Safety of Same-Day Discharge after Bariatric Surgery: Retrospective 6-Year North American Analysis

BACKGROUND

With increasing implementation of Enhanced Recovery After Surgery protocols and rising demand for inpatient hospital beds accentuated by COVID-19, there has been interest in same-day discharge (SDD) for bariatric surgery. The aim of this study was to determine the national trends, safety profile, and risk factors for complications of SDD for minimally invasive bariatric surgery.

STUDY DESIGN

We analyzed the MBSAQIP database from 2016 to 2021 to characterize trends in SDD for minimally invasive bariatric operation. Multivariate logistic regression was performed on preoperative patient characteristics predictive of increased complications associated with SDD. A comparative analysis of postoperative outcomes within 30 days was performed for SDD and admission after 1:1 nearest neighbor propensity score matching for patient demographics and preoperative comorbidities.

RESULTS

SDD increased from 2.4% in 2016 to 7.4% in 2021. Major preoperative factors associated with increased complications for SDD included Black race, history of MI, renal insufficiency, deep vein thrombosis, and smoking. SDD for Roux-en-Y gastric bypass had 72% increased risk of postoperative complications compared with sleeve gastrectomy. The overall major complications were lower in SDD cohort vs admission cohort (odds ratio [OR] 0.62, p < 0.01). However, there was a significant increase in deaths within 30 days (OR 2.11, p = 0.01), cardiac arrest (OR 2.73; p < 0.01), and dehydration requiring treatment (OR 1.33; p < 0.01) in SDD cohort compared with admission cohort.

CONCLUSIONS

Nationally, there has been a rise in SDD for bariatric operation from 2016 to 2021. Matched analysis demonstrates that SDD is associated with a significantly higher mortality rate. Additionally, the risk of complications with SDD is higher for RYGB compared with sleeve gastrectomy. Therefore, further studies are required to appropriately select patients for whom bariatric surgery can be safely performed as an outpatient.

Accuracy of Conflicts in Interest in General Surgical Journals

OBJECTIVE

To evaluate the accuracy of self-reported conflicts of interest (COIs) for articles published in prominent minimally invasive and general surgical journals.

BACKGROUND

Accurate reporting of industry relationships and COIs is crucial for unbiased assessment of a particular study. Despite the enactment of COI laws, such as the Physician Payments Sunshine Act in 2010, prior work suggests that 40-70% of self-reported COIs have discrepancies.

METHODS

We utilized three public databases -- Open Payments (USA), Disclosure UK, and Disclosure Australia -- to assess the accuracy of COI disclosures among authors of 918 published articles from these respective countries. Seven journals were utilized to review the COIs for authors of manuscripts published in 2022 - JAMA Surgery, Annals of Surgery, British Journal of Surgery (BJS), Journal of American College of Surgeons (JACS), Surgical Endoscopy, Obesity Surgery, and Surgery for Obesity and Related Diseases (SOARD).

RESULTS

Among the analyzed 6206 authors, 5675 belonged to countries of interest: USA (4282), UK (718), and Australia (213). Of these, 774 authors (12.5%) self-reported a conflict of interest in their papers. Overall, only 4055 researchers (69.1%) reported COIs accurately. Authors from the US had the lowest accuracy of reporting COI at 69% as opposed to UK (93%) and Australia (96%). Inaccurate COI reporting was most common in corresponding/senior authors (39%) and least common amongst first authors (18%). Most payments in excess of $50,000 made to authors by an industry sponsor were not disclosed appropriately.

CONCLUSIONS

Our study shows that inaccuracy of self-reported COIs in general surgery journals remains high at 31%. While our findings should encourage authors to overreport any possible COI, journals should consider verifying the authors' COI to facilitate more accurate reporting.

Open preperitoneal inguinal hernia repair has superior 1-year patient-reported outcomes compared to Shouldice non-mesh repair

INTRODUCTION

The Shouldice method for inguinal hernia repair remains the gold standard for prosthesis-free repairs. Nonetheless, international guidelines have favored posterior mesh reinforcement as the standard of care for inguinal hernia repair due to lower risk of recurrence and chronic pain, avoidance of general anesthesia, and favorable biomechanical properties. Recent publications have shown the benefits of an open approach to posterior repairs. Herein, we use the Abdominal Core Health Quality Collaborative (ACHQC) registry to compare patient-reported outcomes after a Shouldice no-mesh repair versus open preperitoneal (OPP) mesh repair.

METHODS

We performed a propensity score matched analysis to compare patient-reported quality of life (QoL) and peri/postoperative outcomes after a Shouldice repair versus OPP. Data from 2012 to 2022 were obtained from the ACHQC, and 1:1 optimal matching was performed. EuraHS scores were used to estimate QoL, and further analysis on the EuraHS domains of pain, aesthetics, and activity restriction were performed between the two cohorts.

