Practical applications of three-dimensional printing for process improvement in the cytopathology laboratory.

With the increased availability of three-dimensional (3D) printers, innovative teaching and training materials have been created in medical fields. For pathology, the use of 3D printing has been largely limited to anatomic representations of disease processes or the development of supplies during the coronavirus disease 2019 pandemic. Herein, an institution's 3D printing laboratory and staff with expertise in additive manufacturing illustrate how this can address design issues in cytopathology specimen collection and processing. The authors' institutional 3D printing laboratory, along with students and trainees, used computer-aided design and 3D printers to iterate on design, create prototypes, and generate final usable materials using additive manufacturing. The program Microsoft Forms was used to solicit qualitative and quantitative feedback. The 3D-printed models were created to assist with cytopreparation, rapid on-site evaluation, and storage of materials in the preanalytical phase of processing. These parts provided better organization of materials for cytology specimen collection and staining, in addition to optimizing storage of specimens with multiple sized containers to optimize patient safety. The apparatus also allowed liquids to be stabilized in transport and removed faster at the time of rapid on-site evaluation. Rectangular boxes were also created to optimally organize all components of a specimen in cytopreparation to simplify and expedite the processes of accessioning and processing, which can minimize errors. These practical applications of 3D printing in the cytopathology laboratory demonstrate the utility of the design and printing process on improving aspects of the workflow in cytopathology laboratories to maximize efficiency, organization, and patient safety.

Patient Perspectives on Artificial Intelligence in Healthcare Decision Making: A Multi-Center Comparative Study.

Objective: Investigate the patient opinion on the use of Artificial Intelligence (AI) in Orthopaedics. Methods: 397 orthopaedic patients from a large urban academic center and a rural health system completed a 37-component survey querying patient demographics and perspectives on clinical scenarios involving AI. An average comfort score was calculated from thirteen Likert-scale questions (1, not comfortable; 10, very comfortable). Secondary outcomes requested a binary opinion on whether it is acceptable for patient healthcare data to be used to create AI (yes/no) and the impact of AI on: orthopaedic care (positive/negative); healthcare cost (increase/decrease); and their decision to refuse healthcare if cost increased (yes/no). Bivariate and multivariable analyses were employed to identify characteristics that impacted patient perspectives. Results: The average comfort score across the population was 6.4, with significant bivariate differences between age (p = 0.0086), gender (p = 0.0001), education (p = 0.0029), experience with AI/ML (p < 0.0001), survey format (p < 0.0001), and four binary outcomes (p < 0.05). When controlling for age and education, multivariable regression identified significant relationships between comfort score and experience with AI/ML (p = 0.0018) and each of the four binary outcomes (p < 0.05). In the final multivariable model gender, survey format, perceived impact of AI on orthopaedic care, and the decision to refuse care if it were to increase cost remained significantly associated with the average AI comfort score (p < 0.05). Additionally, patients were not comfortable undergoing surgery entirely by a robot with distant physician supervision compared to close supervision. Conclusion: The orthopaedic patient appears comfortable with AI joining the care team.

The State of Machine Learning in Spine Surgery: A Systematic Review.

STUDY DESIGN: This was a systematic review of existing literature. OBJECTIVE: The objective of this study was to evaluate the current state-of-the-art trends and utilization of machine learning in the field of spine surgery. SUMMARY OF BACKGROUND DATA: The past decade has seen a rise in the clinical use of machine learning in many fields including diagnostic radiology and oncology. While studies have been performed that specifically pertain to spinal surgery, there have been relatively few aggregate reviews of the existing scientific literature as applied to clinical spine surgery. METHODS: This study utilized Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to review the scientific literature from 2009 to 2019 with syntax specific for machine learning and spine surgery applications. Specific data was extracted from the available literature including algorithm application, algorithms tested, database type and size, algorithm training method, and outcome of interest. RESULTS: A total of 44 studies met inclusion criteria, of which the majority were level III evidence. Studies were grouped into 4 general types: diagnostic tools, clinical outcome prediction, surgical assessment tools, and decision support tools. Across studies, a wide swath of algorithms were used, which were trained across multiple disparate databases. There were no studies identified that assessed the ethical implementation or patient perceptions of machine learning in clinical care. CONCLUSIONS: The results reveal the broad range of clinical applications and methods used to create machine learning algorithms for use in the field of spine surgery. Notable disparities exist in algorithm choice, database characteristics, and training methods. Ongoing research is needed to make machine learning operational on a large scale.

