Real‐time probe tracking using EM‐optical sensor for MRI‐guided cryoablation

Background

A method of real‐time, accurate probe tracking at the entrance of the MRI bore is developed, which, fused with pre‐procedural MR images, will enable clinicians to perform cryoablation efficiently in a large workspace with image guidance.

Methods

Electromagnetic (EM) tracking coupled with optical tracking is used to track the probe. EM tracking is achieved with an MRI‐safe EM sensor working under the scanner's magnetic field to compensate the line‐of‐sight issue of optical tracking. Unscented Kalman filter‐based probe tracking is developed to smooth the EM sensor measurements when occlusion occurs and to improve the tracking accuracy by fusing the measurements of two sensors.

Results

Experiments with a spine phantom show that the mean targeting errors using the EM sensor alone and using the proposed method are 2.21 mm and 1.80 mm, respectively.

Conclusion

The proposed method achieves more accurate probe tracking than using an EM sensor alone at the MRI scanner entrance.     

Pelvic‐floor imaging using three‐dimensional ultrasonography and magnetic resonance imaging in the long term follow‐up of the bladder‐exstrophy‐epispadias complex

Study Type – Therapy (case control)
Level of Evidence 3b

OBJECTIVE

To investigate whether established pelvic floor variables can be used to predict the risk of uterine prolapse after surgery and to compare two different operative strategies, pelvic adaptation with functional reconstruction and an open pelvis with urinary diversion, as a congenital bony pelvis and pelvic floor defect predisposes females with bladder‐exstrophy‐epispadias complex (BEEC) to uterine prolapse.

PATIENTS, SUBJECTS AND METHODS

We conducted a cross‐sectional study using perineal three‐dimensional ultrasonography (3D‐US) and magnetic resonance imaging (MRI) to describe pelvic floor anatomy in 19 women with BEEC (mean age 27.3 years) and five controls, with the outcome evaluated by a semi‐structured interview. The analysis of 3D‐US and MRI was conducted by two independent investigators.

RESULTS

Of the 19 women with BEEC, 13 initially had a functional bladder reconstruction, six a urinary diversion with removal of the exstrophic bladder, and 12 women had closure of the pelvis either by traction bandage or osteotomy, and in the other seven the symphysis was not approximated. Four patients had a complete and one a mild uterine prolapse. After a mean follow‐up of 24 years, the mean symphyseal diastasis was 4.5 cm after symphyseal approximation, 9.0 cm without symphyseal approximation in BEEC and 0.49 cm in controls. The mean levator hiatus was 4.9 cm on 3D‐US and 4.1 cm on MRI after symphyseal approximation, 5.9 and 7.6 cm without symphyseal approximation and 4.2 and 3.2 cm in controls, respectively. The respective mean levator angle was 86.6° and 87.3° after symphyseal approximation, 104.1° and 101.3° without and 71.3° and 45.5 in controls. Prolapse was statistically significantly more common in patients with no symphyseal approximation.

CONCLUSION

This is the first study showing that perineal 3D‐US is useful for pelvic floor imaging in BEEC. Established pelvic floor variables might be useful for predicting the risk of pelvic organ prolapse in BEEC.     

Combined treatment with a β3‐adrenergic receptor agonist and a muscarinic receptor antagonist inhibits detrusor overactivity induced by cold stress in spontaneously hypertensive rats

Aims

This study determined if combined treatment with the muscarinic receptor (MR) antagonist solifenacin and the β₃‐adrenergic receptor (AR) agonist mirabegron could inhibit detrusor overactivity induced by cold stress in spontaneously hypertensive rats (SHRs).

Methods

Thirty‐two female 10‐week‐old SHRs were fed an 8% NaCl‐supplemented diet for 4 weeks. Cystometric measurements of the unanesthetized, unrestricted rats were performed at room temperature (RT, 27 ± 2°C) for 20 min. The rats were then intravenously administered vehicle, 0.1 mg/kg solifenacin alone, 0.1 mg/kg mirabegron alone, or the combination of 0.1 mg/kg mirabegron and 0.1 mg/kg solifenacin (n = 8 each group). Five minutes later, the treated rats were exposed to low temperature (LT, 4 ± 2°C) for 40 min. Finally, the rats were returned to RT. After the cystometric investigations, the β₃‐ARs and M₃‐MRs expressed within the urinary bladders were analyzed.

Results

Just after transfer from RT to LT, vehicle‐, solifenacin‐, and mirabegron‐treated SHRs exhibited detrusor overactivity that significantly decreased voiding interval and bladder capacity. However, treatment with the combination of solifenacin and mirabegron partially inhibited the cold stress‐induced detrusor overactivity patterns. The decreases of voiding interval and bladder capacity in the combination‐treated rats were significantly inhibited compared to other groups. Within the urinary bladders, there were no differences between expression levels of M₃‐MR and β₃‐AR mRNA. The tissue distribution of M₃‐MRs was similar to that of the β₃‐ARs.

