Personalized 3D printed model of kidney and tumor anatomy: a useful tool for patient education

Purpose

To assess the impact of 3D printed models of renal tumor on patient’s understanding of their conditions. Patient understanding of their medical condition and treatment satisfaction has gained increasing attention in medicine. Novel technologies such as additive manufacturing [also termed three-dimensional (3D) printing] may play a role in patient education.

Methods

A prospective pilot study was conducted, and seven patients with a primary diagnosis of kidney tumor who were being considered for partial nephrectomy were included after informed consent. All patients underwent four-phase multi-detector computerized tomography (MDCT) scanning from which renal volume data were extracted to create life-size patient-specific 3D printed models. Patient knowledge and understanding were evaluated before and after 3D model presentation. Patients’ satisfaction with their specific 3D printed model was also assessed through a visual scale.

Results

After viewing their personal 3D kidney model, patients demonstrated an improvement in understanding of basic kidney physiology by 16.7 % (p = 0.018), kidney anatomy by 50 % (p = 0.026), tumor characteristics by 39.3 % (p = 0.068) and the planned surgical procedure by 44.6 % (p = 0.026).

Conclusion

Presented herein is the initial clinical experience with 3D printing to facilitate patient’s pre-surgical understanding of their kidney tumor and surgery.

     

Temporary placement of covered self-expandable metal stents in benign biliary strictures: a new paradigm? (with video)

BACKGROUND: Benign biliary strictures (BBS) are usually managed with plastic stents, whereas placement of uncovered metallic stents has been associated with failure related to mucosal hyperplasia. OBJECTIVE: We analyzed the efficacy and safety of temporary placement of a covered self-expanding metal stent (CSEMS) in BBS. DESIGN: Patients with BBS received temporary placement of CSEMSs until adequate drainage was achieved; confirmed by resolution of symptoms, normalization of liver function tests, and imaging. SETTING: Tertiary-care center with long-standing experience with CSEMSs. PATIENTS: Seventy-nine patients with BBS secondary to chronic pancreatitis (32), calculi (24), liver transplant (16), postoperative biliary repair (3), autoimmune pancreatitis (3), and primary sclerosing cholangitis (1). INTERVENTION: ERCP with temporary CSEMS placement. Removal of CSEMSs was performed with a snare or a rat-tooth forceps. MAIN OUTCOME MEASUREMENTS: End points were efficacy, morbidity, and clinical response. RESULTS: CSEMSs were removed from 65 patients. Resolution of the BBS was confirmed in 59 of 65 patients (90%) after a median follow-up of 12 months after removal (range 3-26 months). If patients who were lost to follow-up, developed cancer, or expired were considered failures, then an intent-to-treat global success rate of 59 of 79 (75%) was obtained. Complications associated with placement included 3 post-ERCP pancreatitis (4%), 1 postsphincterotomy bleed (1%), and 2 pain that required CSEMS removal (2%). In 11 patients (14%), the CSEMS migrated. In 1 patient, CSEMS removal was complicated by a bile leak that was successfully managed with plastic stents. LIMITATION: Pilot study from a single center. CONCLUSIONS: Temporary CSEMS placement in patients with BBS offers a potential alternative to surgery.     

Therapeutic potential of anti-CD137 (4-1BB) monoclonal antibodies

Introduction: 4-1BB (CD137) is an important T-cell stimulating molecule. The 4-1BB mAb or its variants have shown remarkable therapeutic activity against autoimmunity, viral infections, and cancer. Antibodies to 4-1BB have recently entered clinical trials for the treatment of cancer with favorable toxicity profile. In this article, we present a review documenting the efficacy and pitfalls of 4-1BB therapy.

Areas covered: An extensive literature search has been made on 4-1BB, spanning two decades, and a comprehensive report is presented here highlighting the origins, biological effects, therapeutic potential, and mechanistic basis of targeting 4-1BB as well as the side effects associated with such therapy.

Expert opinion: Research so far indicates that 4-1BB is highly protective against various pathological conditions including cancer. However, a few important side effects of 4-1BB therapy such as liver toxicity, thrombocytopenia, anemia, and suppressive effects on certain immune competent cells should be taken into consideration before it is used for human therapy.     

