Sudden Pressure Increase Research Articles

Computational Fluid Dynamics Investigations of Shock Waves in Safety Relief Valves

Safety Relief Valves plays an important role in any pressurised system. The proper design of safety relief valves should consider the eective opening and closing characteristics to achieve the desired valve performance. One of the challenges in any valve design is the elimination of Shock waves. Shock waves are characterised by sudden pressure increase and Mach number drop. Detecting shock waves in safety relief valves using computational uid dy- namics could asses valve design to eliminate the shock waves. I t have been proven that the Reynolds Averaged Navier Stocks (RANS) equations with the k- turbulence model could model the internal gas ow in safety relief valves. The RANS and k- turbulence have been solved by a commercial CFD code. In safety valves discharge ow rate and closing and opening behaviours dependon the upstream pressure and certain critical areas. In this study, the eect of the upstream pressure has been discussed. Upstream pressure range was from 7 to 140 bars. The eect of the valve geometry has been discussed as well. Dierent critical outlet areas and divergent angles have been changed to investigate its eect on the shock wave parameters.The upstream pressure eect on shock wave occurrence and intensity have been studied. The results showed that, computational uid dynamics can be used to predict the location of the shock wave. In addition to determining the pressure peak and the Mach number drop and other properties which help eliminating shock wave occurrence in valve design. An e cient design should consider the geometrical and ow parameters that aect the shock wave occurrence and intensity.

Autonomic Dysreflexia and Posterior Reversible Encephalopathy Syndrome

Autonomic dysreflexia is a syndrome of massive imbalanced reflex sympathetic discharge in patients who had a spinal cord injury above the splanchnic sympathetic outflow resulting in a sudden increase in blood pressure. Posterior reversible encephalopathy syndrome (PRES) refers to a clinicoradiologic entity characterized by headache, consciousness impairment, visual disturbances, seizures, and posterior transient changes on neuroimaging (cerebral vasogenic edema). Hypertension is a common cause of PRES. The authors describe two case reports of patients with tetraplegia who developed PRES after an autonomic dysreflexia episode. One of them had recurrence of PRES in a similar clinical context. The authors discuss further aspects of PRES and its recurrence, which seems to be unusual particularly after autonomic dysreflexia.

Modified Valsalva test differentiates primary from secondary cough headache

BackgroundThe current definition of cough headache includes provocation of the symptom by Valsalva manoeuvre, and it is generally believed that all cough headache results from a sudden increase in intracranial pressure. We sought to question that presumption and to determine whether the Valsalva test might distinguish primary from secondary cough headache.MethodsWe examined 16 consecutive cough headache patients using a modified Valsalva test (exhalation into the connecting tube of a standard anaeroid sphygmomanometer to 60 mm Hg for 10 seconds). A positive response was recorded if the manoeuvre provoked headache. All patients subsequently underwent brain MRI.ResultsNone of the patients had neurological signs. Eleven had positive modified Valsalva tests. Ten were found subsequently to have posterior fossa pathologies (secondary cough headache: 8 Chiari Type 1 malformations, 2 posterior fossa meningiomas). The cough headache was relieved following surgery in all cases. One patient with a positive Valsalva test had an apparently normal brain MRI but measurements of hindbrain and posterior fossa dimensions were consistent with ‘posterior fossa crowdedness’. The remaining 5 patients had negative (4 patients) or equivocal (1 patient) Valsalva tests and normal MRI scans (primary cough headache).ConclusionsThese findings suggest that secondary cough headache results from a transient increase in intracranial CSF pressure during exertion in the presence of obstruction to normal cerebrospinal fluid dynamics. The modified Valsalva test can also determine whether tonsillar herniation found on brain MRI is symptomatic. Primary cough headache appears to be caused by a different mechanism, possibly through congestion of the orbital venous plexus in the presence of jugular venous incompetence and a reduced threshold for trigeminal sensory activation.

Bronchial obstruction by tumor embolus of contralateral lung during pneumonectomy: report of a case

Bronchial obstruction due to a tumor embolus of the contralateral lung during pneumonectomy is an uncommon and fatal complication. According to previous cases, a bronchial balloon of double-lumen endotracheal tube (DLT) could prevent a dislodged tumor from traveling to the contralateral lung. We experienced a tumor embolism from the bronchus with cancer to the other bronchus despite applying DLT. A 59-year-old male with endobronchial lung cancer underwent a left pneumonectomy. One-lung ventilation was established by the right-sided DLT. After a left bronchial division, a sudden increase of peak airway pressure and reduction of the expired tidal volume to 50 ml was observed. Intraoperative fiberoptic bronchoscopy showed a near total obstruction of the right main bronchus due to tumor emboli. It was not possible to remove the tumor embolus through bronchoscopic suction and forceps. Therefore, we reopened the left bronchial stump and successfully extracted tumor embolus under bronchoscopic guidance.