Conclusions

This study suggested that the combination of solifenacin and mirabegron act synergistically to inhibit the cold stress‐induced detrusor overactivity in SHRs. Neurourol. Urodynam. 36:1026–1033, 2017. © 2016 The Authors. Neurourology and Urodynamics Published by Wiley Periodicals, Inc.     

ABO‐incompatible liver transplantation for severe hepatitis B patients

Effect of ABO‐incompatible liver transplantation on patients with severe hepatitis B (SHB) remains unclear. Herein, we summarized 22 cases with SHB in whom were performed emergency liver transplantation from ABO‐incompatible donors. The immunosuppressive protocol consisted basiliximab, tacrolimus, steroids and mycophenolate mofetil. The mean MELD score was 35.2 ± 7.1. Major complications included rejection, infections, biliary complications, hepatic artery thrombosis or stenosis and portal vein thrombosis. Patient survival rates were 40.9%, 78.9% and 82.3% in 1 year, 29.2%, 66.8% and 72.9% in 3 years, and 21.9%, 60.1% and 62.5% in 5 years for ABO‐incompatible, ABO‐compatible and ABO‐identical groups. Graft survival rates were 39%, 78.9% and 82.3% in 1 year, 27.8%, 66.4% and 71.1% in 3 years, and 20.9%, 57.9% and 61.0% in 5 years for incompatible, compatible and identical ABO graft‐recipient match. The 1‐, 3‐, 5‐year graft and patient survival rates of ABO‐incompatible were distinctly lower than that of ABO‐compatible group (P < 0.05). Our results suggested that ABO‐incompatible liver transplantation might be a life‐saving procedure for patients with SHB as a promising alternative operation when ABO‐compatible donors are not available and at least bridges the second opportunity for liver retransplantation.     

A modified side‐to‐end lymphaticovenular anastomosis

Background:

Lymphaticovenular anastomosis (LVA) is a useful treatment for compression‐refractory lymphedema with its effectiveness and minimal invasiveness. However, LVA requires supermicrosurgery, where lymphatic vessels with a diameter of 0.5 mm or smaller are anastomosed using 11‐0 or 12‐0 suture. To make LVA easier and safer, we adopted a modified side‐to‐end (S‐E) anastomosis in LVA surgery.

Methods:

We performed modified S‐E LVAs in 14 limbs of female patients with lower extremity lymphedema (LEL). In modified S‐E LVA, lateral windows with a length of 1.0 mm or longer were created on a lymphatic vessel and a vein, respectively, and side‐to‐side (S‐S) anastomosis was established with 10‐0 continuous suture. After completion of S‐S anastomosis, the vein distal to the anastomosis site was ligated to prevent venous backflow and subsequent thrombosis at the anastomosis site. Lymphedematous volume was evaluated preoperatively and at postoperative 6 months using LEL index.

Results:

All the 24 modified S‐E anastomoses could be completed without difficulty or revision for anastomosis, and showed good patency after completion of anastomosis. Postoperatively, LEL indices significantly decreased compared with preoperative LEL index (255.9 ± 14.1 vs. 274.9 ± 22.2, P < 0.001).

Conclusions:

Modified S‐E LVA can efficaciously divert lymph flows into venous circulation without performing supermicrosurgical anastomosis. © 2012 Wiley Periodicals, Inc., Microsurgery, 2013.     

Induction of porcine‐specific regulatory T cells with high specificity and expression of IL‐10 and TGF‐β1 using baboon‐derived tolerogenic dendritic cells

Background

Regulatory T cells (Treg) play an important role in maintenance of homeostasis in vivo. Treg application to alleviate allo‐organ rejection is being studied extensively. However, natural Treg (nTreg) expansion in vitro is laborious and expensive. Antigen‐specific Treg are more effective and require lower cell numbers than use of nTreg for immune control. The baboon, as a non‐human primate experimental animal model, is widely used in xenotransplantation research. An effective method to generate baboon xeno‐specific Treg would benefit research on immune tolerance in xenotransplantation using this model system.