Feasibility of blood testing combined with PET-CT to screen for cancer and guide intervention.

Cancer treatments are often more successful when the disease is detected early. We evaluated the feasibility and safety of multicancer blood testing coupled with positron emission tomography-computed tomography (PET-CT) imaging to detect cancer in a prospective, interventional study of 10,006 women not previously known to have cancer. Positive blood tests were independently confirmed by a diagnostic PET-CT, which also localized the cancer. Twenty-six cancers were detected by blood testing. Of these, 15 underwent PET-CT imaging and nine (60%) were surgically excised. Twenty-four additional cancers were detected by standard-of-care screening and 46 by neither approach. One percent of participants underwent PET-CT imaging based on false-positive blood tests, and 0.22% underwent a futile invasive diagnostic procedure. These data demonstrate that multicancer blood testing combined with PET-CT can be safely incorporated into routine clinical care, in some cases leading to surgery with intent to cure.

Bariatric Left Gastric Artery Embolization for the Treatment of Obesity: A Review of Gut Hormone Involvement in Energy Homeostasis.

OBJECTIVE: The global population is becoming more overweight and obese, leading to increases in associated morbidity and mortality rates. Advances in catheter-directed embolotherapy offer the potential for the interventional radiologist to make a contribution to weight loss. Left gastric artery embolization reduces the supply of blood to the gastric fundus and decreases serum levels of ghrelin. Early evidence suggests that this alteration in gut hormone balance leads to changes in energy homeostasis and weight reduction. The pathophysiologic findings and current evidence associated with the use of left gastric artery embolization are reviewed. CONCLUSION: The prevalence of obesity continues to increase at an alarming rate, and, thus far, advances in medical management have been relatively ineffective in slowing this trend. Lifestyle modifications such as diet and exercise are effective initially, but most patients regain the weight in the long term. Bariatric surgery is the most effective strategy for achieving long-term weight loss; however, as with all surgical procedures, it has potential complications.

Contemporary comparison of surgical and interventional arteriography management of blunt renal injury.

PURPOSE: High-grade renal injuries have traditionally been treated operatively. Alternatively, embolotherapy is used to control hemorrhage, but there are few studies that validate this practice after renal injury. Embolotherapy may offer an effective and safe means to arrest hemorrhage after high-grade blunt renal injury. MATERIALS AND METHODS: Retrospective analysis was performed of high-grade renal injury (grade III or higher). Patients who were initially treated with arteriography were compared with those who underwent surgery. Statistical analysis was performed with Wilcoxon rank-sum and χ(2) tests. RESULTS: Sixty-nine patients were identified, 28 of whom had contrast agent extravasation on computed tomography (CT). Of these 69 patients, 17 underwent operation and 20 underwent arteriography. The surgical cohort had a higher injury severity score (39.6 vs 24.2; P < .01), but there was no difference in renal injury grade (P = .9). The arteriography cohort received significantly more contrast medium (P < .001). Contrast agent extravasation was confirmed angiographically in six of 12 patients who had this finding on CT, and embolotherapy controlled bleeding in all six. No significant difference was noted in transfusion need, recurrent hemorrhage, creatinine level at discharge, glomerular filtration rate, or length of stay (P > .4 for each endpoint). There was a trend toward a longer stay in the intensive care unit in the surgical cohort and a higher likelihood of discharge to home in the arteriography group (P = .08 for each endpoint). CONCLUSIONS: Embolotherapy offers a safe means to diagnose and arrest hemorrhage after renal injury. The additional contrast agent needed for imaging does not increase the incidence of nephropathy irrespective of renal injury grade.

