Accuracy of intraoperative approximation of pelvic tilt using preoperative standing radiographs

Background

Anterior approach surgeons who utilize intraoperative fluoroscopy often try to match a preoperative radiograph as a reference for intraoperative cup position. Every degree of inaccuracy in tilt leads to a roughly 0.7° change in anteversion. This study aimed to determine how closely pelvic tilt (PT) is approximated intraoperatively when compared to preoperative anteroposterior (AP) radiographs.

Methods

This was a retrospective review of 193 primary THA's done by 2 surgeons at an academic tertiary referral center between September 2021-January 2023. There were 24 patients excluded for distorted anatomy, post-traumatic arthritis, insufficient x-rays, or a sacroiliac joint that could not be visualized on film. Data collected included age and BMI. PT was calculated using the formula, Tilt = -(ln((B/A) x (1/0.483)))/0.051. Value A is the distance from the base of the SI joint to the superior margin of the obturator foramen; value B is the height of the obturator foramen.

Results

Mean preoperative PT was 0.2° versus intraoperative PT was 3.4° (p < 0.001). Mean absolute difference was 6.5°. 48% of patients (n = 81) had an absolute difference less than 5°, 31% (n = 52) between 5° and 10°, 14% (n = 24) between 10° and 15°, and 7% (n = 12) greater than 15°. There was no correlation between BMI or age and PT discrepancy.

Conclusion

Of the patients, 21% had a discrepancy of 10° or greater between their preoperative radiographs and intraoperative fluoroscopic images. Surgeons should be aware of potential errors in cup positioning and be particularly diligent in high-risk cases.

Development of a Probabilistic Boolean network (PBN) to model intraoperative blood pressure management

BACKGROUND

Blood pressure is a vital sign for organ perfusion that anesthesiologists measure and modulate during surgery. However, current decision-making processes rely heavily on clinicians' experience, which can lead to variability in treatment across surgeries. With the advent of machine learning, we can now create models to predict the outcomes of interventions and guide perioperative decision-making. The first step in this process involves translating the clinical decision-making process into a framework understood by an algorithm. Probabilistic Boolean networks (PBNs) provide an information-rich approach to this problem. A PBN trends toward a steady state, and its decisions are easily understood via its Boolean predictor functions. We hypothesize that a PBN can be developed that corrects hemodynamic instability in patients by selecting clinical interventions to maintain blood pressure within a given range.

METHODS

Data on patients over the age of 65 undergoing surgery with general anesthesia from 2018 to 2020 were drawn from the UF Health PRECEDE data set with IRB approval (IRB201700747). Parameters examined included heart rate, blood pressure, and frequency of medications given 15 min after anesthetic induction and 15 min before awakening. The medication frequency data were truncated into a 66/33 split for the training and validation set used in the PBN. The model was coded using Python 3 and evaluated by comparing the frequency of medications chosen by the program to the values in the testing set via linear regression analysis.

RESULTS

The network developed successfully models a hemodynamically unstable patient and corrects the imbalance by administering medications. This is evidenced by the model achieving a stable, steady state matrix in all iterations. However, the model's ability to emulate clinical drug selection was variable. It was successful with its use of vasodilator selection but struggled with the appropriate selection of vasopressors.

CONCLUSIONS

The PBN has demonstrated the ability to choose appropriate interventions based on a patient's current vitals. Additional work must be done to have the network emulate the frequency at which drugs are selected from in clinical practice. In its current state, the model provides an understanding of how a PBN behaves in the context of correcting hemodynamic instability and can aid in developing more robust models in the future.

Oxygenation during general anesthesia in pediatric patients: A retrospective observational study

STUDY OBJECTIVE

Protocols are used in intensive care and emergency settings to limit the use of oxygen. However, in pediatric anesthesiology, such protocols do not exist. This study aimed to investigate the administration of oxygen during pediatric general anesthesia and related these values to PaO2, SpO2 and SaO2.

DESIGN

Retrospective observational study.

SETTING

Tertiary pediatric academic hospital, from June 2017 to August 2020.

PATIENTS

Patients aged 0-18 years who underwent general anesthesia for a diagnostic or surgical procedure with tracheal intubation and an arterial catheter for regular blood withdrawal were included. Patients on cardiopulmonary bypass or those with missing data were excluded. Electronic charts were reviewed for patient characteristics, type of surgery, arterial blood gas analyses, and oxygenation management.

INTERVENTIONS

No interventions were done.

MEASUREMENTS

Primary outcome defined as FiO2, PaO2 and SpO2 values were interpreted using descriptive analyses, and the correlation between PaO2 and FiO2 was determined using the weighted Spearman correlation coefficient.

MAIN RESULTS

Data of 493 cases were obtained. Of these, 267 were excluded for various reasons. Finally, 226 cases with a total of 645 samples were analyzed. The median FiO2 was 36% (IQR 31 to 43), with a range from 20% to 97%, and the median PaO2 was 23.6 kPa (IQR 18.6 to 28.1); 177 mmHg (IQR 140 to 211). The median SpO2 level was 99% (IQR 98 to 100%). The study showed a moderately positive association between PaO2 and FiO2 (r = 0.52, p < 0.001). 574 of 645 samples (89%) contained a PaO2 higher than 13.3 kPa; 100 mmHg.

CONCLUSIONS

Oxygen administration during general pediatric anesthesia is barely regulated. Hyperoxemia is observed intraoperatively in approximately 90% of cases. Future research should focus on outcomes related to hyperoxemia.

EpiDiP/NanoDiP: a versatile unsupervised machine learning edge computing platform for epigenomic tumour diagnostics

DNA methylation analysis based on supervised machine learning algorithms with static reference data, allowing diagnostic tumour typing with unprecedented precision, has quickly become a new standard of care. Whereas genome-wide diagnostic methylation profiling is mostly performed on microarrays, an increasing number of institutions additionally employ nanopore sequencing as a faster alternative. In addition, methylation-specific parallel sequencing can generate methylation and genomic copy number data. Given these diverse approaches to methylation profiling, to date, there is no single tool that allows (1) classification and interpretation of microarray, nanopore and parallel sequencing data, (2) direct control of nanopore sequencers, and (3) the integration of microarray-based methylation reference data. Furthermore, no software capable of entirely running in routine diagnostic laboratory environments lacking high-performance computing and network infrastructure exists. To overcome these shortcomings, we present EpiDiP/NanoDiP as an open-source DNA methylation and copy number profiling suite, which has been benchmarked against an established supervised machine learning approach using in-house routine diagnostics data obtained between 2019 and 2021. Running locally on portable, cost- and energy-saving system-on-chip as well as gpGPU-augmented edge computing devices, NanoDiP works in offline mode, ensuring data privacy. It does not require the rigid training data annotation of supervised approaches. Furthermore, NanoDiP is the core of our public, free-of-charge EpiDiP web service which enables comparative methylation data analysis against an extensive reference data collection. We envision this versatile platform as a useful resource not only for neuropathologists and surgical pathologists but also for the tumour epigenetics research community. In daily diagnostic routine, analysis of native, unfixed biopsies by NanoDiP delivers molecular tumour classification in an intraoperative time frame.

Intraoperative tourniquet-induced hyperthermia in a pediatric patient: a forgotten association

Background

The intraoperative use of tourniquets is associated with several complications, including hyperthermia. We present the first documented case of tourniquet-induced hyperthermia in a pediatric patient at our institution.

Case

A 5-year-old female with no past medical history underwent tendon release surgery for congenital talipes equinovarus under general anesthesia. Following inflation of a pneumatic tourniquet to a pressure of 250 mmHg on her left thigh, the patient experienced a gradual increase in body temperature. Despite the implementation of cooling measures, the temperature continued to increase until it plateaued. The hyperthermia gradually resolved upon deflation of the tourniquet.

Conclusions

Tourniquet-induced hyperthermia should be considered as a potential cause of intraoperative hyperthermia, particularly in the absence of typical signs of malignant hyperthermia. Early recognition and appropriate management, including deflation of the tourniquet and implementation of cooling measures, are crucial for preventing potential complications associated with hyperthermia.

Rapid Passive Gamma Mapping as an Adjunct to Electrical Stimulation Mapping for Functional Localization in Resection of Primary Brain Neoplasms

OBJECTIVE

We examined the utility of passive high gamma mapping (HGM) as an adjunct to conventional awake brain mapping during glioma resection. We compared functional and survival outcomes before and after implementing intraoperative HGM.

METHODS

This was a retrospective cohort study of 75 patients who underwent a first-time, awake craniotomy for glioma resection. Patients were stratified by whether their operation occurred before or after the implementation of a U.S. Food and Drug Administration-approved high-gamma mapping tool in July 2017.