Method

Baboon tolerogenic dendritic cells (tolDC) were generated in 3 days from monocytes isolated from baboon peripheral blood mononuclear cells in medium supplemented with anti‐inflammatory cytokines. After loading with porcine‐specific (PS) in vitro‐transcribed RNA (ivtRNA), tolDC were used to induce CD4⁺ T cells to become porcine‐specific Treg (PSTreg) in cocultures supplemented with IL‐2 and rapamycin for 10 days. Anti‐inflammatory and inflammatory cytokine expression was evaluated at the mRNA and protein levels in both baboon tolDC and PSTreg. Functional assays, suppression of activation markers on porcine‐specific effector T cells (PSTeff) and inhibition of PSTeff proliferation, were used to test PSTreg specificity.

Results

TolDC generated with this method exhibited a tolerogenic phenotype, expressed CCR7 and produced high levels of IL‐10 and TGF‐β1, whereas IL‐12p40 and IFN‐γ were not expressed. PSTreg were successfully generated in cocultures of CD4⁺ T cells and PS ivtRNA‐loaded tolDC. They exhibited a CD3⁺ CD4⁺ CD25⁺ CD127^low/? CD45RA^low Foxp3⁺ phenotype and were characterized by high expression of IL‐10 and TGF‐β1 mRNA and protein. They showed upregulated expression of EBI3 and GARP mRNA. PSTreg exhibited highly suppressive effects toward PSTeff, secreting high amounts of IL‐10 and TGF‐β1 cytokine upon interaction with PSTeff and suppressing IFN‐γ expression on PSTeff.

Conclusion

In this study, a fast 3‐day method to generate baboon‐derived tolDC is provided that allows subsequent induction of PSTreg displaying high porcine‐antigen specificity and expression of IL‐10 and TGF‐β1. Porcine‐specific baboon Treg can be used in porcine solid organ or cell xenotransplantation studies through adoptive cell transfer into host baboons.     

Performance analysis of the T‐DOC® air‐charged catheters: An alternate technology for urodynamics

Aims

Urodynamics (UDS) is widely used for the diagnosis of lower urinary tract dysfunction. Air‐Charged catheters (ACC), one of the newer technologies for UDS pressure recording, has been adopted in growing numbers around the world for the past 15 years. Currently, there is a lack of published studies characterizing specific performance of the ACC. Since linearity, hysteresis, pressure drift, and frequency response are important components in characterizing accuracy for catheter‐manometer systems; this study aimed to assess these four aspects in ACC.

Methods

A total of 180 T‐DOC® ACC were used in three different laboratory settings to assess pressure linearity and hysteresis (15 dual‐sensor vesical and urethral and 30 single‐sensor abdominal), pressure drift over 2 h (115 single‐sensor), and frequency response (20 single‐sensor). Data are presented as mean ± standard deviation.

Results

ACC showed linearity of 0.99 ± 0.01, 0.99 ± 0.01, and 1.01 ± 0.01; and hysteresis of 0.57 ± 0.3%, 0.76 ± 0.48%, and 1 ± 0.89% for the abdominal, vesical, and urethral sensors, respectively. A pressure drift of 2.2 ± 1.4% at 1 h and 4.4 ± 2.5% at 2 h were observed when compared to baseline pressures. The catheters did not show any amplification factor during the sweep from 1 to 30 Hz, and recorded signals up to 5 Hz attenuating higher frequency signals.

Conclusions

In this study the T‐DOC® ACC showed a linear performance with minimal hysteresis associated with acceptable pressure drift, and adequate frequency response to capture clinically relevant pressures. The accurate results observed in this study suggest that these catheters are technically suitable to be used as a measuring instrument for UDS.     

Development of a new 3‐DOF parallel manipulator for minimally invasive surgery

This article proposes a novel dexterous endoscopic parallel manipulator for minimally invasive surgery. The proposed manipulator has 3 degrees of freedom (3‐DOF), which consist of two rotational DOFs and one translational DOF (2R1T DOFs). The manipulator consists of 3 limbs exhibiting identical kinematic structure. Each limb contains an active prismatic joint followed by 2 consecutive passive universal joints. The proposed manipulator has a unique arrangement of its joints' axes. This unique arrangement permits large bending angles, ±90° in any direction, and a workspace almost free from interior singularities. These advantages allow the proposed manipulator to outperforms existing surgical manipulators. However, this unique arrangement makes the analysis of the robot extremely difficult. Therefore, a geometrical/analytical approach is used to facilitate its singularity analysis. Construction of the virtual prototype is accomplished using ADAMS software to validate the proposed manipulator and its bending capability. A closed‐form solution for inverse kinematics is obtained analytically. Also, the forward kinematics solution is obtained numerically. Moreover, evaluation of the workspace is achieved using motion/force transmissibility indices. A practical experiment has been performed using a scaling technique and PID controller. The experimental results show the feasibility of the teleoperated surgical system using the proposed parallel manipulator as the slave.     

