Pelvic Pressure Research Articles

Effect of intrarenal pelvic pressure on pyelo-tubular backflow and renal cortical blood perfusion during mini-percutaneous nephrolithotomy.

To investigate the effects of intrarenal pelvic pressure (IPP) on pyelo-tubular backflow and renal cortical blood perfusion during mini-percutaneous nephrolithotomy (MPCNL). Dynamic changes in pyelo-tubular backflow and renal cortical blood perfusion were studied in six patients undergoing MPCNL using dynamic contrast-enhanced ultrasonography (CEUS) and IPP monitoring. CEUS of intrarenal pelvic perfusion revealed that renal tubules began to exhibit contrast agent reflux when IPP exceeded 34 mmHg during the MPCNL procedure. There was a positive correlation between renal tubule contrast agent reflux and IPP (P < 0.05). Intravenous CEUS of renal cortical blood flow demonstrated that both intrarenal pelvic perfusion time and IPP during MPCNL significantly affected renal cortical blood perfusion. Intrarenal pelvic perfusion time and pressure were negatively correlated with contrast agent peak intensity (PI) and area under the curve (AUC) (P < 0.05). Longer intrarenal pelvic perfusion times and higher pressures resulted in decreased renal cortical blood perfusion. This study directly confirmed through dynamic CEUS and real-time IPP monitoring that an increase in IPP above the threshold of approximately 34 mmHg during MPCNL in patients leads to reflux through the renal tubules and a significant decrease in renal cortical blood perfusion. The safe upper limit for intrarenal pelvic perfusion pressure during MPCNL is approximately 34 mmHg.

Relationship between renal pelvis pressure and post-ureteroscopy infection in a live swine model.

To evaluate the relationship between renal pelvis pressure and infection after ureteroscopy, using a live swine model. In anaesthetised pigs, a 1-h ureteroscopy was performed using a pressure-sensing guidewire, with renal pelvis pressure maintained at either 37 mmHg or 75 mmHg for the entire procedure and infusion with saline alone or with a standardised concentration of uropathogenic Escherichia coli strain CFT073 (1.5 × 107 colony-forming units [CFU]/mL). Venous blood sampling was performed during and after the procedure. Vital signs, inflammatory biomarkers, and renal tissue and blood cultures were assessed. In 21 pig kidneys, study groups were: 37 mmHg with saline irrigation (n = 3); 75 mmHg with saline irrigation (n = 4); 37 mmHg with saline irrigation with 1.5 × 107 CFU/mL E. coli (n = 7); and 75 mmHg with saline irrigation with 1.5 × 107 CFU/mL E. coli (n = 7). Statistically significant changes in inflammatory biomarkers were most pronounced in the group with 75 mmHg saline irrigation + E. coli and were significantly elevated compared with the control group and the group receiving E. coli irrigation at 37 mmHg. Positive blood cultures were noted in 5/7 animals treated with E. coli at 75 mmHg; no others developed bacteraemia. In this swine model of ureteroscopy, irrigation with saline + E. coli at a renal pelvis pressure of 75 mmHg resulted in bacteraemia and inflammatory biomarker elevations significantly greater than both E. coli irrigation with renal pelvis pressure maintained at 37 mmHg and the control.

Feasibility and safety of flexible ureteroscopy with intelligent control of renal pelvis pressure without urinary catheter: a retrospective study

BackgroundTo explore the feasibility and safety of aflexible ureteroscopy with intelligent control of renal pelvic pressure(FUS-ICP) without a post-operative indwelling urinary catheter .MethodsIn this retrospective study, we assessed patients with upper urinary tract stones who were treated with FUS-ICP at the Ganzhou People’s Hospital from February 2022 to December 2023. Patients were divided into the non-urinary catheter (non-UC) and urinary catheter (UC) groups according to whether an indwelling catheter was used after surgery.ResultsIn total, 142 patients were included in the study. There was no significant difference in the preoperative general data between the two groups. Patients in the non-UC group performed better than those in the UC group in terms of catheter-related bladder irritation (P = 0.001), the Sedation-Agitation Scale score (P = 0.012), and the numerical rating scale (P = 0.003). The incidences of urinary retention (P = 0.620), urinary tract infection (P = 0.529), and replacement of urethral catheter s (P = 0.438) in the UC group were inferior to those in the non-UC group, but there was no statistical significance.ConclusionsIt is feasible and safe to perform FUS-ICP without a post-procedure indwelling urinary catheter.