RESULTS

The preimplementation and postimplementation cohorts included 28 and 47 patients, respectively. Median intraoperative time (261 vs. 261 minutes, P = 0.250) and extent of resection (97.14% vs. 98.19%, P = 0.481) were comparable between cohorts. Median Karnofsky performance status at initial follow-up was similar between cohorts (P = 0.650). Multivariable Cox regression models demonstrated an adjusted hazard ratio for overall survival of 0.10 (95% confidence interval: 0.02-0.43, P = 0.002) for the postimplementation cohort relative to the preimplementation cohort. Progression-free survival adjusted for insular involvement showed an adjusted hazard ratio of 1.00 (95% confidence interval: 0.49-2.06, P = 0.999) following HGM implementation. Falling short of statistical significance, prevalence of intraoperative seizures and/or afterdischarges decreased after HGM implementation as well (12.7% vs. 25%, P = 0.150).

CONCLUSIONS

Our results tentatively indicate that passive HGM is a safe and potentially useful adjunct to electrical stimulation mapping for awake cortical mapping, conferring at least comparable functional and survival outcomes with a nonsignificant lower rate of intraoperative epileptiform events. Considering the limitations of our study design and patient cohort, further investigation is needed to better identify optimal use cases for HGM.

Transthoracic Echocardiography Is Possible in Morbidly Obese Patients During Bariatric Surgery

BACKGROUND

To evaluate the feasibility of an abbreviated focus-assessed transthoracic echocardiography protocol in morbidly obese patients. The purpose of this study was to evaluate whether good images could be obtained from this particularly difficult group of patients for whom acoustic imaging is often poor. Heart imaging could be helpful for cardiopulmonary screening and real-time monitoring.

METHODS

The study included 186 morbidly obese patients, who underwent laparoscopic bariatric surgery. The mean patient age was 32 years (range 21-52), and there were 95 males. The parasternal long and short axes and apical 4 and 5 chambers were evaluated.

RESULTS

In 95% of the patients, at least one view was obtained. In 78%, two views were obtained, and in 31% of the patients, all views and measurements could be performed.

CONCLUSION

In obese patients, a modified focused echocardiography examination performed by anesthesiologists in the intraoperative period of morbid obese patients is feasible. The image quality was sufficient to undergo interpretation.

Systematic review of intraoperative corticosteroid injections and the risk of infection in arthroscopic surgery

Background

Despite the fact that preoperative corticosteroid injections within three to six months of surgery increase the risk of postoperative infection, there is a growing trend of using corticosteroid injections intraoperatively as an effort to decrease postoperative pain and opiate use. Our aim with this review was to answer the question "Do intraoperative corticosteroid injections increase the risk of infections in arthroscopic surgery?"

Methods

A systematic search of MEDLINE, Cochrane, and PMC databases was conducted adhering to PRISMA 2020 guidelines after registration with PROSPERO (ID: CRD42023459138). We included studies comparing infection rates in patients who received intraoperative corticosteroid injections (IOCSI) to those who received no injection. The MINORS risk of bias tool was used to assess the quality of included studies.

Results

305 individual records were screened and a total of 8 studies met the criteria for inclusion in the study, containing data from over 700,000 patient records. All 7 retrospective studies showed an increase in infection rates and the single small randomized controlled trial had no infections in either the control or intervention group. The combined weighted odds ratio of infection rates in comparable studies was 2.23 95% CI (1.66-3.11).

Conclusions

Current data shows that IOCSIs more than double the risk of postoperative infection during arthroscopic surgery. Surgeons should consider and weigh the impact of infection to the minor clinical benefit corticosteroid injections add over other multimodal injections. We expect similar increases in infection rates in other surgeries where IOCSIs are used due to the inherent immunosuppressive mechanisms of corticosteroids.

Intraoperative Medial Instability During Total Knee Arthroplasty

A review article summarizes the existing literature on intraoperative injury to medial collateral ligament (MCL) during total knee arthroplasty (TKA), methods of fixation, repair, and the outcomes after these injuries. The options for increasing implant constraint and repair of the MCL injury are discussed with the potential indications for each. There is also a review of risk factors for MCL injury during TKA to help anticipate potential issues preoperatively. The proper use of retractors during total knee replacement is also discussed with a focus on careful protection of the MCL during surgery.

Is Intraoperative CT Navigation feasible for excision of osteoid osteoma in the appendicular skeleton? - Retrospective analysis of 58 cases

Background

The use of intraoperative CT navigation to manage osteoid osteoma is not common. We report our experience managing osteoid osteoma in the appendicular skeleton using an intraoperative AIRO CT navigation system.

Materials & methods

Between May 2013 and December 2022, 59 patients underwent Navigation-assisted excision of osteoid osteoma in the appendicular skeleton. Our primary study outcome was to assess for recurrence of the tumour with recurrence of symptoms. For our secondary outcomes, we evaluated the complications associated with the procedure and evaluated the histological slides of all patients to see for the presence of nidus.

Results

Of the 58 patients available for review, no patient had a lesion recurrence, and all were symptom-free at an average follow-up of 45.6 months (6-100). Two patients (3.5%) had a superficial infection managed conservatively, and 43 patients (74.1%) had the presence of nidus in curetted samples. No patient developed a pathological fracture after the procedure.

Conclusion

Using intraoperative CT navigation to manage osteoid osteoma in the appendicular skeleton is safe, minimally invasive, and effective in completely removing the nidus with a negligible complication rate. The absence of nidus on histology should not be a concern to clinicians once thorough burring and verification of excision of nidus has been confirmed intra-operatively.

Study design

Retrospective Case Series.

Level of evidence

Level IV.

Characterizing the molecular epidemiology of anaesthesia work area transmission of Staphylococcus aureus sequence type 5

BACKGROUND

Staphylococcus aureus sequence type 5 (ST5) is an emerging global threat.

AIM

To characterize the epidemiology of ST5 transmission in the anaesthesia work area.

METHODS

The retrospective cohort study analysed transmitted, prophylactic antibiotic-resistant Staphylococcus aureus isolates involving anaesthesia work area reservoirs. Using whole-genome analysis, the epidemiology of ST5 transmission was characterized by reservoir(s) of origin, transmission location(s), portal of entry, and mode(s) of transmission. All patients were followed for at least 30 days for surgical site infection (SSI) development.

FINDINGS

Forty-one percent (18/44; 95% confidence interval: 28-56%) of isolates were ST5. Provider hands were the reservoir of origin for 28% (5/18) of transmitted ST5 vs 4% (1/26) for other STs. Provider hands were the transmission location for 28% (5/18) of ST5 vs 7% (2/26) of other STs. Stopcock contamination occurred for 8% (1/13) of ST5 isolates vs 12% (3/25) of other STs. Sixty-three percent of transmission events occurring between cases on separate operative dates involved ST5. ST5 was more likely to harbour resistance traits (ST5 median (interquartile range) 3 (2-3) vs 2 (1-2) other STs; P < 0.001) and had greater resistance to cefazolin, piperacillin-tazobactam, and/or ciprofloxacin (ST5: 3 (2-3) vs 2 (1-3) other STs; P = 0.02). ST5 was associated with three of six SSIs.

CONCLUSION

ST5 is prevalent among transmitted, prophylactic antibiotic-resistant isolates in the anaesthesia work area. Transmission involves provider hands and one patient to another on future date(s). ST5 is associated with a greater number of resistance traits and reduced in-vitro susceptibility vs other intraoperative meticillin-resistant S. aureus.

Case series and updated literature review

BACKGROUND

Intraoperative pulmonary embolism (PE) with cardiac arrest (CA) represents a critical and potentially fatal condition. Available treatments include systemic thrombolysis, catheter-based thrombus fragmentation or aspiration, and surgical embolectomy. However, limited studies are focused on the optimal treatment choice for this critical condition. We present a case series and an updated review of the management of intraoperative CA secondary to PE.

METHODS

A retrospective review of patients who developed high-risk intraoperative PE was performed between June 2012 and June 2022. For the updated review, a literature search on PubMed and Scopus was conducted which resulted in the inclusion of a total of 46 articles.

RESULTS

A total of 196 174 major non-cardiac surgeries were performed between 2012 and 2022. Eight cases of intraoperative CA secondary to high-risk PE were identified. We found a mortality rate of 75%. Anticoagulation therapy was administered to one patient (12.5%), while two patients (25%) underwent thrombolysis, and one case (12.5%) underwent mechanical thrombectomy combined with thrombus aspiration. Based on the literature review and our 10-year experience, we propose an algorithm for the management of intraoperative CA caused by PE.