Comparative Study Between M6‐C and Mobi‐C Cervical Artificial Disc Replacement: Biomechanical Outcomes and Comparison with Normative Data

Objective

Cervical spondylosis affects a huge proportion of the middle‐aged population. Degenerative changes can occur in multiple regions of the cervical spine typically affecting the joints, intervertebral discs and endplates. These changes lead to compression of adjacent nervous structures, which results in radiculopathic and myelopathic pain. Various treatment modalities are currently available with non‐surgical approaches the initial go to if there is no symptomatic cord compression. Anterior cervical discectomy and fusion, or arthroplasty are the two common surgical approaches if non‐surgical treatments fail to relieve symptoms of the patients or there are signs of central cord compression. However, studies have shown that there is an increased risk of adjacent segment disease related to fusion. Cervical disc arthroplasty aims to restore normal range of motion (ROM) in patients with pain and disability due to degenerative disc disease resistant to conservative care. Two common disc prostheses used include M6‐C and Mobi‐C. Both prostheses comprise a mobile polymer segment sandwiched between two metal endplates with mechanisms resembling an actual intervertebral disc. This study aims to compare the kinematics associated with these prostheses, against the normal range of motion in the non‐degenerative population.

Method

Patients who underwent M6‐C or Mobi‐C disc replacements by the senior author from 2012 to 2015 were identified at a single tertiary institution. Routine 3‐month postoperative lateral radiographs were analyzed for flexion and extension ROM angles at the involved vertebral level by two independent authors. Data was compared to previous published studies investigating cervical spine ROM of asymptomatic patients.

Results

There was no statistical significance in the difference of overall flexion range between M6‐C and Mobi‐C prostheses. However, overall range of extension of Mobi‐C was greater compared to M6‐C (P = 0.028). At C_5–6, the range of flexion for both implants were similar but lesser compared to asymptomatic patients (P < 0.001). Range of extension was greater in the Mobi‐C group (14.2° ± 5.1°) compared to the M6‐C (7.3° ± 4.6°) (P = 0.0009). At C_6–7, there were no statistical differences in both range of flexion and extension between the two prostheses and asymptomatic patients (P > 0.05).

Conclusion

The early results regarding restoration of ROM following cervical arthroplasty using either M6‐C or Mobi‐C prosthesis are encouraging. Long‐term follow‐up studies are necessary to observe the change in ROM over time with physiological loading and wear patterns.

     

Combined treatment for facial rejuvenation using an optimized pulsed light source followed by a fractional non‐ablative laser

Background

Combination laser treatments can potentially increase the effectiveness of treatment without the additional downtime associated with another procedure.

Objective

To assess the effectiveness and safety of combining non‐ablative fractional treatments with optimized intense pulsed light.

Methods and Materials

Ten subjects (Group A) received full face treatments with a non‐ablative fractional either followed or preceded by an optimized intense pulsed light source. Twenty‐six subjects (Group B) received only full face treatments with the same non‐ablative, fractional laser device.

Results

For Group A, the overall average Fitzpatrick Wrinkle Scale for all patients improved from 6.3 ± 1.1 at baseline to 5.9 ± 0.8 one month following one treatment for an average improvement of 0.4 ± 0.6 (P < 0.10 paired t‐test n = 9). The average pigment improvement score was 1.8 ± 0.9 on a 4‐point scale. In Group B, the average Fitzpatrick Wrinkle Scale improved from 6.0 ± 1.6 at baseline to 5.2 ± 1.4 at 3 months for an average improvement of 0.8 ± 0.7 (P < 0.001, n = 26 paired t‐test). The average pigment improvement score was 1.4 ± 1.0 (P < 0.001, t‐test, n = 26). Adverse events were similar in the two groups.

Conclusion

The combination of an optimized intense pulsed light source with a non‐ablative fractional laser during the same treatment session is safe and effective. Lasers Surg. Med. 45:405–409, 2013. © 2013 Wiley Periodicals, Inc.     

Pelvic Tilt Displacement Before and After Artificial Hip Joint Replacement Surgery

Background

Prediction of pelvic displacement before total hip arthroplasty (THA) is important for accurate acetabular implant placement. This study aimed to evaluate the effect of contralateral joint conditions on pelvic displacement after THA.

Pancreatico‐jejunostomy decreases post‐operative pancreatic fistula incidence and severity after central pancreatectomy

Backgrounds

Central pancreatectomy (CP) is an alternative to pancreaticoduodenectomy and distal pancreatectomy in benign tumours of pancreatic isthmus management. It is known for a high post‐operative pancreatic fistula (POPF) rate. The purpose of this study was to compare POPF incidence between pancreatico‐jejunostomy (PJ) and pancreatico‐gastrostomy (PG).