Boerhaave's Syndrome: Still a Diagnostic and Therapeutic Challenge in the 21st Century.

Boerhaave's syndrome is a rare but potentially fatal condition characterised by a transmural tear of the distal oesophagus induced by a sudden increase in pressure. Diagnosis is challenging as the classic triad of vomiting, abdominal or chest pain, and subcutaneous emphysema is absent in many patients. Management is multidisciplinary and relies on rapid, distinct, and repeated imaging. Treatment has not been standardised and may be conservative, endoscopic, or surgical. We present a typical case which illustrates possible diagnostic pitfalls and the therapeutic conundrum surrounding management of the syndrome. Based on time of presentation and eventual presence of sepsis, a therapeutic algorithm is proposed.

Liquefaction due to the 2006 Yogyakarta Earthquake: Field Occurrence and Geotechnical Analysis

The event of earthquake may induce the occurrence of liquefaction hazard. Liquefaction could cause damage to buildings and infrastructure due to the sudden increase of pore pressure at the loose uncompacted layers causing the loss of support or bearing capacity. The Yogyakarta earthquake on May 27, 2006 of magnitude 6.2 had resulted in liquefaction phenomenon to occur in several affected areas. During this earthquake liquefaction occurrences were observed near the Opak Fault area. Mapping of liquefaction along with geotechnical investigation and analysis had been carried out in Bantul region, Yogyakarta. Geotechnic al investigation consisted of a series of cone penetration tests and drillings was carried out in Patalan region, Bantul, Yogyakarta. Analysis of liquefaction potential was conducted by analyzing CPT data by Robertson and Wride (1989) method. Analysis results revealed that the loose layer consists of silty sand and sandy silt at the depth between 0.2- 12.8 m are potentially liquefied during the earthquake. Results of liquefaction analysis indicated that the thickness of potentially liquefied soil layer vari es between 0.2 -5.2 m and total settlement induced by the liquefaction is varied from 1.0 - 10.8cm concentrated at the middle part of Opak Fault. Geotechnical analysis suggested that the liquefaction had occurred within the upper Quaternary sediment fillin g the Bantulgraben.

Orbital apex cavernous hemangioma – beware of the pear!

Dear Editor, Apically located orbital cavernous hemangiomas (OCHs) are notorious for their detrimental course and problematic management (McNab & Wright 1989). Of a series of 40 histologically proven orbital intraconal OCHs, operated between 1990 and 2010, by four different orbital surgeons in our institutions, 36 OCHs were completely removed within their capsula. All 36 excisions had a satisfying outcome. All these lesions appeared apple shaped and were located in the middle or anterior part of the orbit. Four apically located, pear-shaped OCHs, however, had a disappointing outcome. We here describe these cases and speculate about the causes of the surgical failure. Four otherwise healthy persons (three Caucasians, one Chinese; three women, one man), ranging in age from 37 to 60 years, with progressive visual loss (preoperative visual acuities were 0.5, 0.25, LP+ and 1.2) and/or extensive and progressive visual field defects (in all) underwent a lateral or anterior orbitotomy because of an apically located OCH. All tumours were partially removed after opening of the capsula in a piecemeal fashion. Three of them developed a retrobulbar bleeding during extubation, for which the orbits were reopened. The operation in the 4th patient, a 44-year-old woman, was complicated by profuse bleeding necessitating repeated bipolar coagulation. Final visual acuity was finger counting in 3 and no light perception in one. The incidence, clinical presentation and characteristics of orbital OCHs are nowadays well known (McNab & Wright 1989). Discussion remains on the origin of OCHs and how to deal with apically located representatives. Most OCHs present in the lateral part of the middle third of the orbit, which area is rich of vascular structures. In this region, OCHs can grow by easily pushing aside other structures (Harris 2010). These are easily accessible by an anterior or lateral orbitotomy and can be removed with subtle traction using, for instance, a cryocoagulation probe. It is this kind of OCH that has an apple shape on scans. In contrast, OCHs in the orbital apex, having a pear-shaped configuration, show a different growth pattern, in which the surrounding capsula fuses with adjacent vessels and nerves in an early stage of the disease. Total removal by orbitotomy is impeded by poor visualization, lack of manoeuvring space, excessive bleeding by traction and disruption of blood vessels, damaging of nerve vessels and the ciliary ganglion. Partial removal with or without bipolar cautery shrinkage has been suggested as an alternative procedure (McNab & Wright 1989; Harris 2010). Our experience does not support this option. Although histologic proof and size reduction was the goal of surgery in apical OCHs and these tumours were approached with minimal traction, significant bleeding during or shortly after the operation necessitated reopening of the wounds. Anaesthetic data showed no sudden increase in systemic blood pressure during or immediately after surgery. Unlike in more anteriorly located OCHs, in which the complete lesion can be removed within their capsula, the disruption of the lesion’s capsula in our four patients may be the explanation of the bleeding during or after surgery. Apparently, at least in our hands, a piecemeal OCH excision is not a viable option. Irradiation (Khan et al. 2009; Rootman et al. 2012) or a combined neurosurgical/endoscopic (Locatelli et al. 2011.) orbital approach (using neuronavigation) with microdissection and the use of an operation microscope may be better options to treat these lesions. Larger series, however, are needed to confirm this assumption.