Intelligent control of pressure based on ureteral access sheaths: renal pelvic pressure during flexible ureteroscope perfusion at different sites.

This study aimed to evaluate the accuracy and effectiveness of renal pelvic pressure (RPP) control during flexible ureteroscopic perfusion at various sites. Flexible ureteroscopy for the intelligent control of RPP was based on a ureteral access sheath (UAS) that integrated pressure measurement and suction functions (with automatic adjustment). Eleven consecutive patients with indurating nephrostomy tubes were enrolled. The nephrostomy tube was connected to a disposable invasive blood pressure sensor. The RPP was zeroed after the pressure stabilized. The flow rate and control value were set at 100ml/min and - 5 mmHg, respectively. An 8.5 Fr flexible ureteroscope was irrigated at the renal pelvis, as well as the upper, middle, and lower calyces of the kidney for 1min. All 11 patients with upper urinary tract calculi underwent successful UAS placement. Pressures measured by the sheath and fistula during perfusion were - 5.07 ± 1.41 and - 4.89 ± 1.07 mmHg at the renal pelvis, -5.16 ± 1.36 and - 5.12 ± 1.32 mmHg at the upper calyces, -4.98 ± 0.87 and - 5.39 ± 1.01 mmHg at the middle calyces, as well as -4.95 ± 1.56 and - 5.64 ± 1.24 mmHg at the lower calyces, respectively. There were no significant differences in pressure between the sheath and fistula groups or in sheath and fistula pressures among parts. The RPP fluctuated; however, all values were within the safe limit of 20 mmHg. The UAS-based pressure monitoring technology can accurately and reliably monitor and control RPP within a set range.

Presurgical treatment of uterine myomas with the GnRH-antagonist relugolix in combination therapy: an observational study.

To evaluate if a preoperative medical treatment with the GnRH-antagonist relugolix in combination therapy in a series of patients with abnormal uterine bleeding associated with uterine myomas may correct the anemia before scheduled surgery for myoma-associated AUB. Thirty-one patients scheduled for surgery underwent a pre-operative three-month course with a daily oral tablet of 40mg relugolix, 1mg estradiol, and 0.5mg norethindrone acetate. Hemoglobin levels, uterine volumes, largest myoma diameter, and VAS score for dysmenorrhea, pelvic pressure and bleeding discomfort, and indication to surgery were evaluated at study enrollment and at the end of therapy. Mean hemoglobin levels increased by 25%, from 9.3 ± 1.1 to 11.6 ± 1.7g/dL after three months (p < 0.001). Uterine volume decreased from 380.7 ± 273.4 mL to 281.7 ± 198.7 mL (p < 0.001), whereas the diameter of the largest myoma decreased from 6.4 ± 2.8cm to 5.5 ± 2.2cm (p < 0.001). Four patients (13%), initially planned for a laparotomy procedure, were converted to a minimally-access procedure, whereas in eight patients (26%) surgery was avoided after medical therapy. Dysmenorrhea score improved from 4.7 ± 3.2 to 0.6 ± 1.1 (p < 0.0001). Pelvic pressure score decreased from 5.9 ± 2.1 to 3.1 ± 2.3 (p < 0.0001), whereas bleeding discomfort decreased from 7.4 ± 3.0 to 0.4 ± 1.6 (p < 0.0001). Preoperative GnRH-antagonist therapy may enhance hemoglobin levels, decrease uterine and myoma size, and alleviate symptoms, potentially enabling safe surgical procedures.