Methods

Fifty‐eight patients (mean age 53.9 ± 1.9 years) who underwent a CP in four French University Hospitals from 1988 to 2011 were analysed. The distal pancreatic remnant was either anastomosed to the stomach (44.8%, n = 25) or to a Roux‐en‐Y jejunal loop (55.2%, n = 35) with routine external drainage allowing a systematic search for POPF. POPF severity was classified according to the International Study Group on Pancreatic Fistula (ISGPF) and Clavien‐Dindo classifications.

Results

The groups were similar on sex ratio, mean age, ASA score, pancreas texture, operative time and operative blood loss. Mean follow‐up was 36.2 ± 3.9 months. POPF were significantly more frequent after PG (76.9 versus 37.5%, P = 0.003). PG was associated with significantly higher grade of POPF both when graded with ISGPF classification (P = 0.012) and Clavien‐Dindo classification (P = 0.044). There was no significant difference in post‐operative bleeding (0.918) and delayed gastric emptying (0.877) between the two groups. Hospital length of stay was increased after PG (23.6 ± 3.5 days versus 16.5 ± 1.9 days, P = 0.071). There was no significant difference in incidence of long‐term exocrine (3.8 versus 19.2%, P = 0.134) and endocrine (7.7 versus 9.4%, P = 0.575) pancreatic insufficiencies.

Conclusion

PG was associated with a significantly higher POPF incidence and severity in CP. We recommend performing PJ especially in older patients to improve CP outcomes.     

The effects of multiple freeze–thaw cycles on the biomechanical properties of the human bone‐patellar tendon‐bone allograft

Soft tissue allografts, such as the bone‐patellar tendon‐bone (BPTB) graft, have been frequently used for anterior cruciate ligament (ACL) reconstruction. As allografts are subjected to freezing and thawing for multiple cycles, the objective of this study was to measure the changes of the biomechanical properties of the human BPTB allograft after 4 and 8 freeze–thaw cycles in comparison to a single freeze–thaw cycle. Three BPTB specimens were procured from 21 human donors and divided into three groups: 1, 4, or 8 freeze–thaw cycles. Each freeze–thaw cycle consisted of freezing at ?20 ± 10°C for more than 6 h and thawing at 22 ± 3°C for at least 6 h. Tensile testing of the BPTB specimens consisted of loading between 50 N and 250 N for 100 cycles and then loading to failure. Cyclic loading revealed a similar amount of creep (～0.5 mm) among the three freeze–thaw cycles groups (p = 0.38). The stiffness of the BPTB graft for the 1, 4, and 8 freeze–thaw cycle groups were 244 ± 42 N/mm, 235 ± 39 N/mm, and 231 ± 40 N/mm, respectively (p = 0.43). Similar findings were obtained for the ultimate load of the BPTB graft (p = 0.14) and the tangent modulus of the PT substance (p = 0.41). The results of this study suggest that there would be little measurable effect on the structural properties of the BPTB graft or mechanical properties of the PT tissue substance following 8 freeze–thaw cycles. These BPTB allografts could potentially be re‐frozen without a loss in their biomechanical properties, given appropriate storage and care. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1193–1198, 2011     

Primary Cooperative Application of a LARS® Tube and 3D-Printed Prosthesis for Reconstruction of the Distal Radius after en bloc Resection of Giant Cell Tumor of Bone: A Comparative Retrospective Study

Objective

Using a fibula autograft (FA) to reconstruct defects after en bloc resection of giant cell tumor of bone (GCTB) in the distal radius is classic but has high complication rates. We describe a novel reconstruction method employing the cooperative application of LARS® and a 3D-printed prosthesis (L-P) and investigate whether it improves postoperative outcomes.

Methods

From April 2015 to August 2022, 14 patients who underwent the cooperative L-P reconstruction method after en bloc resection of distal radial GCTBs and 31 patients who received FA reconstruction were enrolled as two retrospective cohorts in this comparative study. The properties of the implants and critical surgical techniques were elaborated in the L-P group. Preoperative function, intraoperative data, and postoperative clinical, functional, and radiographic outcomes of all patients were recorded and compared between the two groups. The grip strength and range of wrist motion, including extension, flexion, radial deviation, and ulnar deviation, were measured. The Mayo modified wrist and Musculoskeletal Tumor Society scores were chosen to assess wrist function and surgical functional outcomes, respectively. Kaplan–Meier curves were generated to analyze the significant differences in complication rates and implant survival between the two groups.