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Study on Liquid Pipeline Water Hammer and Protective Device with Gas Concentration

When pressure is low enough in pipeline the transported liquid vaporizes, and air can be let into the pipeline for various of reasons. After the pipeline is shut down, the air/vapor will gather and cavitation occurs. The existence of cavity in liquid pipeline is harmful when restarting the pipeline because the downstream equipments may not work properly. When the cavity collapse, the unsteady flow pattern in pipeline may be intensified due to the sudden increase of pressure and temperature, which may cause serious accidents. Analysis and calculation for the hydraulic status in gas concentrated liquid pipeline are presented in this paper using the rigid liquid column theory. A new type of protective device which automatically let in and release gas is designed by the author. The device is awarded the national patent of utility model.

Transduction of pressure signal to electrical signal upon sudden increase in turgor pressure in Chara corallina

By taking advantage of large cell size of Chara corallina, we analyzed the membrane depolarization induced by decreased turgor pressure (Shimmen in J Plant Res 124:639-644, 2011). In the present study, the response to increased turgor pressure was analyzed. When internodes were incubated in media containing 200 mM dimethyl sulfoxide, their intracellular osmolality gradually increased and reached a steady level after about 3 h. Upon removal of dimethyl sulfoxide, turgor pressure quickly increased. In response to the increase in turgor pressure, the internodes generated a transient membrane depolarization at its nodal end. The refractory period was very long and it took about 2 h for full recovery after the depolarizing response. Involvement of protein synthesis in recovery from refractoriness was suggested, based on experiments using inhibitors.

Myocardial Infarction Increases Sympathetic Tone and Reduces Baroreflex Sensitivity in Ambulatory Canines