Assessment of the pelvic and body interface pressure during different recumbent and semi-recumbent birthing positions

BackgroundChildbirth, a multifaceted physiological event, undergoes dynamic changes influenced significantly by the chosen birthing position, impacting comfort and maternal and neonatal outcomes among other factors. This study aimed to investigate the bed-body interface pressure across five commonly adopted birthing positions, particularly focusing on their influence on pelvic expansion biomechanics during labour. MethodsTwenty healthy participants, aged between 18 and 49 years, were evaluated. Interface pressure across multiple regions of interest, including the head, shoulder, pelvis, and full body, were meticulously assessed under different combinations of leg and back positioning. FindingsSignificant variations in interface pressure were observed based on chosen positions. Post hoc pairwise comparisons showed different pressure distributions for all regions of interest, with the combination of legs in stirrups and a flat back resulting in the lowest average pressure in the pelvic region. During the closed glottis pushing task, this combination exhibited lower peak pressure and peak pressure index in the pelvic region compared to other positions. InterpretationWhile upright positions are conventionally preferred, the study underscores the nuanced implications of recumbent and semi-recumbent positions. Although using stirrups with a flat back exerts less pressure, lying flat can impede blood flow and exacerbate pain, while stirrups might lead to discomfort and potential complications. Given these complexities, healthcare providers must consider multiple factors to determine optimal birthing positions. The interplay between birthing positions and obstetric outcomes awaits further exploration and refinement, marking an exciting frontier in maternal care.

Highly-sensitive ultrathin flexible pressure sensor based on quasi-2D conductive network for human physiological signal monitoring

Ultrathin flexible pressure sensors are highly desirable for human physiological signal monitoring due to their portability and ability to conform to the body. However, existing ultrathin pressure sensors face challenges in balancing the sensitivity and their range. A spatial-dimensionally constrained strategy was proposed to construct an ultrathin active layer. In detail, multi-walled carbon nanotubes (MWCNTs) with an average length of ∼1.3 μm were intentionally spin-coated into a thin thermoplastic polyurethane (TPU) film with a thickness of 1.5 μm. By doing so, a quasi-2D MWCNTs conductive network is constructed, which enabled the sensor to have ultrahigh sensitivity of 27.04 kPa−1, a wide liner detection range of 0.2–24 kPa, ultrafast response time of 40 ms and a recovery time of 10 ms, and high durability in 1500 cycles under 0.2 kPa with loading/unloading frequency of 2 Hz. Thanks to this superior performance, the ultrathin pressure sensor can be used to monitor human movement and physiological signals, including finger touch, finger bending, wrist bending, and deep breathing. Moreover, the sensor can be attached to the side wall of the tip of the renal ureteroscope, allowing for the monitoring of renal pelvic pressure. Therefore, this spatial-dimensionally constrained strategy will open up a new way to fabricate highly sensitive ultrathin pressure sensors and have great application prospects in health monitoring.

The impact of siphoning effect on renal pelvis pressure during ureteroscopy using an in vitro kidney and ureter model.

To experimentally measure renal pelvis pressure (PRP) in an ureteroscopic model when applying a simple hydrodynamic principle, the siphoning effect. A 9.5Fr disposable ureteroscope was inserted into a silicone kidney-ureter model with its tip positioned at the renal pelvis. Irrigation was delivered through the ureteroscope at 100cm above the renal pelvis. A Y-shaped adapter was fitted onto the model's renal pelvis port, accommodating a pressure sensor and a 4 Fr ureteral access catheter (UAC) through each limb. The drainage flowrate through the UAC tip was measured for 60s each run. The distal tip of the UAC was placed at various heights below or above the center of the renal pelvis to create a siphoning effect. All trials were performed in triplicate for two lengths of 4Fr UACs: 100cm and 70cm (modified from 100cm). PRP was linearly dependent on the height difference from the center of the renal pelvis to the UAC tip for both tested UAC lengths. In our experimental setting, PRP can be reduced by 10 cmH20 simply by lowering the distal tip of a 4 Fr 70cm UAC positioned alongside the ureteroscope by 19.7cm. When using a 4 Fr 100cm UAC, PRP can drop 10 cmH20 by lowering the distal tip of the UAC 23.3cm below the level of the renal pelvis. Implementing the siphoning effect for managing PRP during ureteroscopy could potentially enhance safety and effectiveness.