CONCLUSION

The essential components for adequate management of intraoperative PE with CA include hemodynamic support, cardiopulmonary resuscitation, and the implementation of a primary perfusion intervention. The prompt identification of the criteria for each specific treatment modality, guided by the individual patient's characteristics, is necessary for an optimal approach.

The role of intraoperative pancreatoscopy in the surgical management of intraductal papillary mucinous neoplasms of the pancreas: a systematic scoping review

BACKGROUND

The type and the extent of surgery is still debatable for intraductal papillary mucinous neoplasm (IPMN). Intraoperative pancreatoscopy (IOP) allows the visualization of the main pancreatic duct (MPD) in its entire length and could help determine the extent of MPD involvement and the type and extent of pancreatic resection. However, current guidelines do not advise its routine use as there is a lack of evidence supporting its safety and feasibility. The present study aims to perform a scoping review of published evidence on the safety and feasibility of IOP in IPMN surgical management.

METHODS

We systematically searched PubMed, Cochrane, Medline and EMbase to identify studies reporting the use of IOP in IPMN surgical management. The research was completed in June 2023. Data extracted included patient selection criteria, demographics, safety of the procedure, intraoperative findings, impact on surgical strategy, histology results and postoperative outcomes.

RESULTS

Four retrospective and one prospective study were included in this scoping review. A total of 142 patients had IOP. The selection criteria for inclusion were heterogenous, with one out of five studies including branch duct (BD), main duct (MD) and mixed type IPMN. Indications for IOP and surgical resection were only reported in two studies. A median of seven outcomes (range 5-8) was described, including the type of surgical resection, additional lesions and change of surgical plan, and complications after IOP. IOP showed additional lesions in 48 patients (34%) and a change of surgical plan in 48(34%). No IOP-related complications were reported.

CONCLUSIONS

This scoping review suggests IOP is safe and identifies additional lesions impacting the surgical strategy for IPMN. However, the included studies were small and heterogeneous regarding IPMN definition and indications for surgery and IOP. There is a need for a large multi-centre prospective study to determine the role of IOP and its impact on surgical strategy for IPMN.

A Novel Intraoperative Posture-Adjustment Apparatus for Correction of Cervical Lordosis in Anterior Cervical Surgery

OBJECTIVE

Cervical alignment is a crucial factor related to the success of anterior cervical surgical procedures. In patients with severe spinal cord compression, a traditional neck pillow (TNP) may not adequately correct cervical position during surgery. Therefore, the aim of this study was to introduce this innovative intraoperative posture-adjustment apparatus (IPAA), and explored its clinical and radiological results in cervical angle correction against TNP in patients who had undergone anterior cervical surgery.

METHODS

The clinical and radiological data of 86 patients who underwent anterior cervical surgery with a minimum follow-up period of 1 year were retrospectively reviewed. Of these, 58 patients underwent IPAA, whereas 28 underwent TNP. Radiological parameters such as the degree of C2-C7 lordosis (CL), functional spinal unit angle (FSUA), C7 slope (C7S), fusion rate, and adjacent segment disease (ASD) were recorded and compared between the groups. Clinical outcomes including the Japanese Orthopaedic Association (JOA), neck disability index (NDI), visual analogue scale (VAS) for neck and arm were recorded. Complications such as kyphosis, dysphagia, Braden Scale score, revision surgery, hematoma, cerebrospinal fluid leakage, wound infection, and deep venous thrombosis were also recorded. The independent t-test or Mann-Whitney U test was used to compare continuous data, and categorical variables were assessed using the Pearson's chi-square test or Fisher's exact test.

RESULTS

Compared with the pre-operative data, the post-operative CL, FSUA, and C7S were significantly increased in both groups. CL, FSUA, and C7S in the IPAA group (14.44 ± 4.94°, 7.36 ± 2.91°, 16.54 ± 4.63°) were significantly higher than those in the TNP group (7.17 ± 8.19°, 4.99 ± 5.36°, 14.19 ± 4.48°; P < 0.05). Although there were no significant differences between the groups in terms of VAS arm and JOA scores, the post-operative and final follow-up NDI and VAS neck scores in the IPAA group were significantly lower than those in the TNP group (p < 0.05). At the last follow-up, the TNP group had significantly more kyphotic patients than the IPAA group (2 vs. 0, p = 0,041). There was no significant difference between the groups in terms of fusion rate, ASD, or complications such as dysphagia, Braden's Scale score, revision surgery, hematoma, cerebrospinal fluid leakage, wound infection, or deep venous thrombosis.

CONCLUSION

IPAA was shown to be more effective than TNP in adjusting cervical alignment (CL, FSUA, and C7S). These findings suggest that IPAA could be used as an alternative way to TNP in neck setting and cervical alignment adjustment and IPAA could potentially improve clinical outcomes after anterior cervical surgery.

Deep Learning-Based Intraoperative Stent Graft Segmentation on Completion Digital Subtraction Angiography During Endovascular Aneurysm Repair

PURPOSE

Modern endovascular hybrid operating rooms generate large amounts of medical images during a procedure, which are currently mostly assessed by eye. In this paper, we present fully automatic segmentation of the stent graft on the completion digital subtraction angiography during endovascular aneurysm repair, utilizing a deep learning network.

TECHNIQUE

Completion digital subtraction angiographies (cDSAs) of 47 patients treated for an infrarenal aortic aneurysm using EVAR were collected retrospectively. A two-dimensional convolutional neural network (CNN) with a U-Net architecture was trained for segmentation of the stent graft from the completion angiographies. The cross-validation resulted in an average Dice similarity score of 0.957 ± 0.041 and median of 0.968 (IQR: 0.950 - 0.976). The mean and median of the average surface distance are 1.266 ± 1.506 mm and 0.870 mm (IQR: 0.490 - 1.430), respectively.

CONCLUSION

We developed a fully automatic stent graft segmentation method based on the completion digital subtraction angiography during EVAR, utilizing a deep learning network. This can provide the platform for the development of intraoperative analytical applications in the endovascular hybrid operating room such as stent graft deployment accuracy, endoleak visualization, and image fusion correction.

Use of intraoperative bone scintigraphy for resection of spinal osteoid osteoma

BACKGROUND

The location and proximity to the spinal cord in spinal osteoid osteoma can increase the likelihood of an incomplete resection. Intraoperative bone scintigraphy (IOBS) can be used to verify location and complete surgical resection.

OBJECTIVE

To review our experience using IOBS for resection of intraspinal osteoid osteoma.

METHODS

IRB approved, retrospective review of IOBS-guided resection over 10 years. Patients underwent injection of 200 uCi/kg (1-20 mCi) 99mTc-MDP 3-4 h prior surgery. Portable single-headed gamma camera equipped with a pinhole collimator (3- or 4-mm aperture) was used. Images were obtained pre-operatively, at the start of the procedure, and intraoperatively. Operative notes were reviewed. Evaluation of recurrence and clinical follow-up was performed.

RESULTS

Twenty IOBS-guided resections were performed in 18 patients (median age 13.5 years, 6-22 years, 12 males). Size ranged 5-16 mm, with 38.9% (7/18) cervical, 22.2% (4/18) thoracic, 22.2% (4/18) lumbar, and 16.7% (3/18) sacral. In all cases, IOBS was able to localize the lesion. After suspected total excision, IOBS altered the surgical plan in 75% of cases (15/20), showing residual activity prompting further resection. Median length of follow-up was 6 months (range 1-156 months) with 90% (18/20) showing complete resection without recurrence. Two patients had osteoid osteoma recurrence at 7 and 10 months following the original resection, requiring re-intervention.

CONCLUSIONS

IOBS is a useful tool for real-time localization and assessment of spinal osteoid osteoma resection. In all cases, IOBS was able to localize the lesion and changed surgical planning in 75% of cases. Ninety percent of patients achieved complete resection and remain recurrence free.

Aortic valve visualization and pressurization device: a novel device for intraoperative evaluation of aortic valve repair procedures

OBJECTIVES

Aortic valve repair procedures are technically challenging, and current intraoperative evaluation methods often fail to predict the final echocardiographic result. We have developed a novel intraoperative aortic valve visualization and pressurization (AVP) device, enabling valve inspection under physiological conditions, and measuring aortic valve insufficiency (AI) during cardioplegic arrest.

METHODS

The AVP device is attached to the (neo)aorta, after any type of aortic valve repair, while the heart is arrested. The root is pressurized (60-80 mmHg) using a saline solution and an endoscope is introduced. The valve is inspected, and the amount of valvular leakage is measured. Postoperative 'gold standard' transesophageal echocardiogram measurements of AI are performed and compared against regurgitation volume measured.