Background Baroreflex sensitivity (BRS) is thought to be a marker of the capability to reflexly increase vagal activity and to decrease sympathetic activity in response to a sudden increase in blood pressure. We developed a novel technique to measure BRS and autonomic nerve activity in ambulatory canines to test the hypothesis that myocardial infarction (MI) reduces BRS by increasing the sympathetic tone. Methods Telemetric devices were implanted into 4 canines to measure systolic arterial pressure (SAP), stellate ganglion (SGNA), and left vagus nerve activities (VNA). The BRS was measured using a sequence method by calculating the linear regression of changes in R-R interval (dR-R) over changes in systolic arterial pressure (dSAP) in episodes with consecutive increase or decrease of SAP for more than 3 beats. Data from 10-minute segments were taken for each hour and averaged over a 24-hour period. BRS and NA values were calculated for all 4 canines at baseline and 9–14 days after induction of an MI by foam embolization of the left anterior descending artery. Results Mean BRS was 22 ± 7 ms/mm Hg at baseline and decreased in post-MI to 16 ± 6 ms/mm Hg (P = .015). The average change in R-R interval over each sequence also decreased in each canine from 381 ms ± 106 to 290 ms ± 110 (P = .003). The average change in SAP over each sequence between baseline and post-MI was not significant (P = .40). When analyzing post-MI BRS at different levels of nerve activity, as episodic SGNA increased from <5.0 mV (3.9 ± 0.5 mV) to >25.0 mV (32.2 ± 2.2 mV), BRS decreased from 20 ± 6 ms/mm Hg to 8 ± 4 ms/mm Hg (P = .046). As the SGNA/VNA ratio increased from <1.0 (.93 ± .01) to >2.0 (2.76 ± .29), post-MI BRS decreased from 18 ± 6 ms/mm Hg to 5 ± 2 ms/mm Hg (P = .006). There were no significant BRS changes associated with different VNA levels. At the same episodic SGNA, VNA, and SGNA/VNA ratios, post-MI BRS was significantly lower than baseline. Conclusions MI reduces BRS in ambulatory canines, and BRS is decreased at higher levels of SGNA and SGNA/VNA ratio. However, BRS does not correlate with VNA. These findings indicate that BRS is determined by sympathetic but not vagal tone. Baroreflex sensitivity (BRS) is thought to be a marker of the capability to reflexly increase vagal activity and to decrease sympathetic activity in response to a sudden increase in blood pressure. We developed a novel technique to measure BRS and autonomic nerve activity in ambulatory canines to test the hypothesis that myocardial infarction (MI) reduces BRS by increasing the sympathetic tone. Telemetric devices were implanted into 4 canines to measure systolic arterial pressure (SAP), stellate ganglion (SGNA), and left vagus nerve activities (VNA). The BRS was measured using a sequence method by calculating the linear regression of changes in R-R interval (dR-R) over changes in systolic arterial pressure (dSAP) in episodes with consecutive increase or decrease of SAP for more than 3 beats. Data from 10-minute segments were taken for each hour and averaged over a 24-hour period. BRS and NA values were calculated for all 4 canines at baseline and 9–14 days after induction of an MI by foam embolization of the left anterior descending artery. Mean BRS was 22 ± 7 ms/mm Hg at baseline and decreased in post-MI to 16 ± 6 ms/mm Hg (P = .015). The average change in R-R interval over each sequence also decreased in each canine from 381 ms ± 106 to 290 ms ± 110 (P = .003). The average change in SAP over each sequence between baseline and post-MI was not significant (P = .40). When analyzing post-MI BRS at different levels of nerve activity, as episodic SGNA increased from <5.0 mV (3.9 ± 0.5 mV) to >25.0 mV (32.2 ± 2.2 mV), BRS decreased from 20 ± 6 ms/mm Hg to 8 ± 4 ms/mm Hg (P = .046). As the SGNA/VNA ratio increased from <1.0 (.93 ± .01) to >2.0 (2.76 ± .29), post-MI BRS decreased from 18 ± 6 ms/mm Hg to 5 ± 2 ms/mm Hg (P = .006). There were no significant BRS changes associated with different VNA levels. At the same episodic SGNA, VNA, and SGNA/VNA ratios, post-MI BRS was significantly lower than baseline. MI reduces BRS in ambulatory canines, and BRS is decreased at higher levels of SGNA and SGNA/VNA ratio. However, BRS does not correlate with VNA. These findings indicate that BRS is determined by sympathetic but not vagal tone.

Inhibition of Autonomic Storm by Epidural Anesthesia Does Not Influence Cardiac Inflammatory Response After Brain Death in Rats

BackgroundAfter brain death (BD) donors usually experience cardiac dysfunction, which is responsible for a considerable number of unused organs. Causes of this cardiac dysfunction are not fully understood. Some authors argue that autonomic storm with severe hemodynamic instability leads to inflammatory activation and myocardial dysfunction. ObjectivesTo investigate the hypothesis that thoracic epidural anesthesia blocks autonomic storm and improves graft condition by reducing the inflammatory response. MethodsTwenty-eight male Wistar rats (250–350 g) allocated to four groups received saline or bupivacaine via an epidural catheter at various times in relation to brain-death induction. Brain death was induced by a sudden increase in intracranial pressure by rapid inflation of a ballon catheter in the extradural space. Blood gases, electrolytes, and lactate analyses were performed at time zero, and 3 and 6 hours. Blood leukocytes were counted at 0 and 6 hours. After 6 hours of BD, we performed euthanasia to measure vascular adhesion molecule (VCAM)-1, intracellular adhesion molecule (ICAM)-1, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, Bcl-2 and caspase-3 on cardiac tissue. ResultsThoracic epidural anesthesia was effective to block the autonomic storm with a significant difference in mean arterial pressure between the untreated (saline) and the bupivacaine group before BD (P < .05). However, no significant difference was observed for the expressions of VCAM-1, ICAM-1, TNF-α, IL-1β, Bcl-2, and caspase-3 (P > .05). ConclusionAutonomic storm did not seem to be responsible for the inflammatory changes associated with BD; thoracic epidural anesthesia did not modify the expression of inflammatory mediators although it effectively blocked the autonomic storm.