Results

In both groups, all 45 patients underwent the operation without complication with similar average osteotomy lengths and bleeding volumes, while a shorter operative duration was achieved in the L-P group (201.43 ± 22.87 min vs. 230.16 ± 51.44 min, P = 0.015). At a mean follow-up of 40.42 ± 18.43 months (range, 14–72 months), both reconstruction methods effectively ameliorated postoperative function. Patients who received L-P showed higher postoperative modified Mayo wrist scores (81.43 ± 5.49 vs. 71.13 ± 16.10, P = 0.003), Musculoskeletal Tumor Society scores (27.64 ± 1.34 vs. 25.06 ± 2.95, P = 0.004), and grip strength on the normal side (68.71% ± 8.00% vs. 57.81% ± 12.31%, P = 0.005) than the FA group. Better wrist extension (63.21° ± 8.99° vs. 45.32° ± 14.53°, P < 0.001) and flexion (45.36° ± 7.90° vs. 30.48° ± 12.07°, P < 0.001) were also observed in the L-P group. The complication rate was significantly higher in the FA group (29/31, 93.55%) than in the L-P group (1/14 7.14%, P < 0.001). The L-P group showed higher implant survival than the FA group, but the difference was not statistically significant.

Conclusion

The cooperative application of LARS® and 3D-printed prostheses is an effective modality for reconstructing musculoskeletal defects after en bloc resection of distal radial GCTBs, which can improve functional outcomes, diminish complication rates, and promote wrist joint stability and motion.     

Ultrasound evidence of the optimal wrist position for radial artery cannulation

Purpose

Radial artery cannulation is a common medical procedure for anesthesia and critical care. To establish the ideal wrist position for radial artery cannulation, we performed ultrasound examinations of the radial artery to investigate the effect of the angle of wrist extension on radial artery dimensions.

Clinical features

Measurements were performed in 17 healthy subjects and 17 surgical patients scheduled for coronary artery bypass graft (CABG) surgery. The radial artery was echographically visualized near the styloid process of the radius at the wrist. Radial artery dimensions were measured at wrist joint angles of 0, 15, 30, 45, 60 and 75°.

Observations

In both groups, radial artery height was affected by the wrist joint angle. Vessel height was decreased at 60° (one way ANOVA P = 0.027 vs 0°) and 75° (P < 0.001 vs 0, 15, 45°) in healthy subject and at 75° in CABG patients (P < 0.001 vs 0°). The mean differences in radial artery height at 0 and 75° were 0.33 ± 0.09 mm and 0.20 ± 0.06 mm for healthy and CABG patients, respectively. Vessel width was not affected by wrist joint angulation up to 75° of extension.

Conclusion

Our results demonstrate that in healthy subjects, radial artery dimensions are unaltered when the wrist joint is extended up to an angle of 45°. Extension at 60° for healthy subjects and 75° for CABG patients, however, results in a decrease in the height of the radial artery, which could possibly render arterial catheterization more difficult.     

High neutrophil‐to‐lymphocyte ratio predicts worse overall survival in patients with advanced/metastatic urothelial bladder cancer

Objectives

To study the role of the neutrophil‐to‐lymphocyte ratio in predicting survival outcomes for patients with advanced bladder cancer.

Methods

We retrospectively reviewed 150 patients diagnosed with advanced or metastatic bladder cancer between January 2004 and June 2014. The neutrophil‐to‐lymphocyte ratio was computed on diagnosis and after the first cycle of chemotherapy. A neutrophil‐to‐lymphocyte ratio cut‐off of 3.0 was determined, with a concordance index of 0.89. Kaplan–Meier curves, log–rank tests, Cox proportional hazards and logistic regression models were used to predict the association of the neutrophil‐to‐lymphocyte ratio with survival outcomes.

Results

Just five patients were alive at the end of the study; the rest died from metastatic bladder cancer. On multivariate analysis, higher Eastern Cooperative Oncology Group status, lymphadenopathy, visceral metastases and neutrophil‐to‐lymphocyte ratio ≥3.0 were associated with poorer overall survival (hazard ratio 1.67, P = 0.03; hazard ratio 1.97, P = <0.01; hazard ratio 2.02, P = <0.01; hazard ratio 5.06, P = <0.01), whereas chemotherapy conferred better overall survival (hazard ratio 0.546, P = 0.01). Furthermore, the role of chemotherapy prolonged survival longer in patients with a neutrophil‐to‐lymphocyte ratio <3.0 (median overall survival 13.0 vs 22.0 months, hazard ratio 0.273, P = 0.008) compared with a neutrophil‐to‐lymphocyte ratio ≥3.0 (median overall survival 4.0 vs 7.0 months, hazard ratio 0.452, P = 0.020). More importantly, when dichotomized to the four different pre‐ and post‐chemotherapy groups, patients with a pre‐ and post‐chemotherapy neutrophil‐to‐lymphocyte ratio <3.0 had the best additional median overall survival of 19.0 months compared with patients with a pre‐ and post‐chemotherapy neutrophil‐to‐lymphocyte ratio ≥3.0 (3.0 months).