RESULTS

In 24 patients undergoing valve-sparing root replacement, the AVP device was used. In 22 patients, postoperative echocardiographic AI was ≤ grade 1. The median leakage was 90 ml/min, IQR 60-120 ml/min. In 3 patients, additional adjustments after visual inspection was performed. In 2 patients, with complex anatomy, the valve was replaced. In one, after evaluation with the device, there was undesirable result visually and residual AI of 330 ml/min, and in another, 260 ml/min residual AI was measured and valve restriction on visual inspection.

CONCLUSIONS

The novel AVP device enables intraoperative evaluation of the valve under physiological conditions, while still on arrested heart, and allows for targeted adjustments. The AVP device can be an important aid for intraoperative evaluation of the aortic valve, during valve repair and valve-sparing procedures, thereby making the operative result more predictable and the operation more efficient.

Left atrial appendage thrombus in an elderly patient with atrial fibrillation during non-cardiac surgery- a case report

BACKGROUND

Perioperative newly developed left atrial appendage (LAA) thrombus is a rare but extremely challenging event for anesthesia management. It's important to identify and diagnose thrombosis in high-risk populations promptly.

CASE PRESENTATION

In the case of an elderly patient with atrial fibrillation undergoing non-cardiac surgery, we recorded the findings before and after thrombosis during the operation using transesophageal echocardiography (TEE). Through timely detection of the thrombus and proactive management, a satisfactory therapeutic effect was ultimately achieved.

CONCLUSIONS

Clinicians should be aware of the potential risk of LAA clot formation during surgery, even if it was not detected preoperatively. And TEE is valuable for monitoring newly developed perioperative thrombosis.

Intraoperative use of low-field magnetic resonance imaging for brain tumors: A systematic review

Background

Low-field magnetic resonance imaging (LF-MRI) has become a valuable tool in the diagnosis of brain tumors due to its high spatial resolution and ability to acquire images in a short amount of time. However, the use of LF-MRI for intraoperative imaging during brain tumor surgeries has not been extensively studied. The aim of this systematic review is to investigate the impact of low-field intraoperative magnetic resonance imaging (LF-IMRI) on the duration of brain tumor surgery and the extent of tumor resection.

Methods

A comprehensive literature search was conducted using PubMed, Scopus, and Google Scholar from February 2000 to December 2022. The studies were selected based on the inclusion criteria and reviewed independently by two reviewers. The gathered information was organized and analyzed using Excel.

Results

Our review of 21 articles found that low-field intraoperative MRI (LF-IMRI) with a field below 0.3T was used in most of the studies, specifically 15 studies used 0.15T LF-IMRI. The T1-weighted sequence was the most frequently reported, and the average scanning time was 24.26 min. The majority of the studies reported a positive impact of LF-IMRI on the extent of tumor resection, with an increase ranging from 11% to 52.5%. Notably, there were no studies describing the use of ultra-low-field (ULF) intraoperative MRI.

Conclusion

The results of this systematic review will aid neurosurgeons and neuroradiologists in making informed decisions about the use of LF-MRI in brain tumor surgeries. Further, research is needed to fully understand the impact of LF-MRI in brain tumor surgeries and to optimize its use in the clinical setting. There is an opportunity to study the utility of ULF-MRI in brain tumor surgeries.

Preoperative Tricuspid Regurgitation Is Associated With Long-Term Mortality and Is Graded More Severe Than Intraoperative Tricuspid Regurgitation

OBJECTIVES

To determine whether preoperative (preop) tricuspid regurgitation (TR) severity grade was associated with postoperative mortality, to examine the correlation between pre-op and intraoperative (intraop) TR grades, and to understand which TR grade had better prognostic predictability in cardiac surgery patients.

DESIGN

Retrospective.

SETTING

Single institution.

PARTICIPANTS

Patients.

INTERVENTIONS

Preop and intraop echocardiography TR grades of 4,232 patients who had undergone cardiac surgeries between 2004 and 2014 were examined.

MEASUREMENTS AND MAIN RESULTS

Kaplan-Meier curves and Cox proportional hazard models were used to determine the association between TR grades and the primary endpoint of all-cause mortality. The Wilcoxon signed-rank test and Spearman's rank correlation were analyzed to assess the similarity and correlation between preop and intraop-grade pairs. Multivariate logistic regression models of the area under the curve characteristics were compared for prognostic implications. Kaplan-Meier curves demonstrated a strong relationship between preop grades and survival. Multivariate models showed significantly increased mortality starting at mild preop TR (mild TR: hazard ratio [HR] 1.24; 95% CI 1.05-1.46, p = 0.013; moderate TR: HR 1.60; 95% CI 1.05-1.97, p < 0.001; severe TR: HR 2.50; 95% CI 1.74-3.58, p < 0.001). Preop TR grades were mostly higher than intraop grades. Spearman's correlation was 0.55 (p < 0.001). The area under the curves of preop and intraop TR-based models were almost identical (0.704 v 0.702 1-year mortality and 0.704 v 0.700 2-year mortality).

CONCLUSIONS

The authors found that echocardiographically-determined preop TR grade at the time of surgical planning was associated with long-term mortality, starting even at a mild grade. Preop grades were higher than intraop grades, with a moderate correlation. Preop and intraop grades exhibited similar prognostic implications.

American Society of Biomechanics Journal of Biomechanics Award 2022: Computer models do not accurately predict human muscle passive muscle force and fiber length: Evaluating subject-specific modeling impact on musculoskeletal model predictions

Musculoskeletal models are valuable for studying and understanding the human body in a variety of clinical applications that include surgical planning, injury prevention, and prosthetic design. Subject-specific models have proven to be more accurate and useful compared to generic models. Nevertheless, it is important to validate all models when possible. To this end, gracilis muscle-tendon parameters were directly measured intraoperatively and used to test model predictions. The aim of this study was to evaluate the benefits and limitations of systematically incorporating subject-specific variables into muscle models used to predict passive force and fiber length. The results showed that incorporating subject-specific values generally reduced errors, although significant errors still existed. Optimization of the modeling parameter "tendon slack length" was explored in two cases: minimizing fiber length error and minimizing passive force error. The results showed that using all subject-specific values yielded the most favorable outcome in both models and optimization cases. However, the trade-off between fiber length error and passive force error will depend on the specific circumstances and research objectives due to significant individual errors. Notably, individual fiber length and passive force errors were as high as 20% and 37% respectively. Finally, the modeling parameter "tendon slack length" did not correlate with any real-world anatomical length.

Intraoperative neurophysiological monitoring in scoliosis surgery: literature review of the last 10 years

INTRODUCTION

Patients with spinal deformities undergoing corrective surgery are at risk for iatrogenic spinal cord injury (SCI) and subsequent neurological deficit. Intraoperative neurophysiological monitoring (IONM) allows early detection of SCI which enables early intervention resulting in a better prognosis. The primary aim of this literature review was to search if there are threshold values of TcMEP and SSEP in the literature that are widely accepted as alert during IONM. The secondary aim was to update knowledge concerning IONM during scoliosis surgery.

METHOD

PubMed/MEDLINE and Cochrane library electronic databases were used to search publication from 2012 to 2022. The following keywords were used: evoked potential, scoliosis, surgery, intraoperative monitoring and neurophysiological. We included all studies dealing with SSEP and TcMEP monitoring during scoliosis surgery. Two authors reviewed all titles and abstracts to identify studies that met the inclusion criteria.

RESULTS

We included 43 papers. Rates of IONM alert and neurological deficit varied from 0.56 to 64% and from 0.15 to 8.3%, respectively. Threshold values varied from a loss of 50 to 90% for TcMEP amplitude, whereas it seems that a loss of 50% in amplitude and/or an increase of 10% of latency is widely accepted for SSEP. Causes of IONM changes most frequently reported were surgical maneuver.

CONCLUSION

Concerning SSEP, a loss of 50% in amplitude and/or an increase of 10% of latency is widely accepted as an alert. For TcMEP, it seems that the use of highest threshold values can avoid unnecessary surgical procedure for the patient without increasing risk of neurological deficit.

Intraoperative accidental hypothermia as a probable cause of malignant ventricular arrhythmias in an elderly patient undergoing transurethral resection of prostate: A case report

Background

Intraoperative hypothermia is a common but severe condition that is defined as a core body temperature below 36 °C. Accidental hypothermia can produce coagulopathy, immunosuppression and peripheral hypoperfusion that can ultimately lead to life-threatening ventricular arrhythmias and vital organ injury, and it is significantly associated with perioperative complications and mortality.