Drainage of collections associated with hernia mesh: is it worthwhile?

PURPOSE: Synthetic mesh has revolutionized abdominal wall hernia repair. However, mesh infections present a clinical problem because the standard practice of surgical excision is fraught with increased morbidity. Here, single-institutional outcomes in managing mesh-related collections via percutaneous drainage are retrospectively reviewed to assess its effectiveness. MATERIALS AND METHODS: A total of 21 patients underwent drainage of perimesh collections. Three types of mesh were employed: polytetrafluoroethylene (PTFE; n = 5), polypropylene (n = 14), and porcine dermal collagen (n = 3). One patient received both polypropylene and PTFE. Drainage was performed with ultrasound guidance (n = 19) or surgical drain exchange (n = 2). Mesh type, culture results, fluid collection size, and location were analyzed with respect to need for mesh excision. RESULTS: Sixteen of 21 patients (76%) were successfully treated with drainage. One required additional surgical capsulectomy; the mesh was salvaged. Four required mesh excision because of recurrent infection (n = 2) or lack of improvement of clinical course (n = 2). Recurrent infection occurred in six patients, with mesh salvage via conservative management or new drainage in four. Fluid cultures were positive in 68% of patients (n = 13), with Staphylococcus aureus the most common organism. Cultures did not predict mesh excision (P = .26). The PTFE excision rate trended higher compared with polypropylene (40% vs 14%; P = .27). No porcine dermal collagen mesh was excised. Neither fluid collection size nor location predicted mesh excision. Mean follow-up was 319 days (range, 6-1,406 d). CONCLUSIONS: Percutaneous drainage of suspected mesh-related abscess is effective. The use of PTFE mesh trended toward a higher excision rate.

Preoperative mapping venography in patients who require hemodialysis access: imaging findings and contribution to management.

PURPOSE: To analyze the use of preoperative venographic mapping in patients who require permanent hemodialysis access. MATERIALS AND METHODS: Ninety-one patients underwent 108 preoperative studies. Sixty-eight (75%) were documented to have ongoing or previous hemodialysis at the time of the study. A total of 154 arms were assessed with venograms (75 right, 79 left); 74 of the patients (81%) had previous access. Venographic mapping was not performed in patients with clearly usable veins as determined by the referring surgeon. RESULTS: A total of 170 veins were suitable for access creation (ie, continuous vein of suitable caliber). Of these, 78 were used (40 fistulas [51%] and 38 grafts [49%]), and 87% of accesses were successfully used for dialysis (73% primarily, 14% after additional intervention). Anatomic variants included early brachial-basilic confluence (44%), double terminal cephalic arch (4%), and brachial-basilic "ladders" (7%). Significant central venous stenosis was found in 10% of studies, limiting the ability to use the affected side for access. There were significant associations between (i) the number of previous accesses and access type created (P = .002, Fisher exact test) and (ii) the number of veins visualized and access type created (P < .001, Fisher exact test). A greater number of previous access attempts correlated with graft rather than fistula placement for permanent access, and increased numbers of veins seen on venography correlated with an increased chance of permanent access placement. CONCLUSIONS: Venography may identify clinically occult veins usable for hemodialysis access. Anatomic variants are common and may affect choice of access site.

Radiofrequency ablation of small renal cell carcinomas using multitined expandable electrodes: preliminary experience.