Pro-thrombotic condition in a woman with peripartum cardiomyopathy treated with bromocriptine and an Impella LP 2.5 heart pump

Pro-thrombotic condition in a woman with peripartum cardiomyopathy treated with bromocriptine and an Impella LP 2.5 heart pump

Tricuspid valve chordal rupture due to airbag injury and review of pathophysiological mechanisms

Blunt trauma to the chest is associated with significant morbidity and mortality. The latter is usually due to an aortic transection, whereas the former is related to myocardial contusion, cardiac valve injury, coronary artery disruption and intracardiac shunts due to the formation of septal defects. The main mechanisms causing these injuries are due to the sudden deceleration force and compression within the chest cavity. Moreover, there is also the sudden increase in intravascular pressure due to a mechanical compression effect and a hormonal adrenergic surge during the event. We report a case of a tricuspid valve injury caused by the deployment of the airbag during a high-speed impact car accident and the subsequent damage to the tricuspid valve chordal mechanism. The patient's management and the pathophysiological mechanisms involved in the injury are reviewed.

Dynamic modeling of cusp ion structures

Dispersed ion structures observed near the magnetosphere cusps have long been used to infer locations and properties of reconnection at the Earth's magnetopause. However, observations are often difficult to interpret since spacecraft move relative to a cusp ion structure, creating temporal and spatial ambiguity in the observations. Models of cusp ion structures are also limited to the cases during stable solar wind and interplanetary magnetic field (IMF) because empirical models are used to obtain the Earth's electromagnetic fields. We introduce a new model of a cusp ion structure by using the Liouville theorem particle tracer (LTPT) with the OpenGGCM 3D global MHD model. The OpenGGCM produces time‐dependent magnetospheric electromagnetic fields under various solar wind and IMF conditions, while the LTPT traces test particles backward from an observation point to the magnetosheath to map the phase space density and construct an energy‐time spectrogram. This allows our model to study cusp ion structures under dynamic solar wind and IMF conditions. In this paper, we first test our model's capability by reconstructing the cusp ion structures observed from three cusp‐crossing events of Cluster and Polar satellites. We show that the model reproduces various observed ion structures, such as normal dispersion, reverse dispersion, double dispersions, and stepped dispersion. We then show that the cusp structures observed by Cluster on 23 September 2004 and on 23 August 2003 are temporal structures caused by a sudden increase of solar wind dynamic pressure and various reconnection rates, respectively. We also show that the stepped dispersion observed by Polar on 25 August 1998 is not only spatial but also temporal, caused by two different subsolar reconnection sites during a change of the IMF clock angle. In addition, we find that the ions entering the cusp often cross the magnetopause far away from the reconnection site, even though the reconnection is the cause of precipitation, and that the magnetic configuration of the magnetosheath is also sometimes a cause of energy dispersion in a cusp structure.

Active Potassium Supplementation Might Be Mandatory During Laparoscopic Adrenalectomy for Primary Hyperaldosteronism

It is well recognized that monitoring of the serum potassium level during laparoscopic adrenalectomy for primary hyperaldosteronism is critical. Nevertheless, the guideline for prevention and management of hypokalemia during the operation has not been established to date. In this study, we investigated whether active potassium supplementation could prevent electrolyte imbalance during laparoscopic adrenalectomy for primary hyperaldosteronism. From January 2007 to May 2011, 35 patients underwent transperitoneal laparoscopic adrenalectomy for primary hyperaldosteronism (Conn's syndrome). The hemodynamic and electrolyte changes during the operation were recorded serially. In first 10 patients (group A), potassium was replaced passively on demand. Based on this result, potassium was actively supplemented during the operation in the subsequent 25 patients (group B). The perioperative parameters, hemodynamic changes, and serum potassium levels were analyzed and compared between the two groups. The patients' demographic data, initial blood pressure, and serum electrolyte levels were similar in both groups. The operative time was shorter in group B (P=0.035). The mean serum potassium level was decreased by 0.7 mmol/L during the first 30 minutes in group A. Based on this result, potassium was actively supplemented from the beginning of the operation in group B. The mean hypokalemic events were 4 ± 2 in group A. None of the patients in group B, however, experienced hypokalemia. The hemodynamic events (sudden increase of blood pressure) and mean blood pressure changes during the operation were similar in both groups. Our results demonstrate that serum potassium levels are constantly decreasing during laparoscopic adrenalectomy for primary aldosteronism. Active supplementation of potassium during the operation might prevent a hypokalemic event.