Case description

We report the case of an 82-year-old man who presented with persistent ventricular tachycardia intraoperatively due to accidental hypothermia. The patient was diagnosed with benign prostatic hypertrophy and scheduled for transurethral resection of the prostate. Laboratory tests showed moderate anemia, and echocardiography indicated mild tricuspid and mitral regurgitation. The patient received general anesthesia with endotracheal intubation. Four hours after the start of surgery, the patient developed sudden ventricular tachycardia with severe hypotension. Arterial blood gas sampling indicated that there was no disturbance of electrolytes, acid-base balance or excessive bleeding. The rectal temperature was measured immediately, and the core temperature was 32 °C. The patient received antiarrhythmic therapy and rewarming measures. No additional ventricular arrhythmias appeared after the core temperature rose to 35 °C and the blood pressure returned to normal. The patient was transferred to the intensive care unit after surgery for further observation and was moved to the general ward the next day. He was discharged 4 days later without significant organ damage.

Conclusions

Intraoperative hypothermia may increase ventricular arrhythmia risk, especially in elderly patients. Surgeons and anesthesiologists should pay more attention to preventing and reversing accidental hypothermia, necessitating aggressive efforts to maintain normothermia during surgery.

Association of the classification of intraoperative adverse events (ClassIntra) with complications and neurological outcome after neurosurgical procedures: a prospective cohort study

PURPOSE

To analyze the reliability of the classification of intraoperative adverse events (ClassIntra) to reflect intraoperative complications of neurosurgical procedures and the potential to predict the postoperative outcome including the neurological performance. The ClassIntra classification was recently introduced and found to be reliable for assessing intraoperative adverse events and predicting postoperative complications across different surgical disciplines. Nevertheless, its potential role for neurosurgical procedures remains elusive.

METHODS

This is a prospective, monocentric cohort study assessing the ClassIntra in 422 adult patients who underwent a neurosurgical procedure and were hospitalized between July 1, 2021, to December 31, 2021. The primary outcome was the occurrence of intraoperative complications graded according to ClassIntra and the association with postoperative outcome reflected by the Clavien-Dindo classification and comprehensive complication index (CCI). The ClassIntra is defined as intraoperative adverse events as any deviation from the ideal course on a grading scale from grade 0 (no deviation) to grade V (intraoperative death) and was set at sign-out in agreement between neurosurgeon and anesthesiologist. Secondary outcomes were the neurological outcome after surgery as defined by Glasgow Coma Scale (GCS), modified Rankin scale (mRS), Neurologic Assessment in Neuro-Oncology (NANO) scale, National Institute Health of Strokes Scale (NIHSS), and Karnofsky Performance Score (KPS), and need for unscheduled brain scan.

RESULTS

Of 442 patients (mean [SD] age, 56.1 [16.2]; 235 [55.7%] women and 187 [44.3%] men) who underwent a neurosurgical procedure, 169 (40.0%) patients had an intraoperative adverse event (iAE) classified as ClassIntra I or higher. The NIHSS score at admission (OR, 1.29; 95% CI, 1.03-1.63, female gender (OR, 0.44; 95% CI, 0.23-0.84), extracranial procedures (OR, 0.17; 95% CI, 0.08-0.61), and emergency cases (OR, 2.84; 95% CI, 1.53-3.78) were independent risk factors for a more severe iAE. A ClassIntra ≥ II was associated with increased odds of postoperative complications classified as Clavien-Dindo (p < 0.01), neurological deterioration at discharge (p < 0.01), prolonged hospital (p < 0.01), and ICU stay (p < 0.01). For elective craniotomies, severity of ClassIntra was associated with the CCI (p < 0.01) and need for unscheduled CT or MRI scan (p < 0.01). The proportion of a ClassIntra ≥ II was significantly higher for emergent craniotomies (56.2%) and associated with in-hospital mortality, and an unfavorable neurological outcome (p < 0.01).

CONCLUSION

Findings of this study suggest that the ClassIntra is sensitive for assessing intraoperative adverse events and sufficient to identify patients with a higher risk for developing postoperative complications after a neurosurgical procedure.

Combined and intraoperative risk modelling for oesophagectomy: A systematic review

BACKGROUND

Oesophageal cancer is the eighth most common malignancy worldwide and is associated with a poor prognosis. Oesophagectomy remains the best prospect for a cure if diagnosed in the early disease stages. However, the procedure is associated with significant morbidity and mortality and is undertaken only after careful consideration. Appropriate patient selection, counselling and resource allocation is essential. Numerous risk models have been devised to guide surgeons in making these decisions.

AIM

To evaluate which multivariate risk models, using intraoperative information with or without preoperative information, best predict perioperative oesophagectomy outcomes.

METHODS

A systematic review of the MEDLINE, EMBASE and Cochrane databases was undertaken from 2000-2020. The search terms used were [(Oesophagectomy) AND (Model OR Predict OR Risk OR score) AND (Mortality OR morbidity OR complications OR outcomes OR anastomotic leak OR length of stay)]. Articles were included if they assessed multivariate based tools incorporating preoperative and intraoperative variables to forecast patient outcomes after oesophagectomy. Articles were excluded if they only required preoperative or any post-operative data. Studies appraising univariate risk predictors such as preoperative sarcopenia, cardiopulmonary fitness and American Society of Anesthesiologists score were also excluded. The review was conducted following the preferred reporting items for systematic reviews and meta-analyses model. All captured risk models were appraised for clinical credibility, methodological quality, performance, validation and clinical effectiveness.

RESULTS

Twenty published studies were identified which examined eleven multivariate risk models. Eight of these combined preoperative and intraoperative data and the remaining three used only intraoperative values. Only two risk models were identified as promising in predicting mortality, namely the Portsmouth physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and POSSUM scores. A further two studies, the intraoperative factors and Esophagectomy surgical Apgar score based nomograms, adequately forecasted major morbidity. The latter two models are yet to have external validation and none have been tested for clinical effectiveness.

CONCLUSION

Despite the presence of some promising models in forecasting perioperative oesophagectomy outcomes, there is more research required to externally validate these models and demonstrate clinical benefit with the adoption of these models guiding postoperative care and allocating resources.

Imaging and photodynamic therapy of prostate cancer using a theranostic PSMA-targeting ligand

PURPOSE

Incomplete resection of prostate cancer (PCa) results in increased risk of disease recurrence. Combined fluorescence-guided surgery with tumor-targeted photodynamic therapy (tPDT) may help to achieve complete tumor eradication. We developed a prostate-specific membrane antigen (PSMA) ligand consisting of a DOTA chelator for 111In labeling and a fluorophore/photosensitizer IRDye700DX (PSMA-N064). We evaluated the efficacy of PSMA-tPDT using PSMA-N064 in cell viability assays, a mouse xenograft model and in an ex vivo incubation study on fresh human PCa tissue.

METHODS

In vitro, therapeutic efficacy of PSMA-N064 was evaluated using PSMA-positive LS174T cells and LS174T wild-type cells. In vivo, PSMA-N064-mediated tPDT was tested in immunodeficient BALB/c mice-bearing PSMA-positive LS174T xenografts. Tumor growth and survival were compared to control mice that received either NIR light or ligand injection only. Ex vivo tPDT efficacy was evaluated in excised fresh human PCa tissue incubated with PSMA-N064.

RESULTS

In vitro, tPDT led to a PSMA-specific light- and ligand dose-dependent loss in cell viability. In vivo, tPDT-induced tumor cell apoptosis, delayed tumor growth, and significantly improved survival (p = 0.004) of the treated PSMA-positive tumor-bearing mice compared with the controls. In fresh ex vivo human PCa tissue, apoptosis was significantly increased in PSMA-tPDT-treated samples compared to non-treated control samples (p = 0.037).

CONCLUSION

This study showed the feasibility of PSMA-N064-mediated tPDT in cell assays, a xenograft model and excised fresh human PCa tissue. This paves the way to investigate the impact of in vivo PSMA-tPDT on surgical outcome in PCa patients.

Oblique radiograph with methylene blue marking: A reliable technique for upper thoracic level localization

Purpose

Traditionally, plain radiographs are used in intraoperative spinal level localization (SLL), whereas counting vertebrae is often hampered by shoulders and scapulae in lateral views, thus increasing the potential for wrong-level surgery. To improve the localization accuracy, this study evaluated the safety and feasibility of oblique radiographs with methylene blue markings for SLL and explored the optimal angle and height of oblique radiographs.

Methods

The clinical data of 33 patients with upper thoracic spine lesions who were operated on in our hospital from January 2021 to April 2022 were retrospectively analyzed. Oblique radiographs with methylene blue markings were used for intraoperative SLL.