In Vitro and In Vivo Drug Release from a Nano-Hydroxyapatite Reinforced Resorbable Nanofibrous Scaffold for Treating Female Pelvic Organ Prolapse.

Pelvic prolapse stands as a substantial medical concern, notably impacting a significant segment of the population, predominantly women. This condition, characterized by the descent of pelvic organs, such as the uterus, bladder, or rectum, from their normal positions, can lead to a range of distressing symptoms, including pelvic pressure, urinary incontinence, and discomfort during intercourse. Clinical challenges abound in the treatment landscape of pelvic prolapse, stemming from its multifactorial etiology and the diverse array of symptoms experienced by affected individuals. Current treatment options, while offering relief to some extent, often fall short in addressing the full spectrum of symptoms and may pose risks of complications or recurrence. Consequently, there exists a palpable need for innovative solutions that can provide more effective, durable, and patient-tailored interventions for pelvic prolapse. We manufactured an integrated polycaprolactone (PCL) mesh, reinforced with nano-hydroxyapatite (nHA), along with drug-eluting poly(lactic-co-glycolic acid) (PLGA) nanofibers for a prolapse scaffold. This aims to offer a promising avenue for enhanced treatment outcomes and improved quality of life for individuals grappling with pelvic prolapse. Solution extrusion additive manufacturing and electrospinning methods were utilized to prepare the nHA filled PCL mesh and drug-incorporated PLGA nanofibers, respectively. The pharmaceuticals employed included metronidazole, ketorolac, bleomycin, and estrone. Properties of fabricated resorbable scaffolds were assessed. The in vitro release characteristics of various pharmaceuticals from the meshes/nanofibers were evaluated. Furthermore, the in vivo drug elution pattern was also estimated on a rat model. The empirical data show that nHA reinforced PCL mesh exhibited superior mechanical strength to virgin PCL mesh. Electrospun resorbable nanofibers possessed diameters ranging from 85 to 540 nm, and released effective metronidazole, ketorolac, bleomycin, and estradiol, respectively, for 9, 30, 3, and over 30 days in vitro. Further, the mesh/nanofiber scaffolds also liberated high drug levels at the target site for more than 28 days in vivo, while the drug concentrations in blood remained low. This discovery suggests that resorbable scaffold can serve as a viable option for treating female pelvic organ prolapse.

Prediction of myofascial pelvic pain syndrome based on random forest model

The objective is to construct a random forest model for predicting the occurrence of Myofascial pelvic pain syndrome (MPPS) and compare its performance with a logistic regression model to demonstrate the superiority of the random forest model. We retrospectively analyze the clinical data of female patients who underwent pelvic floor screening due to chronic pelvic pain at the Pelvic Floor Rehabilitation Center of the Third Affiliated Hospital of Zhengzhou University from January 2021 to December 2023. A total of 543 female patients meeting the study's inclusion and exclusion criteria are randomly selected from this dataset and allocated to the MPPS group. Furthermore, 702 healthy female patients who underwent pelvic floor screening during routine physical examinations within the same timeframe are randomly selected and assigned to the non-MPPS group. Chi-square test and rank-sum test are used to select demographic variables, pelvic floor pressure assessment data variables, and modified Oxford muscle strength grading data for logistic univariate analysis. The selected variables are further subjected to multivariate logistic regression analysis, and a random forest model is also established. The predictive performance of the two models is evaluated by comparing their accuracy, sensitivity, specificity, precision, receiver operating characteristic (ROC) curve, and area under the curve (AUC) area. Based on a dataset of 1245 cases, we implement the random forest algorithm for the first time in the screening of MPPS. In this investigation, the Logistic regression model forecasts the accuracy, sensitivity, specificity, and precision of MPPS at 69.96%, 57.46%, 79.63%, and 68.57% respectively, with an AUC of the ROC curve at 0.755. Conversely, the random forest prediction model exhibits accuracy, sensitivity, specificity, and precision rates of 87.11%, 90.66%, 90.91%, and 83.51% respectively, with an AUC of the ROC curve at 0.942. The random forest model showcases exceptional predictive performance during the initial screening of MPPS. The random forest model has exhibited exceptional predictive performance in the initial screening evaluation of MPPS disease. The development of this predictive framework holds significant importance in refining the precision of MPPS prediction within clinical environments and elevating treatment outcomes. This research carries profound global implications, given the potentially elevated misdiagnosis rates and delayed diagnosis proportions of MPPS on a worldwide scale, coupled with a potential scarcity of seasoned healthcare providers. Moving forward, continual refinement and validation of the model will be imperative to further augment the precision of MPPS risk assessment, thereby furnishing clinicians with more dependable decision-making support in clinical practice.