About uses of magnesium during perioperative period

About uses of magnesium during perioperative period

Tension Pneumoperitoneum: A Rare Complication of Upper Gastrointestinal Endoscopy

Tension pneumoperitoneum is defined as the massive accumulation of air in the peritoneal cavity, which results in a sudden increase in intraabdominal pressure. Various iatrogenic procedures are responsible for this complication. We herein report a case of tension pneumoperitoneum resulting from upper gastrointestinal endoscopy. A 45-y-old man was referred to our department because of melena. Esophagogastroscopy was unsuccessful because of failure to inflate the stomach, and sudden abdominal distension was noted immediately after the procedure. The hemodynamic status of the patient was compromised, and the imminent collapse was prevented with emergent needle paracentesis. Decompression of the abdominal cavity restored vital signs to normal allowing definitive surgical treatment. Upper gastrointestinal endoscopy is a rare cause of this life-threatening complication. The combination of acute abdominal distension with hemodynamic instability following endoscopic procedures should raise suspicion of tension pneumoperitoneum. Needle decompression is life-saving and should be performed instantly upon recognition of this condition.

Emergency management of hypertension in children.

Systemic arterial hypertension in children has traditionally been thought to be secondary in origin. Increased incidence of risk factors like obesity, sedentary life-styles, and faulty dietary habits has led to increased prevalence of the primary arterial hypertension (PAH), particularly in adolescent age children. PAH has become a global epidemic worldwide imposing huge economic constraint on health care. Sudden acute increase in systolic and diastolic blood pressure can lead to hypertensive crisis. While it generally pertains to secondary hypertension, occurrence of hypertensive crisis in PAH is however rare in children. Hypertensive crisis has been further subclassified depending on presence or absence of end-organ damage into hypertensive emergency or urgency. Both hypertensive emergencies and urgencies are known to cause significant morbidity and mortality. Increasing awareness among the physicians, targeted at investigation of the pathophysiology of hypertension and its complications, better screening methods, generation, and implementation of novel treatment modalities will impact overall outcomes. In this paper, we discuss the etiology, pathogenesis, and management of hypertensive crisis in children. An extensive database search using keywords was done to obtain the information.

Transobturator tension-free “inside-to-out” suburethral sling procedure for the treatment of stress urinary incontinence

Stress urinary incontinence is an involuntary leakage of urine on a sudden increase of intra-abdominal pressure by physical activity, exercise, coughing, sneezing or laughing. To assess symptoms, functional and anatomical status of voiding function, complications and short term success of a novel procedure, tension-free vaginal tape obturator technique (TVT-O) in the treatment of stress urinary incontinence. A prospective study was performed on 40 female patients who underwent the TVT-O suburethral sling at the Urology Department of the Health Centre in Prokuplje and Urology Hospital in Nis between May 2009 and February 2010. The mean patients' age was 58 years (range 34-84 years). Preoperative evaluation included a detailed history and gynaecologic examination including urodynamic testing and voiding studies. UDI-6 and UIQ-7 score testing was performed before, and six months after surgery. All patients who demonstrated stress urinary incontinence with a Q-tip test-angle during maximal straining were included into the study. Postoperatively, outcomes evaluation included voiding function, anatomical parameters, complications, as well as subjective success rates. In 30 patients surgery was performed under spinal and in ten under general anaesthesia. The average intraoperative blood loss during theTVT-O was minimal (<50 ml). There were no vascular, bladder, bowel, and neurological injuries. Thirty-eight patients (95%) were discharged voiding satisfactorily. There was a statistically significant difference in symptoms between UDI-6 and UIQ-7 before and after surgery. Initial experience with TVT-O suburethral sling is promising. The TVT-O differs from retropubic procedures by resulting in lower postoperative morbidity, intraoperative and postoperative complications.