PURPOSE: Radiofrequency ablation is a minimally invasive, nephron-sparing option for renal cell carcinoma (RCC) in poor surgical candidates. We report our contemporary experience with RCC radiofrequency ablation using multitined expandable electrodes along with an aggressive treatment strategy to displace adjacent viscera away from probe tines. Involution of the treatment zone was assessed over time. MATERIALS AND METHODS: Over a 36-month period, a quality-assurance database identified 22 patients with 26 sporadic RCC who underwent 43 ablations during 27 radiofrequency ablation sessions. The mean age of the cohort was 71 years (range, 47-89 y). Mean RCC diameter was 2.2 cm (range, 1-4 cm). Twenty-six of radiofrequency ablation sessions were performed using multitined expandable electrodes. All ablations used CT guidance with moderate sedation. Adjunctive techniques used during ablation were recorded, as were instances in which ablation mandated penetration of tines beyond the kidney margin. Post-treatment ablation zones were measured from CT/MR images to evaluate serial involution and treatment response. RESULTS: Technical success in targeting and ablation was 100%. Follow-up periods ranged from 1 to 31 months (mean, 11.2). During this period, one patient presented with marginal local recurrence and underwent repeat radiofrequency ablation. Adjunctive techniques in four patients included water injection for displacement of the tail of the pancreas (n = 1) or descending colon (n = 3). Deliberate penetration of tines beyond the margins of the kidney was performed in 41% of cases; no hemorrhage occurred in these cases. No major complications occurred. Minor complications occurred in 17% of patients, including asymptomatic pneumothorax, perirenal hematomas, subcutaneous hematoma, and subcutaneous abscess. After 6 months, mean involution of the ablation zone was 15% from baseline volume per year. CONCLUSION: Multitined expandable radiofrequency electrodes produce a high rate of local control for small RCCs with a low complication rate, even when tine penetration of the kidney is required for an adequate tumor treatment margin. Adjacent organs can be protected with adjunctive percutaneous maneuvers.

Portal flow and arterioportal shunting after transjugular intrahepatic portosystemic shunt creation.

PURPOSE: It was postulated that a transjugular intrahepatic portosystemic shunt (TIPS) produces arterioportal shunting and accounts for reversed flow in the intrahepatic portal veins (PVs) after creation of the TIPS. This study sought to quantify this shunting in patients undergoing TIPS creation and/or revision with use of a direct catheter-based technique and by measuring changes in blood oxygenation within the TIPS and the PV. MATERIALS AND METHODS: This prospective study consisted of 26 patients. Median Model for End-stage Liver Disease and Child-Pugh scores were 13 and 9, respectively. Primary TIPS creation was attempted in 21 patients and revision of failing TIPS was undertaken in five. In two patients, TIPS creation was unsuccessful. All TIPS creation procedures but one were performed with use of polytetrafluoroethylene-covered stent-grafts. Flow within the main PV (Q(portal)) was measured with use of a retrograde thermodilutional catheter before and after TIPS creation/revision, and TIPS flow (Q(TIPS)) was measured at procedure completion. The amount of arterioportal shunting was assumed to be the increase between final Q(portal) and Q(TIPS), assuming Q(TIPS) was equivalent to the final Q(portal) plus the reversed flow in the right and left PVs. Oxygen saturation within the TIPS and the PV was determined from samples obtained during TIPS creation and revision. RESULTS: Mean Q(portal) before TIPS creation was 691 mL/min; mean Q(portal) after TIPS creation was 1,136 mL/min, representing a 64% increase (P = .049). Mean Q(TIPS) was 1,631 mL/min, a 44% increase from final Q(portal) (P = .0009). Among cases of revision, baseline Q(portal) was 1,010 mL/min and mean Q(portal) after TIPS revision was 1,415 mL/min, a 40% increase. Mean Q(TIPS) was 1,693 mL/min, a 20% increase from final Q(portal) (P = .42). Arterioportal shunting rates were 494 mL/min after TIPS creation and 277 mL/min after TIPS revision, representing 30% of total Q(TIPS) after TIPS creation and 16% of Q(TIPS) after TIPS revision. No increase in oxygen tension or saturation was seen in the PV or TIPS compared with initial PV levels. Q(TIPS) did not correlate with the portosystemic gradient. CONCLUSION: TIPS creation results in significant arterioportal shunting, with less arterioportal shunting seen among patients who undergo TIPS revision. Further work is necessary to correlate Q(TIPS) with the risk of hepatic encephalopathy and liver failure.