The effectiveness of relugolix compared with leuprorelin for preoperative therapy before laparoscopic myomectomy in premenopausal women, diagnosed with uterine fibroids: protocol for a randomized controlled study (MyLacR study)

BackgroundThe oral gonadotropin-releasing hormone antagonist relugolix, which temporarily stops menstruation, is used to treat heavy menstrual bleeding, pelvic pressure, and low back pain in women with uterine fibroids. Treatment can also help women recover from low hemoglobin levels and possibly shrink the fibroids. However, evidence of preoperative use of relugolix before laparoscopic myomectomy is limited. Nevertheless, the treatment could reduce interoperative blood loss, decrease the risk of developing postoperative anemia, and shorten the operative time. Thus, we aim to test whether 12-week preoperative treatment with relugolix (40 mg orally, once daily) is similar to or not worse than leuprorelin (one injection every 4 weeks) to reduce intraoperative blood loss.MethodsEfficacy and safety of preoperative administration of drugs will be studied in a multi-center, randomized, open-label, parallel-group, noninferiority trial enrolling premenopausal women ≥ 20 years of age, diagnosed with uterine fibroids and scheduled for laparoscopic myomectomy. Participants (n = 80) will be recruited in the clinical setting of participating institutions. The minimization method (predefined factors: presence or absence of fibroids ≥ 9 cm and the International Federation of Gynecology and Obstetrics [FIGO] type 1–5 fibroids) with randomization is used in a 1:1 allocation. Relugolix is a 40-mg oral tablet taken once a day before a meal, for 12 weeks, up to the day before surgery. Leuprorelin is a 1.88 mg, or 3.75 mg subcutaneous injection, given in three 4-week intervals during patient visits before the surgery. For the primary outcome measure of intraoperative bleeding, the blood flow is collected from the body cavity, surgical sponges, and collection bag and measured in milliliters. Secondary outcome measures are hemoglobin levels, myoma size, other surgical outcomes, and quality-of-life questionnaire responses (Kupperman Konenki Shogai Index and Uterine Fibroid Symptoms—Quality of Life).DiscussionReal-world evidence will be collected in a clinical setting to use pre-treatment with an oral gonadotropin-releasing hormone antagonist to reduce intraoperative bleeding in women who undergo laparoscopic myomectomy.Trial registrationjRCTs031210564 was registered on 19 January 2022 in the Japan Registry of Clinical Trials (https://jrct.niph.go.jp).

Fluid absorption during flexible ureteroscopy with intelligent control of renal pelvic pressure: a randomized controlled trial.

To investigate fluid absorption and its influencing factors during flexible ureteroscopy with intelligent control of renal pelvic pressure (RPP). A total of 80 patients with upper urinary tract calculi underwent flexible ureteroscopy with intelligent control of RPP by pressure-measuring ureteral access sheath and were randomly divided into four groups. The RPP of Groups A, B, and C were set at -5, 0 and 5mmHg, respectively. Conventional flexible ureteroscopy with uncontrolled pressure served as control Group D. The perfusion flow rate was set at 100ml/min in the four groups, with 20 patients in each group. The fluid absorption was measured by 1% ethanol every 10min. Operation time, stone-free rate, and complications were recorded. Seventy-three patients were finally included in the RCT. The general and preoperative data of the patients were comparable between the groups. The fluid absorption of Groups A, B, and C was significantly less than that of Group D (P < 0.01). Fluid absorption and operation time were positively correlated, and the correlation coefficients R were 0.864, 0.896, 0.918, and 0.947, respectively (P < 0.01). The fluid absorption of patients with vomiting, fever and ureteral injury was greater than that of patients without complications in the four groups (P < 0.01). In different groups, fluid absorption was greater in patients with ureteral injury Post-Ureteroscopic Lesion Scale (PULS) 1-3 than in noninjured patients (P < 0.01). Flexible ureteroscopy with intelligent control of RPP effectively reduces the absorption of perfusion fluid. Operation time and ureteral injury are also key factors affecting perfusion fluid absorption. NCT05201599; August 11, 2021.