Conclusions

Elevated neutrophil‐to‐lymphocyte ratio is independently associated with poorer chemotherapeutic response and overall survival in patients with advanced or metastatic bladder cancer. The neutrophil‐to‐lymphocyte ratio can be an inexpensive novel factor in prognosticating disease progression and providing better patient counseling.     

Effects of the jaw‐thrust manoeuvre in the semi‐sitting position on securing a clear airway during fibreoptic intubation

Securing a clear airway is important for successful fibreoptic intubation. We investigated whether the jaw‐thrust manoeuvre in the 25° semi‐sitting position improves airway clearance compared with the supine position in 88 anaesthetised patients randomly assigned to the two positions. After induction of anaesthesia, the fibreoptic bronchoscope was advanced into the mouth along the dorsum of the tongue during the jaw‐thrust manoeuvre. Airway clearance was assessed at the level of the soft palate and epiglottis. Patients in the 25° semi‐sitting position had clearer airways (judged subjectively by a three‐level scale) than those in the supine position at the soft palate level (p = 0.012). At the level of the epiglottis, airway clearance was equally good in both positions. The mean (SD) times to view the vocal cord and carina were shorter in the 25° semi‐sitting position (4 (1) s and 8 (1) s, respectively) compared with the supine position (6 (3) s and 11 (3) s; p < 0.001, respectively). The time to achieve intubation was also shorter in the 25° semi‐sitting position (21 (5) s) than in the supine position (25 (7) s; p = 0.018).     

A randomized cross‐over comparison of short‐term exposure of once‐daily extended release tacrolimus and twice‐daily tacrolimus on renal function in healthy volunteers

Calcineurin inhibitor nephrotoxicity remains an issue for transplant recipients. The pharmacokinetic profile (PK) of the once‐daily tacrolimus extended release (Tac‐ER) includes equivalent exposure [AUC_(0–24 h)] but lower C_max versus twice‐daily tacrolimus immediate release (Tac‐IR). We hypothesized that the unique PK profiles would result in pharmacodynamic differences in renal function. Nineteen healthy male subjects were allocated to once‐daily Tac‐ER and twice‐daily Tac‐IR in a prospective, randomized, two period, cross‐over study. Tacrolimus was titrated to achieve trough levels of 8–12 ng/ml. Twenty four hours ERPF and GFR estimated by para‐aminohippurate and sinistrin clearance were performed at baseline and at the end of each 10‐day dosing period. Mean Tac C₀ was 11.0 ± 2.2 and 11.3 ± 1.8 ng/ml for Tac‐ER and Tac‐IR, respectively. The mean Effective 24 h renal plasma flow (ERPF) was significantly higher with Tac‐ER compared with Tac‐IR (658 ± 127 vs. 610 ± 93 ml/min/1.73 m², P = 0.046). There was a trend to a greater mean GFR over 24 h for Tac‐ER at 114.5 ± 13.6 ml/min/1.73 m² compared with 108.9 ± 9.7 ml/min/1.73 m² for Tac‐IR, P = 0.116. Under controlled physiological conditions, ERPF was significantly improved with Tac‐ER compared with Tac‐IR, likely owing to the differing PKs of these tacrolimus preparations (ClinicalTrials.gov Identifier: NCT01681134).     

Evaluation of MDRD4, CKD‐EPI,BIS‐1, and modified Cockcroft–Gault equations to estimate glomerular filtration rate in the elderly renal‐transplanted recipients

Equations to estimate glomerular filtration rate (eGFR) were developed in patients using the variables age, body weight, and serum creatinine, which may be different in the elderly. Elderly renal transplant patients (EG; n=70; mean age 65 ± 4 y) who measured plasma ⁵¹Cr‐EDTA‐Clearance (mGFR) had mGFR compared to eGFR obtained by the Cockcroft–Gault corrected by body surface area (CG‐BSA), the modification of diet in renal disease (MDRD‐4), the Berlin Initiative Study (BIS‐1), and the chronic kidney disease epidemiology collaboration (CKD‐EPI). Results were validated using a cohort of 43, of the 70 elderly recipients, who performed a second ⁵¹Cr‐EDTA‐Clearance. Mean mGFR was 47 ± 16 mL/min/1.73 m² and statistically lower than eGFR by MDRD (52 ± 19, P=.001) and BIS‐1 (51 ± 13, P=.007) but not different from the CG‐BSA (47 ± 15) and CKD‐EPI (49 ± 18). The CKD‐EPI and CG‐BSA presented the lowest bias but only CKD‐EPI also showed the highest 30% and 10% accuracy. The same findings were repeated in the validation set. For a cohort of elderly recipients ≥65 years (n=35, 68 ± 3y), the CKD‐EPI performed better with the lowest bias (0 ± 12 mL/min/1.73 m²) and best 30% and 10% accuracy. The CKD‐EPI equation is a valuable tool to monitor GFR in the elderly RTx recipients.     