Results

A total of 33 patients were included in this study. The average BMI was 24.3 ± 0.7 kg/m². The ipsilateral lamina structures were clearly shown in all cases. The median radiographing times of all the patients was 3, and the median radiographing duration was 2 min and 25 s. The average angle of oblique radiographs was 55.1 ± 3.8°, and the average distance from the skin to the root of the spinous process was 4.9 ± 1.2 cm.

Conclusions

Using oblique radiographs with methylene blue markings, not only the bone structure of an upper thoracic spine can be revealed clearly, but also the positioning deviation of traditional needle localization can be avoided. The lesion segment can be precisely located by this technology during surgery. Our angle of oblique radiographs and height determination method can be used to reduce the radiation exposure and shorten the operation time.

Intraoperative Inversion of the Left Atrial Appendage Following Ligation

•

Intraoperative TEE improves the diagnosis of LAA inversion.

•

Excess negative pressure causes inversion at predictable points in cardiac surgery.

•

Structural characteristics of the LAA may influence inversion susceptibility.

•

Ligation has been used to manage LAA inversion but may actually cause inversion.

•

This may occur from altering the structural characteristics and shortening the LAA.

Effect of Preoperative Dexamethasone on Postoperative Pain in Patients Undergoing Tonsillectomy

Tonsillectomy is one of the most commonly performed surgical procedures worldwide. Postoperative pain remains a significant problem for patients undergoing tonsillectomy and is the most typical reason for readmission after the procedure. We conducted the present study to investigate the efficacy of a single dose of dexamethasone administered intravenously before tonsillectomy on postoperative pain in a group of patients undergoing cold dissection tonsillectomy, using a standardised anaesthetic and surgical procedure.It was a prospective study done in the Department of ENT in a tertiary care centre in eastern India, from 1 st September 2017 to 31 st August 2019 (2 years). Subjects included in the study were patients who attended the OPD of ENT of the tertiary care centre in eastern India, with a history of throat pain,difficulty in deglutition, mouth breathing, snoring. Tonsillectomy operation was recommended to the patients who fit the inclusion criteria. A hundred patients were selected for the study and divided randomly into two groups. Patients in group A (50 patients) were administered preoperative intravenous dexamethasone (0.15 mg/kg)after the induction of anaesthesia, and Group B patients (50 patients)were not administered dexamethasone along with other drugs.RESULTS: A hundred patients were enrolled after excluding the patients not fulfilling the selection criteria. The majority of patients were female, with the majority patients between 9-19 years. There was a noteworthy decreased mean pain score postoperatively of Group A on the first, third, and fifth day. (p-value = < 0.001).The results of this study suggest that a single preoperative injection of dexamethasone for patients undergoing tonsillectomy by cold dissection method significantly reduced postoperative pain.

The Economic Impact of Standardization and Digitalization in the Operating Room: A Systematic Literature Review

Hospital face increased resource constraints and competition. This escalates the need for efficiency optimization especially in resource-intense areas, such as the Operating Room (OR). Efficiency cannot happen at expenses of patient outcomes. Innovative digital support systems (DSS) have been introduced into the market to support established standardization methods of intraoperative workflows further. This review aimed to analyze whether applied standardization methods and implemented DSS of intraoperative surgical workflows lead to increasing efficiency and demonstrate economic improvements. A systematic review of intraoperative surgical workflows standardization and digitalization was performed. Journal articles and reviews from 2000 to 2023 were retrieved from EBSCO, PubMed, and Scopus databases, as well as the internal database of Johnson & Johnson. 17 articles showed a significant increase in efficiency through standardization, which led to cost reductions between $70.20 to $3,516 per case without negatively impacting quality. Five additional articles on DSS demonstrated a significant positive impact on efficiency and quality. Reduction in OR-time between 6 to 22% per case was one main contributor. No literature on DSS revealed any correlated economic impact. Selected standardization methods and introduced DSS for intraoperative surgical workflows effectively increase efficiency while maintaining or even improving quality. Demonstrated cost-effectiveness of non-digital standardization methods across surgical areas requires more research on complex and resource-intensive procedures and the economic value of DSS to support hospital management's strategic decisions to overcome the increasing economic burden.

A randomized-controlled trial assessing the effect of intraoperative acupuncture on anesthesia-related parameters during gynecological oncology surgery

CONTEXT AND OBJECTIVES

The present study examined the impact of intraoperative acupuncture on anesthesia-related parameters in patients undergoing gynecological oncology surgery.

METHODS

Participants underwent preoperative integrative oncology (IO) touch/relaxation treatments, followed by intraoperative acupuncture (Group A); preoperative IO treatments without acupuncture (Group B); or standard care only (Group C). Mean arterial pressure (MAP), heart rate (HR), MAP variability (mean of MAP standard deviation), bispectral index (BIS), and calculated blood pressure Average Real Variability (ARV) were measured intraoperatively.

RESULTS

A total of 91 patients participated: Group A, 41; Group B, 24; Group C, 26. Among patients undergoing open laparotomy, Group A showed lower and more stable MAP and HR compared to Group B, (MAP, p = 0.026; HR, p = 0.029) and Group C (MAP, p = 0.025). Mean BIS, from incision to suture closing, was lower in Group A (vs. controls, p = 0.024). In patients undergoing laparoscopic surgery, MAP was elevated within Group A (p = 0.026) throughout surgery, with MAP variability significantly higher in Group A (P = 0.023) and Group B (P = 0.013) 10 min post-incision (vs. pre-incision). All groups showed similar intraoperative and post-anesthesia use of analgesic medication.

CONCLUSION

Intraoperative acupuncture was shown to reduce and stabilize MAP and HR, and reduce BIS in gynecology oncology patients undergoing laparotomy, with no impact on perioperative analgesic medication use. In the laparoscopic setting, intraoperative acupuncture was associated with elevated MAP. Further research is needed to explore the hemodynamic and BIS-associated benefits and risks of intraoperative acupuncture, and the impact on the use of analgesic drugs in response to these changes.

Retrospective cohort study of the impact of faecoliths on the natural history of acute appendicitis

BACKGROUND

Despite acute appendicitis is one of the most common surgical emergencies, its aetiology remains incompletely understood.

AIM

This study aimed to assess the rate at which faecoliths were present in acute appendicitis treated with appendicectomy and whether their presence was associated with complicated appendicitis.

METHODS

All adult patients who underwent appendicectomy for acute appendicitis in a 2 years period (January 2018 and December 2019) at a single institution were retrospectively reviewed. The presence of a faecolith was identified by at least one of three methods: pre-operative CT scan, intraoperative identification, or histopathology report. Patients were grouped according to the presence or absence of a faecolith and demographics, type of appendicitis and surgical outcomes analysed. Complicated appendicitis was defined as appendicitis with perforation, gangrene and/or periappendicular abscess formation.

RESULTS

A total of 1035 appendicectomies were performed with acute appendicitis confirmed in 860 (83%), of which 314 (37%) were classified as complicated appendicitis. Three hundred thirty-nine (35%) of the appendicitis cases had faecoliths (complicated 165/314 cases; 53%; uncomplicated 128/546; 23%, p < 0.001). The presence of a faecolith was associated with higher complications and a subsequent longer post-operative stay.

CONCLUSION

The rigorous methodology of this study has demonstrated a higher rate of faecolith presence in acute appendicitis than previously documented. It reinforces the association of faecoliths with a complicated disease course and the importance in prioritising emergency surgery and postoperative monitoring for complications.

Real-time quantification of intestinal perfusion and arterial versus venous occlusion using laser speckle contrast imaging in porcine model

PURPOSE

Real-time intraoperative perfusion assessment may reduce anastomotic leaks. Laser speckle contrast imaging (LSCI) provides dye-free visualization of perfusion by capturing coherent laser light scatter from red blood cells and displays perfusion as a colormap. Herein, we report a novel method to precisely quantify intestinal perfusion using LSCI.

METHODS

ActivSight™ is an FDA-cleared multi-modal visualization system that can detect and display perfusion via both indocyanine green imaging (ICG) and LSCI in minimally invasive surgery. An experimental prototype LSCI perfusion quantification algorithm was evaluated in porcine models. Porcine small bowel was selectively devascularized to create regions of perfused/watershed/ischemic bowel, and progressive aortic inflow/portal vein outflow clamping was performed to study arterial vs. venous ischemia. Continuous arterial pressure was monitored via femoral line.