Flexible Ureteroscopy with a Tip-Flexible Pressure-Controlling Ureteral Access Sheath for Renal Stones in Children

Introduction: The aim of this study was to evaluate the safety and efficacy of flexible ureteroscopy using a tip-flexible pressure-controlling ureteral access sheath (TFPC-UAS) for renal stones in children. Methods: Consecutive patients aged 5–18 years with renal stones of diameter 1–3 cm were enrolled between January 2022 and November 2023 at Ganzhou People’s Hospital. The patients were treated with flexible ureteroscopy using the TFPC-UAS. The renal pelvic pressure (RPP) parameters were set as follows: control value at −10 mm Hg to 5 mm Hg, warning value at 20 mm Hg, and limit value at 30 mm Hg. The infusion flow rate was set to 100–120 mL/min. A holmium laser (276 μm) was used to fragment the stone at 2.0–2.5 J/pulse with a frequency of 20–30 pulses/s. The cases were analyzed for RPP, operative time, stone-free rate, and complications. Results: A total of 21 consecutive patients were included. Two patients were switched to percutaneous nephrolithotomy owing to sheath placement failure. The RPP was −4.6 ± 2.1 mm Hg. The mean operative time was 56.5 ± 17.1 min. The postoperative hospitalization time was 1.5 ± 0.3 days. The stone-free rates at 1 day and 1 month after surgery were 81.0% and 85.7%, respectively. Residual stones in 2 patients were cleared after extracorporeal shockwave lithotripsy. Three cases of Clavien I complications and one case of Clavien II complications occurred. No major complications (Clavien grade III–V) were observed. Conclusions: Flexible ureteroscopy with a TFPC-UAS is safe and effective for renal stones in children.

Nomogram including renal pelvic pressure to predict the occurrence of urosepsis following percutaneous nephrolithotomy: a dual center retrospective study of 1,448 patients

Nomogram including renal pelvic pressure to predict the occurrence of urosepsis following percutaneous nephrolithotomy: a dual center retrospective study of 1,448 patients

Bacterial Contamination Control with Sodium Hypochlorite and Jet Lavage Irrigation in a Severe Stage 4 Pelvic Pressure Injury: A Case Report.

This case report reviews the effect of combining a 250-cc bottle of standard antimicrobial, buffered sodium hypochlorite with a surgical method, low-pressure jet lavage irrigation in the outpatient setting to control difficult wound contamination. A 73-year-old man had been in treatment for over 8 years, undergoing at least 18 surgical wound debridement procedures for an extensive undermined pelvic pressure injury involving the sacrum, ischium, and greater trochanter. Cultures and polymerase chain reaction diagnostics revealed a multibacterial presence. Autofluorescent imaging (AFI) was used in 21 examinations performed after a 72-hour delay over a long weekend. The AFI contamination exceeded log 4 colony-forming units/g of tissue in all pretreatment examinations and was reduced to less than log 2 colony-forming units in 6 of 21 examinations, with the remaining 15 showing an estimated 80% or higher removal of the bacterial porphyrin "red" appearance. A total of 54 AFI examinations were performed using the combination treatment, and no adverse reactions were encountered. Treatment paradigms can be improved with a multifactorial approach.

Prone vs supine percutaneous nephrolithotomy: does position affect renal pelvic pressures?