Is Increased Acetabular Cartilage or Fossa Size Associated With Pincer Femoroacetabular Impingement?

Background

Surgical treatment for pincer femoroacetabular impingement (FAI) of the hip remains controversial, between trimming the prominent acetabular rim and reverse periacetabular osteotomy (PAO) that reorients the acetabulum. However, rim trimming may decrease articular surface size to a critical threshold where increased joint contact forces lead to joint degeneration. Therefore, knowledge of how much acetabular articular cartilage is available for resection is important when evaluating between the two surgical options. In addition, it remains unclear whether the acetabulum rim in pincer FAI is a prominent rim because of increased cartilage size or increased fossa size.

Questions/purposes

We used reformatted MR and CT data to establish linear length dimensions of the lunate cartilage and cotyloid fossa in normal, dysplastic, and deep acetabula.

Methods

We reviewed the last 200 hips undergoing PAO, reverse PAO, and surgical dislocation for acetabular rim trimming at one institution. We compared MR images of symptomatic hips with acetabular dysplasia (20 hips), pincer FAI (29 hips), and CT scans of asymptomatic hips from patients who underwent CT scans for reasons other than hip pain (20 hips). These hips were chosen sequentially from the underlying pool of 200 potential subjects to identify the first 10 male and the first 10 female hips in each group that met inclusion criteria. As a result of low numbers, we included all hips that had undergone reverse PAO and met inclusion criteria. Cartilage width was measured medially from the cotyloid fossa to the lateral labrochondral junction. Cotyloid fossa linear height was measured from superior to inferior and cotyloid fossa width was measured from anterior to posterior. Superior lunate cartilage width (SLCW) and cotyloid fossa height (CFH) were measured on MR and CT oblique coronal reformats; anterior lunate cartilage width (ALCW), posterior lunate cartilage width (PLCW), and cotyloid fossa width (CFW) were measured on MR and CT oblique axial reformats. Cohorts were compared using multivariate analysis of variance with Bonferroni’s adjustment for multiple comparisons.

Results

Compared with control acetabula, dysplastic acetabula had smaller SLCW (2.08 ± 0.29 mm versus 2.63 ± 0.42 mm, mean difference = ?0.55 mm; 95% confidence interval [CI] = ?0.83 to ?0.27; p < 0.01), ALCW (1.20 ± 0.34 mm versus 1.64 ± 0.21 mm, mean difference = ?0.44 mm; 95% CI = ?0.70 to ?0.18; p = 0.00), CFH (2.84 ± 0.37 mm versus 3.42 ± 0.57 mm, mean difference = ?0.59 mm; 95% CI = ?0.96 to ?0.21; p < 0.01), and CFW (1.98 ± 0.50 mm versus 2.77 ± 0.33 mm, mean difference = ?0.80 mm; 95% CI = ?1.16 to ?0.42; p < 0.0001). Based on the results, we identified two subtypes of deep acetabula. Compared with controls, deep subtype 1 had normal CFH and CFW but increased ALCW (2.09 ± 0.42 mm versus 1.64 ± 0.21 mm; p < 0.001) and PLCW (2.32 ± 0.36 mm versus 2.00 ± 0.32 mm; p = 0.04). Compared with controls, deep subtype 2 had increased CFH (4.37 ± 0.51 mm versus 3.42 ± 0.57 mm; p < 0.01) and CFW (2.76 ± 0.54 mm versus 2.77 ± 0.33 mm; p = 1.0) but smaller SCLW (2.12 ± 0.40 mm versus 2.63 ± 0.42 mm; p < 0.01).

Conclusions

Deep acetabula have two distinct morphologies: subtype 1 with increased anterior and posterior cartilage lengths and subtype 2 with a larger fossa in height and width and smaller superior cartilage length.

Clinical Relevance

In patients with deep subtype 1 hips that have increased anterior and posterior cartilage widths, rim trimming to create an articular surface of normal size may be reasonable. However, for patients with deep subtype 2 hips that have large fossas but do not have increased cartilage widths, we propose that a reverse PAO that reorients yet preserves the size of the articular surface may be more promising. However, these theories will need to be validated in well-controlled clinical studies.