RESULTS

LSCI perfusion colormaps and quantification distinguished between perfused, watershed, and ischemic bowel in all vascular control settings: no vascular occlusion (p < 0.001), aortic occlusion (p < 0.001), and portal venous occlusion (p < 0.001). LSCI quantification demonstrated similar levels of ischemia induced both by states of arterial inflow and venous outflow occlusion. LSCI-quantified perfusion values correlated positively with higher mean arterial pressure and with increasing distance from ischemic bowel.

CONCLUSION

LSCI relative perfusion quantification may provide more objective real-time assessment of intestinal perfusion compared to conventional naked eye assessment by quantifying currently subjective gradients of bowel ischemia and identifying both arterial/venous etiologies of ischemia.

The low sensitivity of direct smears limit the utility of intraoperative gram stains for predicting culture-positivity in acute surgical settings

The role of intraoperative Gram stains in acute surgery decision-making is unclear. Our retrospective chart review of microbiology results for specimens submitted by acute surgery attendings showed Gram stain performs with a sensitivity ranging from 18% to 65% compared to culture, depending on organism type, thus limiting its utility.

Side-Firing Intraoperative Ultrasonograhy for Resection of Giant Pituitary Adenomas

BACKGROUND

Suprasellar extension, cavernous sinus invasion, and involvement of intracranial vascular structures and cranial nerves are among the challenges faced by surgeons operating on giant pituitary macroadenomas. Intraoperative tissue shifts may render neuronavigation techniques inaccurate. Intraoperative magnetic resonance imaging can solve this problem, but it may be costly and time consuming. However, intraoperative ultrasonography (IOUS) allows for quick, real-time feedback and may be particularly useful when facing giant invasive adenomas. Here, we present the first study examining technique for IOUS-guided resection specifically focusing on giant pituitary adenomas.

OBJECTIVE

To describe the use of a side-firing ultrasound probe in the resection of giant pituitary macroadenomas.

METHODS

We describe an operative technique using a side-firing ultrasound probe (Fujifilm/Hitachi) to identify the diaphragma sellae, confirm optic chiasm decompression, identify vascular structures related to tumor invasion, and maximize extent of resection in giant pituitary macroadenomas.

RESULTS

Side-firing IOUS allows for identification of the diaphragma sellae to help prevent intraoperative cerebrospinal fluid leak and maximize extent of resection. Side-firing IOUS also aids in confirmation of decompression of the optic chiasm via identification of a patent chiasmatic cistern. Furthermore, direct identification of the cavernous and supraclinoid internal carotid arteries and arterial branches is achieved when resecting tumors with significant parasellar and suprasellar extension.

CONCLUSIONS

We describe an operative technique in which side-firing IOUS may assist in maximizing extent of resection and protecting vital structures during surgery for giant pituitary adenomas. Use of this technology may be particularly valuable in settings in which intraoperative magnetic resonance imaging is not available.

Validation and implementation of Aperio LV1 remote live view telepathology system for intraoperative frozen section diagnosis

Introduction

Telepathology (TP) allows for remote slide review with performance comparable to traditional light microscopy. Use of TP in the intraoperative setting allows for faster turnaround and greater user convenience by obviating the physical presence of the attending pathologist. We sought to perform a practical validation of an intraoperative TP system using the Leica Aperio LV1 scanner in tandem with Zoom teleconferencing software.

Methods

A validation was performed in accordance with recommendations from CAP/ASCP, using a retrospectively identified sample of surgical pathology cases with a 1 year washout period. Only cases with frozen-final concordance were included. Validators underwent training in the operation of the instrument and conferencing interface, then reviewed the blinded slide set annotated with clinical information. Validator diagnoses were compared to original diagnoses for concordance.

Results

60 slides were chosen for inclusion. 8 validators completed the slide review, each requiring 2 h. The validation was completed in 2 weeks. Overall concordance was 96.4%. Intraobserver concordance was 97.3%. No major technical hurdles were encountered.

Conclusion

Validation of the intraoperative TP system was completed rapidly and with high concordance, comparable to traditional light microscopy. Institutional teleconferencing implementation driven by the COVID pandemic facilitated ease of adoption.

Ultrasound Elastography in Neurosurgery: Current Applications and Future Perspectives

BACKGROUND

Similar to clinical palpation, Ultrasound elastography (USE) helps distinguish between tissues by providing information on their elasticity. While it has been widely explored and has been applied to many body organs, USE has not been studied as extensively for application in neurosurgery. The current systematic review was performed to identify articles related to the use of interoperative USE in neurosurgery.

METHODS

Search included MEDLINE(R) database. Only original peer-reviewed full-text articles were included. No language or publication year restrictions were imposed. Two independent reviewers assessed the search results for relevance. The identified articles were screened by title, abstract, and full-text review.

RESULTS

Seventeen articles were included in the qualitative analysis and 13 articles were related to oncology, epilepsy (n = 3), and spine (n = 1). In oncology, USE was found useful in defining tumor stiffness, aiding surgical planning, detecting residual tumors, discriminating between tumor and brain tissue, and differentiating between different tumors. In epilepsy, USE could improve the detection of epileptogenic foci, thereby enhancing the prospect of complete and safe resection. The application in spinal surgery was limited to demonstrating that a compressed spinal cord is stiffer than the decompressed one.

CONCLUSIONS

USE was found to be a safe, quick, portable, and economic tool that was a useful intraoperative adjunct to provide information corresponding to a variety of neurosurgical diseases, at different stages of surgery. This review describes the current intraoperative neurosurgical applications of USE, the concept of elasticity, and different USE modalities as well as the technical challenges, limitations, and possible future implications.

National Joint Registry recorded untoward intraoperative events during primary total hip arthroplasty: an investigation into the data accuracy, causal mechanisms and attributability

INTRODUCTION

Untoward intraoperative events occurring during total hip arthroplasty are recorded by the National Joint Registry through Minimum Data Set (MDS) forms. This data may be used to assess the safety of implants. The aim of this study is to evaluate the accuracy of the untoward intraoperative events, assess the mechanism and ascertain whether these events were attributable to the implants inserted.

METHODS

A retrospective analysis was undertaken of primary total hip arthroplasties performed between 2005 and 2018 in which an untoward intraoperative event was recorded.

RESULTS

Of 12,802 primary hip replacements, 64 patients (0.5%) had untoward intraoperative events recorded on the MDS form. In 43 of 64 cases, the intraoperative untoward event recorded on the MDS form matched the operation notes. Among these 43 cases, in 30 (69%) patients the intraoperative event could be attributed to the implant recorded. In the remaining 13 (31%) cases, the events recorded could not be attributed to the implant. In six cases, the untoward events were attributed to implants used to manage the events rather than the implants which caused them. In seven cases, the untoward events were related to surgical technique rather than to the implant or instrumentation.

CONCLUSIONS

Our analysis highlights that all untoward intraoperative events recorded on the NJR form are not implant related or attributable to the implant inserted. Provision should be made on the MDS form to clarify whether a particular untoward intraoperative event was related to the implant inserted.

Foundations of Neuropsychology: Collaborative Care in Neurosurgery

The disciplines of neuropsychology and neurosurgery have a history of partnership that has improved prognoses for patients with neurologic diagnoses that once had poor outcomes. This article outlines the evolution of this relationship and describes the current role that clinical neuropsychology has within a department of neurological surgery across the preoperative, intraoperative, and postoperative stages of treatment. Understanding the foundations of collaboration between neuropsychology and neurosurgery contextualizes present challenges and future innovations for advancing excellence along the continuum of care for all neurosurgical patients.

High gamma activity distinguishes frontal cognitive control regions from adjacent cortical networks

Though the lateral frontal cortex is broadly implicated in cognitive control, functional MRI (fMRI) studies suggest fine-grained distinctions within this region. To examine this question electrophysiologically, we placed electrodes on the lateral frontal cortex in patients undergoing awake craniotomy for tumor resection. Patients performed verbal tasks with a manipulation of attentional switching, a canonical control demand. Power in the high gamma range (70-250 Hz) distinguished electrodes based on their location within a high-resolution fMRI network parcellation of the frontal lobe. Electrodes within the canonical fronto-parietal control network showed increased power in the switching condition, a result absent in electrodes within default mode, language and somato-motor networks. High gamma results contrasted with spatially distributed power decreases in the beta range (12-30 Hz). These results confirm the importance of fine-scale functional distinctions within the human frontal lobe, and pave the way for increased precision of functional mapping in tumor surgeries.

A surgeon's framework for the unplanned intraoperative consultation

PURPOSE

Surgeons will likely be called to assist with or offer advice regarding an unanticipated intraoperative event or finding many times during their careers. Yet, there is no practical framework of how to respond to these consults nor is there any formal training in this area. The review of the limited literature and expert senior opinions can help explain the ethical components involved but does not address some of the practical aspects that the consulting surgeon may need to confront when responding to an unplanned intraoperative consultation.