The purpose of this study was to measure and compare renal pelvic pressure (RPP) between prone and supine percutaneous nephrolithotomy (PCNL) in a benchtop model. Six identical silicone kidney models were placed into anatomically correct prone or supine torsos constructed from patient CT scans in the corresponding positions. A 30-Fr renal access sheath was placed in either the upper, middle, or lower pole calyx for both prone and supine positions. Two 9-mm BegoStones were placed in the respective calyx and RPPs were measured at baseline, irrigating with a rigid nephroscope, and irrigating with a flexible nephroscope. Five trials were conducted for each access in both prone and supine positions. The average baseline RPP in the prone position was significantly higher than the supine position (9.1 vs 2.7 mmHg; p < 0.001). Similarly, the average RPP in prone was significantly higher than supine when using both the rigid and flexible nephroscopes. When comparing RPPs for upper, middle, and lower pole access sites, there was no significant difference in pressures in either prone or supine positions (p > 0.05 for all). Overall, when combining all pressures at baseline and with irrigation, with all access sites and types of scopes, the mean RPP was significantly higher in the prone position compared to the supine position (14.0 vs 3.2 mmHg; p < 0.001). RPPs were significantly higher in the prone position compared to the supine position in all conditions tested. These differences in RPPs between prone and supine PCNL could in part explain the different clinical outcomes, including postoperative fever and stone-free rates.

Effect of nephrostomy sheath size on renal pelvic pressure during endoscopic combined intrarenal surgery: artificial kidney model study

BackgroundThis study aimed to evaluate the intrarenal pelvic pressure in endoscopic combined intrarenal surgery using an artificial kidney model.MethodsAn artificial kidney model was created using the Urovac evacuator™. Four sizes of nephrostomy sheaths (MIP-L: 25/26 Fr, MIP-M: 16.5/17.5 Fr, MIP-S: 11/12 Fr, MIP-XS: 8.5/9.5 Fr) and two sizes of ureteral access sheaths (12/14 Fr and 10/12 Fr) were installed into the model. For each combination of nephrostomy and ureteral access sheath, renal pelvic pressure was measured with and without insertion of the retrograde flexible ureteroscope. Irrigation from the nephroscope was adjusted to 40–160 mmHg using an automatic irrigation device, and the irrigation of the ureteroscope was by spontaneous dripping at 80 cmH2O. Conditions were measured six times, and the renal pelvic pressure was compared in different conditions.ResultsWithout ureteroscope insertion through the ureteral access sheath, the renal pelvic pressure never exceeded 30 mmHg. Meanwhile, when the ureteroscope was inserted, the renal pelvic pressure increased as the nephrostomy sheath and ureteral access sheath became narrower and as the irrigation pressure increased. Intrarenal pelvic pressure exceeded 30 mmHg when the irrigation pressure was increased in 12/14 Fr ureteral access sheath when MIP-XS was used, and in 10/12 Fr ureteral access sheath when MIP-XS and MIP-S were used.ConclusionsThe use of a thin nephrostomy sheath in endoscopic combined intrarenal surgery can lead to increased intrarenal pelvic pressure. Although our results are from an artificial kidney model, special care is suggested to be required when using a retrograde flexible ureteroscope simultaneously in treatment of patients.

A clinical study of surgical management of pelvic girdle pressure sores: a three-year experience

Introduction It is critical to categorize pressure ulcers at different stages to establish effective treatment plans. Debridement and excision of the underlying bursa and implicated bone tissue, followed by tissue covering, are the basic surgical procedures. This research examines patient characteristics, results, and complications, reporting on our experience treating pressure ulcers. Methods All the 25 individuals had a total of 39 pressure ulcers treated. The sacral ulcer was the most common. Three-quarters of the cases were related to pressure ulcer formation in hospitals. Debridement, primary repair, skin grafts, V-Y fasciocutaneous flap, transverse lumbar fasciocutaneous flap, V-Y tensor fascia lata flap, inferior gluteal rotational myocutaneous flap, and V-Y gluteal myocutaneous flap were among the available treatment options. Results Complications happened in 19%. Most of the time, pressure ulcers may be prevented with adequate understanding of their etiology and appropriate patient treatment for those who are at risk. Given the frequency of complications, recurrence, and new ulcers, treatment of individuals with pressure ulcers requires multidisciplinary involvement as well as family involvement. For the best prognosis and appropriate closure of the ulcer, complications and risk factors such as poor hygiene, anemia, diabetes, infection, and hypoalbuminemia should be avoided. Conclusion In the medical sector as a whole, pressure sores are a prevalent issue. The pelvic girdle pressure points appear to be the focus of most sores. Medical personnel who are in charge of patient monitoring must be knowledgeable about the main risk factors.

