurred in 4% and 28% of patients in groups 1 and 2, respectively, and this difference was statistically significant (p = 0.002). At 2 weeks followup with imaging the stone-free rate was 96% and 72% in groups 1 and 2, respectively, and this difference was also statistically significant (p = 0.045). Although the mean operative time was slightly longer in the treatment group (33.56 +/- 13 vs 35.84 +/- 12.5 minutes) the difference was not significant (p = 0.450). Lidocaine jelly instillation proximal to ureteral calculi during lithotripsy is an effective method of preventing retrograde stone displacement as well as significantly improving the stone-free rate.

Use of the Escape™ Nitinol Stone Retrieval Basket Facilitates Fragmentation and Extraction of Ureteral and Renal Calculi: A Pilot Study

Advances in ureteroscope and stone basket design have catapulted ureteroscopy to the forefront of surgical stone management; however, persistent problems such as stone migration continue to challenge urologists. The Escape nitinol stone retrieval basket (Boston Scientific, Natick, MA) is a stone basket designed to capture calculi and facilitate simultaneous laser lithotripsy in situ. We report our initial experience with the Escape basket for the management of urinary calculi and compare the use of this device with other methods of optimizing ureteroscopic stone management. A prospective evaluation of 23 patients undergoing ureteroscopic holmium:yttrium-aluminum-garnet laser lithotripsy of urinary calculi was performed at two institutions by two surgeons (R.M. and G.M.P). The Escape basket was used to prevent retrograde ureteral stone migration or to facilitate fragmentation and extraction of large renal calculi. Patient demographics and perioperative parameters were assessed. Twenty-three patients (16 men, 7 women), with a mean age of 55.5 years (range 33-74 yrs) were treated for renal (n = 9) or ureteral (n = 14) calculi. The mean stone diameter was 1.4 cm (range 0.4-2.5 cm), mean fragmentation time was 44.1 minutes (range 10-75 min), and mean energy used was 3.1 kJ (range 0.4-10.6 kJ). No complications were encountered. Eighty-seven percent (20/23) of patients were rendered completely stone free after ureteroscopic laser lithotripsy using the Escape basket. Of the three patients with residual calculi, one patient with a 2.5-cm renal calculus had residual fragments larger than 3 mm, and two patients with large renal calculi had residual fragments smaller than 3 mm. The Escape basket appears to be safe and effective in preventing stone migration and facilitating ureteroscopic laser lithotripsy and stone extraction.

A Retrospective Review of the Types of Chronic Sialadenitis Encountered and Outcomes of Sialoendoscopic Treatment at New York University/Bellevue Hospital

There are many potential factors that can initiate and propagate recurrent sialadenitis. The primary initiating factor of sialadenitis is either a decrease, or a complete cessation, of salivary flow. Salivary stagnation allows a retrograde bacterial migration of the oral flora into the sterile gland, initiating an immune and inflammatory response, termed bacterial sialadenitis. The inflammation causes damage to the epithelium and fibrotic tissue formation causing adhesions and strictures. Partial obstruction of the gland is gradually followed by salivary retention and duct dilatation, leading to recurrent infections and propagation of adhesion formation.

Patient preparation for safe removal of surgical drains

Drains are a common feature of the post-operative management of surgical patients. While drains serve an important function they are also associated with complications such as haemorrhage, tissue inflammation, retrograde bacterial migration and drain entrapment. It is therefore essential that nurses are familiar with the monitoring and management of surgical drains, but also the process involved in their removal.

Implantation transapicale d'une valve stentée aortique : résultats expérimentaux

Objective Percutaneous aortic valve replacement has been performed in humans mainly for non-surgical candidates. We evaluated on animals a transapical approach to deliver an aortic stented valve without cardiopulmonary bypass. Methods A tubular pericardial valve fixed within a cobalt-nickel stent (Medtronic, Inc.) was implanted using a transapical approach in five adult sheep. A left thoracotomy was used to access the apex of the heart. The crimped valve was deployed in orthotopic position with a valvuloplasty balloon catheter on the beating heart after decreasing the left ventricular pressure by using either drugs or inferior vena cava occlusion. Deployments were performed under fluoroscopy and epicardial 2D Doppler echocardiography. Exact positioning of the valve into the target area was confirmed by autopsy at the end of the procedures. Results Valves were unsuccessfully deployed at the target site in all cases but one. Three valves were implanted in a supra-annular position with two of them in supracoronary position. One valve was implanted below the native annulus in the outflow tract. Valvular leak was noted in all but one implants. Coronary obstruction occurred twice and early valve retrograde migration once. Ventricular fibrillation or diastolic cardiac arrest occurred less than 20 minutes after stent deployment in all cases. Conclusion In our experience the transapical approach does not facilitate delivery of a stented valve. Despite its technically feasibility, advanced stent design and improvements in delivery system are required before to continue experimental studies in transapical approach for aortic stented valve.