Experience with the recovery filter as a retrievable inferior vena cava filter.

PURPOSE: This study evaluates clinical experience with the Recovery filter as a retrievable inferior vena cava (IVC) filter. MATERIALS AND METHODS: One hundred seven Recovery filters were placed in 106 patients with an initial clinical indication for temporary caval filtration. Patients were followed up to assess filter efficacy, complications, eventual need for filter removal, time to retrieval, and ability to remove the filter. RESULTS: The patient cohort consisted of 62 men and 44 women with a mean age of 48 years (range, 18-90 y). Mean implantation time was 165 days. Indications for filter placement in patients with deep vein thrombosis (DVT) and/or pulmonary embolism (PE) included contraindication to anticoagulation (n = 33), complications of anticoagulation (n = 8), poor cardiopulmonary reserve (n = 6), large clot burden (n = 3), and PE while receiving anticoagulation (n = 1). Indications for filter placement in patients without proven PE or DVT included immobility after trauma (n = 35); recent intracranial hemorrhage, neurosurgery, or brain tumor (n = 18); and other surgical or invasive procedure (n = 3). Three patients (2.8%) had symptomatic PE after placement of the Recovery filter. No caval thromboses were detected. No symptomatic filter migrations occurred. Recovery filter removal was attempted in 15 of 106 patients (14%) at a mean of 150 days after placement. The Recovery filter was successfully retrieved in 14 of 15 patients (93%); one removal was unsuccessful at 210 days after placement. Ninety-two filters (87%) currently remain in place. CONCLUSIONS: Although all the filters were placed with the intention of being removed, a large percentage of filters were not retrieved. The Recovery filter was safe and effective in preventing PE when used as a retrievable IVC filter.

Do simultaneous bilateral tunneled infusion catheters in patients undergoing bone marrow transplantation increase catheter-related complications?

PURPOSE: Secure venous access with multiple lumens is necessary for the care of allogeneic hematopoietic stem cell transplant (HSCT) recipients. The outcomes associated with simultaneous bilateral tunneled internal jugular infusion catheter placement in the HSCT recipient population were investigated in an attempt to determine whether simultaneous introduction of these catheters compounds or magnifies the risks (infection, venous thrombosis) associated with tunneled catheters. MATERIALS AND METHODS: Patients undergoing HSCT and receiving bilateral tunneled infusion catheters in a single procedure were identified using a quality assurance data base. Medical records for the duration of catheterization were reviewed; 43 patients were included in the study (mean age, 42 years; range, 22-56). Diagnoses included acute lymphocytic leukemia (n = 4), acute myelogenous leukemia (n = 8), aplastic anemia (n = 2), chronic myelogenous leukemia (n = 17), chronic lymphocytic leukemia (n = 1), Hodgkin lymphoma (n = 1), myelodysplasia (n = 4), myelofibrosis (n = 2), and non-Hodgkin lymphoma (n = 4). Cox proportional hazards regression analysis was performed to determine differences in infection rates between dual- and triple-lumen catheters. RESULTS: Forty-three pairs of catheters were placed. All met venous access needs for HSCT recipient care. Complete follow-up was achieved for 77 of 87 (89%) catheters. The overall infection rate was 0.25 per 100 catheter-days. The rate was 0.19 and 0.33 for dual- and triple-lumen catheters, respectively (P =.15). Mechanical failure did not differ between catheter types (dual: 0.14 episodes per 100 days, triple: 0.05 per 100 days, P =.2). CONCLUSIONS: Bilateral multilumen tunneled infusion catheter placement in a single procedure using imaging guidance is safe with acceptable outcomes and meets venous access needs for HSCT. There is a trend toward higher infection rates, with more lumens and more mechanical failure with dual-lumen catheters.