The optimal ratio of endoscope-sheath diameter with negative-pressure ureteral access sheath: an in vitro research.

To maintain safe intrarenal pelvic pressure (IPP), the combination of flexible ureteroscope (fURS) and traditional ureteral access sheath (T-UAS) should maintain a basic rule that is the ratio of endoscope-sheath diameter (RESD) ≤ 0.75. However, the negative-pressure ureteral access sheath (NP-UAS) may break the rule of negative pressure suction. This study aimed to examine the effect of NP-UAS on IPP and flow rate (FR) with varying RESD. In a 3D-printed renal model, flexible ureteroscopy lithotripsy (fURL) was replicated. Six sizes of fURS paired with 12Fr T-UAS and NP-UAS resulted in six distinct RESDs of 0.63, 0.78, 0.87, 0.89, 0.90, and 0.91. While the irrigation pressure (IRP) was set between 100 and 800 cmH2O and the sucking pressure (SP) was set between 0 and 800 cmH2O, the IPP and FR were measured in each RESD. NP-UASs can reduce the IPP and increase the FR at the same RESD compared to T-UASs. The IPP decreased with increasing SP with NP-UAS. When RESD ≤ 0.78, T-UAS and NP-UAS can maintain IPP < 40 cmH2O in most circumstances. When RESD = 0.87, it is challenging for T-UAS to sustain IPP < 40 cmH2O; however, NP-UAS can do so. When RESD ≥ 0.89, it is difficult to maintain an IPP < 40 cmH2O even with NP-UAS. NP-UAS can decrease IPP and increase FR compared with T-UAS. To maintain a safe IPP, it is recommended that RESD < 0.85 when utilizing NP-UAS.

Experimental study of a new technique for minimally invasive percutaneous nephrolithotomy: intelligent pressure-controlled minimally invasive percutaneous nephrolithotomy

BackgroundTo test the reliability and safety of a newly invented technique for minimally invasive percutaneous nephrolithotomy, intelligent pressure-controlled minimally invasive percutaneous nephrolithotomy (IPC-MPCNL).MethodsEighteen kidneys of nine female pigs were randomly divided into three groups. Those in Groups A and B underwent IPC-MPCNL through the new system composed of a pressure-measuring MPCNL suctioning sheath and an irrigation and suctioning platform with pressure feedback control. The infusion flow rate was 500 ml/min in Group A and 750 ml/min in Group B. Those in Group C underwent MPCNL at an infusion flow rate of 500 ml/min. The renal pelvic pressure (RPP) monitored by a ureteral catheter and that monitored by the pressure-measuring sheath in Groups A and B were compared. The RPP in Group C was monitored by a ureteral catheter.ResultsThe RPP measured by the pressure-measuring sheath and that measured by the ureteral catheter in Group A was − 5.59 ± 1.95 mmHg and 4.46 ± 2.08 mmHg, respectively. The RPP measured by the pressure-measuring sheath and that measured by the ureteral catheter in Group B was − 4.00 ± 2.01 mmHg and 5.92 ± 2.05 mmHg, respectively. Hence, the RPPs measured by the pressure-measuring sheath in Groups A and B were consistent with those measured by the ureteral catheter. The RPP in Group C was 27.75 ± 5.98 mmHg (large fluctuations).ConclusionsIPC-MPCNL can be used to accurately monitor the RPP and maintain it within a preset safe range via suction. The new technique and the new system are safe and reliable.