METHODS

We reviewed the existing surgical literature on intraoperative consultation across surgical disciplines and interpreted it in light of our own experiences and the advice of senior surgical colleagues.

RESULTS

We present a framework for the minimum professional expectations of a surgeon responding to an intraoperative consultation.

CONCLUSION

In this manuscript, we present a selected review of the available literature on the topic, establish some of the guiding ethical principles, and offer an actionable and detailed framework that can support trainees and practicing surgeons dealing with these increasingly common and stressful unplanned circumstances.

Vascular surgery is the most commonly consulted specialty for emergent operative trauma

OBJECTIVE

Despite an increasing rate of intraoperative consultation of vascular surgery (VS) for trauma patients, VS is not one of the subspecialties required for American College of Surgeons level I trauma center verification. We sought to assess the rates and patterns of emergent operative VS consultation compared with other surgical subspecialties in the trauma setting.

METHODS

A retrospective analysis was performed on all patients who presented with traumatic injuries requiring emergent surgical operations (<3 hours after presentation) from 2015 to 2019 at a level I trauma center. Patient demographics, injury characteristics, and data on consulted surgical subspecialties were collected. The primary outcome measured was the rate of intraoperative consultation to VS and other subspecialties (OS).

RESULTS

A total of 2265 patients were identified, with 221 emergent intraoperative consults to VS and 507 consults to OS. After VS (9.8%), the most common subspecialties consulted were orthopedics (9.2%) and urology (5%). Overall, VS was more likely to be consulted in immediate trauma operations (<1 hour after presentation) (65.6% vs 38.1%, P < .0001), penetrating injuries (73.3% vs 47.9%, P < .0001), and at night (60.6% vs 51.9%, P = .02) compared with OS. Time from admission to operation was shorter for cases when VS was involved compared with OS (54.1 ± 40.4 vs 80.6 ± 47.9 minutes, P < .0001). In a multivariable logistic regression model, we found that requiring an immediate operation was associated with higher odds of requiring an intraoperative vascular consult (odds ratio = 1.49, 95% confidence interval = 1.12-2.0).

CONCLUSIONS

Vascular surgeons are consulted intraoperatively to assist with emergent trauma at a greater rate compared with specialties that are required for level I trauma center verification. Current American College of Surgeons verification processes and site-specific policies should be re-evaluated to consider VS coverage as a requirement for trauma center verification.

A new approach for clinical translation of infrared spectroscopy: exploitation of the signature of glioblastoma for general brain tumor recognition

PURPOSE

Infrared (IR) spectroscopy has the potential for tumor delineation in neurosurgery. Previous research showed that IR spectra of brain tumors are generally characterized by reduced lipid-related and increased protein-related bands. Therefore, we propose the exploitation of these common spectral changes for brain tumor recognition.

METHODS

Attenuated total reflection IR spectroscopy was performed on fresh specimens of 790 patients within minutes after resection. Using principal component analysis and linear discriminant analysis, a classification model was developed on a subset of glioblastoma (n = 135) and non-neoplastic brain (n = 27) specimens, and then applied to classify the IR spectra of several types of brain tumors.

RESULTS

The model correctly classified 82% (517/628) of specimens as "tumor" or "non-tumor", respectively. While the sensitivity was limited for infiltrative glioma, this approach recognized GBM (86%), other types of primary brain tumors (92%) and brain metastases (92%) with high accuracy and all non-tumor samples were correctly identified.

CONCLUSION

The concept of differentiation of brain tumors from non-tumor brain based on a common spectroscopic tumor signature will accelerate clinical translation of infrared spectroscopy and related technologies. The surgeon could use a single instrument to detect a variety of brain tumor types intraoperatively in future clinical settings. Our data suggests that this would be associated with some risk of missing infiltrative regions or tumors, but not with the risk of removing non-tumor brain.

Methods and Principles of the Intraoperative Neurophysiologic Monitoring in Neurosurgery

Intraoperative neurophysiologic monitoring (IONM) is an innovation introduced in neurosurgery in the past decades. It aims to support and guide the neurosurgeon to obtain the best surgical result possible, preventing the occurrence of neurological deficits. The somatosensory evoked potentials (SSEP) assess the integrity of the sensory pathways monitoring the dorsal column-medial lemniscus pathway during spine and cerebral surgery. Motor evoked potentials (MEPs) provide information on the integrity of the motor pathway monitoring the efferent motor pathways from the motor cortex to the muscle through corticospinal (or corticobulbar) tracts. Free-running EMG is the standard technique to monitor peripheral nerves, roots, or cranial motor nerves during surgery. Intraoperative EMG signals are activated during cranial motor nerves damaging or after an irritative stimulus. The duration, morphology, and persistence of EMG reflects the severity of neural injury. Nerve mapping consists of recording muscle activations given by direct nerve stimulation. This technique makes use of a stimulation probe available to the neurosurgeon which allows administering current directly to the nervous tissue (nerves, roots, etc.). Intraoperative neurophysiological monitoring (IONM) represents the standard of care during many procedures, including spinal, intracranial, and vascular surgeries, where there is a risk of neurological damage. Close communication and collaboration between the surgical team, neurophysiologist, and anesthesiologist is mandatory to obtain high-quality neuromonitoring, thus preventing neurologic injuries and gaining the best surgical "safe" results.

[The perioperative role of high-flow cannula oxygen (HFNO)]

High-flow nasal cannula oxygen (HFNO) is commonly used during the perioperative period. Its numerous physiological benefits, satisfactory tolerance and ease of use have led to its widespread application in intensive care and post-anesthesia care units. HFNO is also used in the operating theater in multiple indications: as oxygen supplementation (associated with pressurization) prior to orotracheal intubation; in digestive and bronchial endoscopies, especially in patients at risk of hypoxemia; and in intraoperative surgery requiring spontaneous ventilation (ENT, thoracic surgery…). During the postoperative period, HFNO can be used in a curative strategy for respiratory failure or in a prophylactic strategy to prevent reintubation. In a curative approach, HFNO seems of interest following cardiac or thoracic surgery but has not been evaluated in respiratory failure subsequent to abdominal surgery, in which case noninvasive ventilation remains the gold standard. The risk of respiratory complications depends on type of surgery and on patient comorbidities. As prophylaxis, HFNO is currently preferred to conventional oxygen therapy after cardiac or thoracic surgery, especially in patients at high risk of respiratory complications. For the clinician, it is important to acknowledge the limits of HFNO and to closely monitor patients receiving HFNO, the objective being to avoid delays in intubation that could lead to increased mortality.

MRI-based and robot-assisted stereotactic biopsy with intraoperative CT imaging

BACKGROUND

As a pioneer center in the field of stereotaxy, Sainte-Anne school has always advocated the use of intraoperative imaging for stereotactic procedures to optimize both safety and accuracy. With the advent of intraoperative mobile CT unit, the robot-assisted stereotactic biopsy procedure has been recently updated.

METHOD

Herein, we aim at describing our new surgical procedure that combines robotic assistance (NeuroMate, Renishaw) and intraoperative cone beam CT imaging (O-Arm, Medtronic).

CONCLUSION

Intraoperative imaging with the O-Arm was efficiently incorporated into the workflow. This new equipment leads to optimizing operative time and an easier realization of intraoperative imaging.

The role of the anterior insular cortex in self-monitoring: A novel study protocol with electrical stimulation mapping and functional magnetic resonance imaging

Becoming aware of one's own states is a fundamental aspect for self-monitoring, allowing us to adjust our beliefs of the world to the changing context. Previous evidence points out to the key role of the anterior insular cortex (aIC) in evaluating the consequences of our own actions, especially whenever an error has occurred. In the present study, we propose a new multimodal protocol combining electrical stimulation mapping (ESM) and functional magnetic resonance imaging (fMRI) to explore the functional role of the aIC for self-monitoring in patients undergoing awake brain surgery. Our results using a modified version of the Stroop task tackling metacognitive abilities revealed new direct evidence of the involvement of the aIC in monitoring our performance, showing increased difficulties in detecting action-outcome mismatches when stimulating a cortical site located at the most posterior part of the aIC as well as significant BOLD activations at this region during outcome incongruences for self-made actions. Based on these preliminary results, we highlight the importance of assessing the aIC's functioning during tumor resection involving this region to evaluate metacognitive awareness of the self in patients undergoing awake brain surgery. In a similar vein, a better understanding of the aIC's role during self-monitoring may help shed light on action/outcome processing abnormalities reported in several neuropsychiatric disorders such as schizophrenia, anosognosia for hemiplegia or major depression.