Safety of kidney biopsy in elderly: a prospective study

Kidney biopsy plays an important role in the diagnosis and management of several renal diseases. There is a general reluctance to perform kidney biopsy in elderly due to fear of complications. There is no prospective head to head trial comparing complications of percutaneous kidney biopsy in elderly versus young. This prospective study was undertaken to know the frequency and type of biopsy related complications in elderly. Biopsy was performed using a spring loaded automatic 16 G biopsy gun. Post-biopsy, patients were confined to bed rest for 24 h. A record of intraprocedural problems and post-procedural complications was kept. A total of 210 native kidney biopsies were done of which 26 were performed in elderly patients (61–78 years). Co-morbid conditions were present in 17 patients, some having more than one, hypertension (11), diabetes mellitus (5), chronic obstructive airway disease (6), interstitial lung disease (2) and coronary artery disease (2). Mean serum creatinine was 5.6 mg/dl (range 0.8–14.1 mg/dl). Pre-biopsy dialysis was given to 10 patients. Adequate tissue for histopathological diagnosis was seen in 24 out of 26 biopsies. In two elderly patients biopsy had to be abandoned though indicated due to inability to hold the breath because of underlying lung and cardiac disease. Clinico-pathologic discorrelation was seen in eight patients. Incidence of gross hematuria was more in elderly than in young (4/26 vs. 7/184 P < 0.01). Hematuria subsided within 1–2 days in three, one had persistent hematuria for 1 week. Other complications viz. gross hematuria with need of blood transfusions or hemodynamic compromise (0/26 vs. 4/184), perinephric hematoma (0/26 vs. 1/184) and need of intervention (0/26 vs. 1/184) were not higher in the elderly. We conclude that the standard precautions kidney biopsy in elderly is a safe procedure.     

Cost-consequence analysis evaluating the use of botulinum neurotoxin-A in patients with detrusor overactivity based on clinical outcomes observed at a single UK centre

OBJECTIVE(S): This study aimed to assess the resource utilisation, health benefits and cost-effectiveness of intra-detrusor injections of botulinum neurotoxin-A (BoNT/A) in patients with overactive bladder (OAB). METHODS: 101 patients with urodynamically-proven detrusor overactivity of either neurogenic (NDO; n = 63) or idiopathic (IDO; n = 38) origin received intra-detrusor injections of 200-300 units of BoNT/A in 20-30 ml saline as part of a research protocol. Twenty-nine patients received repeat injections after 7-26 months. Symptom severity and urodynamic parameters were assessed at 0, 4 and 16 weeks. The cost of therapy was quantified based on the NHS resources used by typical patients and was used to calculate the cost-effectiveness of BoNT/A compared with standard care from the perspective of the UK NHS. RESULTS: In an intent-to-treat analysis, 82% of patients showed a 25% or greater improvement in at least two out of five parameters (urinary frequency, urgency, urgency incontinence episodes, maximum cystometric capacity and maximum detrusor pressure) four weeks after treatment, reducing to 65% after 16 weeks. A 50% or greater improvement in the frequency of micturition, urgency or urgency incontinence was seen in 73% of patients at four weeks and 54% at 16 weeks. There were no significant differences between IDO and NDO patients in the proportion meeting these endpoints. Therapy cost pounds 826 per patient, with a cost-effectiveness ratio of pounds 617 per patient-year with > or = 25% clinical improvement. CONCLUSION(S): This study demonstrates that intra-detrusor BoNT/A is an effective treatment for OAB that is highly likely to be cost-effective in both idiopathic and neurogenic disease.     

Sensitized attentional performance and Fos-immunoreactive cholinergic neurons in the basal forebrain of amphetamine-pretreated rats.

BACKGROUND: The consequences of repeated exposure to psychostimulants have been hypothesized to model aspects of schizophrenia. This experiment assessed the consequences of the administration of an escalating dosing regimen of amphetamine (AMPH) on attentional performance. Fos-like immunoreactivity (Fos-IR) in selected regions of these rats' brains was examined to test the hypothesis that AMPH-sensitized attentional impairments are associated with increased recruitment of basal forebrain cholinergic neurons. METHODS: Rats were trained in a sustained attention task and then treated with saline or in accordance with an escalating dosing regimen of AMPH (1-10 mg/kg). Performance was assessed during the pretreatment and withdrawal periods and following the subsequent administration of AMPH "challenges" (.5, 1.0 mg/kg). Brain sections were double-immunostained to visualize Fos-IR and cholinergic neurons. RESULTS: Compared with the acute effects of AMPH, AMPH "challenges," administered over 2 months after the pretreatment was initiated, resulted in significant impairments in attentional performance. In AMPH-pretreated and -challenged animals, an increased number of Fos-IR neurons was observed in the basal forebrain. The majority of these neurons were cholinergic. CONCLUSIONS: The evidence supports the hypothesis that abnormally regulated cortical cholinergic inputs represent an integral component of neuronal models of the attentional dysfunctions of schizophrenia.     

A comparison between the response of patients with idiopathic detrusor overactivity and neurogenic detrusor overactivity to the first intradetrusor injection of botulinum-A toxin

PURPOSE: Several studies have shown that intradetrusor injections of botulinum neurotoxin type A (BoNT/A) may effectively treat intractable spinal neurogenic detrusor overactivity (NDO), but fewer reports exist on the use of BoNT/A in patients with idiopathic detrusor overactivity (IDO). The purpose of this study was to investigate whether comparable efficacy could be displayed in the response of patients with IDO to those with NDO. MATERIALS AND METHODS: In a prospective, open label study, patients with urgency, and/or urgency incontinence due to urodynamically proven intractable detrusor overactivity received 300 units (NDO) or 200 units (IDO) of Botox injected into the bladder with a minimally invasive outpatient technique. Urodynamic maximum cystometric capacity and maximum detrusor pressure during filling, frequency of voids (frequency), number of incontinence episodes (leak) and number of voids associated with urgency per 24 hours (urgency) from 4-day voiding diaries were compared between the 2 groups at baseline and for changes at 4 and 16 weeks after treatment. RESULTS: A total of 44 patients with spinal NDO and 31 with IDO were treated. At 16 weeks, mean +/- standard error maximum cystometric capacity increased from 229.1 +/- 24.8 to 427.0 +/- 26.9 ml, p <0.0001 in NDO and from 193.6 +/- 24.0 to 327.1 +/- 36.1 ml, p=0.0008 in IDO. Maximum detrusor pressure during filling decreased from 60.7 +/- 6.8 to 26.1 +/- 3.7 cm H2O, p <0.0001 in NDO and from 62.1 +/- 10.8 to 45.1 +/- 8.1 cm H2O, p=0.027 in IDO. Frequency decreased from 12.3 +/- 0.7 to 6.6 +/- 0.6 voids per 24 hours, p <0.0001 in NDO and from 13.6 +/- 1.1 to 8.3 +/- 0.7, p=0.0002 in IDO. Leak decreased from 3.9 +/- 0.5 to 0.7 +/- 0.2 incontinence episodes per 24 hours, p <0.0001 in NDO and from 3.2 +/- 0.8 to 0.6 +/- 0.3, p=0.0017 in IDO, and urgency decreased from 7.5 +/- 0.6 to 1.44 +/- 0.3 episodes per 24 hours, p <0.0001 in NDO and from 10.9 +/- 1.7 to 4.9 +/- 1.1, p <0.0001 in IDO. The 2 groups were comparable for baseline data, but percent improvement in urgency was greater in patients with NDO at 4 weeks (78.2% vs 56.3%, p=0.019) and 16 weeks (78.3% vs 50.7%, p=0.013). Of patients with NDO 69% required self-catheterization de novo posttreatment compared with 19.3% of those with IDO. CONCLUSIONS: Patients with intractable IDO respond to intradetrusor BoNT/A with equally significant improvements in urodynamic and lower urinary tract symptom parameters as those with spinal NDO, despite the lower dose of toxin used.     

Gait improvement surgery in diplegic children: how long do the improvements last?

Gait improvement surgery in ambulatory children with cerebral palsy performed as single-event multilevel surgery is today a well-established modality of treatment, but follow-up studies are lacking. Preoperative and follow-up gait analysis data of 32 diplegic children who underwent single-event multilevel surgery for gait improvement between 1995 and 1998 were evaluated retrospectively. Relevant sagittal plane kinematic parameters of the hip, knee, and ankle joint and time-distance parameters were considered for outcome measures in this study. Postoperative gait analysis was performed three times in all the cases: after discontinuation of the dynamic AFOs (mean 1.0 +/- 0.3 years), after discontinuation of the night splints (mean 2.3 +/- 0.7 years), and at least 1.5 years after discontinuation of physiotherapy and splints (mean 4.4 +/- 1.1 years). The aim of the study was to ascertain whether the improvements in gait function were maintained over these examinations. The authors found that gait function continued to change over 1, 2, and 3 years of follow-up. A general decrease in gait function was measurable in this collective between the first postoperative and the second postoperative evaluations. The results indicate that evaluation of gait improvement surgery in cerebral palsy performed at a minimum of 3 years after surgery would give the most predictive outcome of treatment.