RESULTS

Matching resulted in 257 participants in each, Shouldice and OPP cohorts. OPP was associated with a better QoL score compared to Shouldice at 30 days after surgery (Median (IQR) 7.75 (2.0-17.0) vs 13.0 (4.0-26.1); OR 0.559 [0.37, 0.84]; p = 0.003). This difference persisted at 6 months and 1 year postoperatively (OR 0.447 [0.26, 0.75] and 0.492 [0.26, 0.93], respectively). We did not observe any significant differences in hernia recurrence risk at 1-year, or rates of 30-day SSOs/SSIs, postoperative bleeding, peripheral nerve injury, DVTs, or UTIs.

CONCLUSION

Our data suggest that OPP is associated with significantly better patient-reported QoL, in the first month after surgery and up to 1 year postoperatively, especially with respect to lesser pain, when compared to the Shouldice repair. In specialized inguinal hernia practices, open posterior mesh repairs may lead to better outcomes than non-mesh repairs. We encourage more training in both repairs to facilitate larger prospective studies and evaluation of the generalizability of these results to all surgeons performing IHR.

Concomitant use of monoamine oxidase inhibitor and tyrosine in parenteral nutrition

Monoamine oxidase inhibitors (MAOIs) prevent the breakdown of tyramine in the body, and can cause a sudden increase in blood pressure with significant tyramine build up. This phenomenon, when it occurs, is known as tyramine pressor response. It is unknown if tyrosine administered in parenteral nutrition (PN) leads to tyramine build-up with concomitant use of MAOIs. It is also unknown if PN patients who are taking MAOI are at risk for the tyramine pressor response. This is a theoretical possibility as tyrosine endogenously undergoes decarboxylation to produce tyramine. We describe our experience with a 67-year-old woman with severe depression who was on the MAOI, transdermal selegiline. Her clinical course was complicated by an inability to take adequate per oral (PO) intake and she met criteria for unspecified severe protein-calorie-malnutrition in the context of social or environmental circumstances. Therefore, she required PN initiation. PlenamineTM (B. Braun, Bethlehem, PA, USA) was used as the amino acid source in the PN, which contains 39 mg of tyrosine per 100 ml of solution. The patient was monitored closely for any signs of hypertensive crisis while on PN and selegiline. She safely tolerated the combined therapy without any side effects. This is the first documented report of co-administration of PN containing tyrosine along with a MAOI. Our findings suggest that the dose of selegiline used in this patient can be co-administered safely in the setting of PN. However, further study is needed to verify our findings beyond this one patient. In conclusion, we recommend initiating PN and increasing it to goal in patients taking MAOIs, gradually, while monitoring for hypertensive crisis given the theoretical possibility of the tyramine pressor response.

Expanding Access to Immediate Lymphatic Reconstruction Through an Axillary Surgery Referral Program: A 6-Year Single-Center Experience

BACKGROUND

Recent advances in breast cancer have progressed toward less aggressive axillary surgery. However, axillary lymph node dissection (ALND) remains necessary in specific cases and can increase the risk of lymphedema. Performing ALND with immediate lymphatic reconstruction (ILR) can help lower this risk. This report outlines the implementation of an Axillary Surgery Referral Program (ASRP) to broaden access to ILR, providing insights for institutions considering similar initiatives.

METHODS

A retrospective study analyzed patients referred to the ASRP at Beth Israel Deaconess Medical Center (BIDMC) between 6 January 2017 and 10 December 2022. Patients were identified from a prospective registry, with data subsequently extracted from electronic medical records. This analysis specifically centered on patients referred from external institutions to undergo ALND with ILR.

RESULTS

The program received referrals for 131 patients from institutions across five different states. Annual referrals steadily increased over time. The primary indication for referral was residual axillary disease after neoadjuvant chemotherapy (41.2%). Among the referrals, 20 patients (15.3%) no longer required ALND due to axillary pathologic complete response to neoadjuvant therapy. Care coordination played a crucial role in streamlining the patient care process for both efficiency and effectiveness.

CONCLUSION

The ASRP expands access to ILR for patients with breast cancer, the majority referred for surgical management of residual disease after chemotherapy. The program provides a model for health care institutions aiming to establish similar specialized referral services. Continued program evaluation will be instrumental in refining axillary surgery referral practices and ensuring optimal patient care.

National trends in utilization and safety of gastric bypass, sleeve gastrectomy and conversion surgery in patients with GERD

BACKGROUND

While some studies have reported improvement in gastro-esophageal reflux disease (GERD) symptoms after sleeve gastrectomy (SG), others have reported higher incidence of de-novo GERD, worsening of prior GERD symptoms and erosive esophagitis post SG. Furthermore, GERD unresponsive to medical management is one of the most common indications for conversion of SG to Roux-en-Y gastric bypass (RYGB). Real-world data on safety of primary SG, primary RYGB and SG to RYGB conversion for obese patients with GERD would be helpful for informing surgeons and patient procedure selection. We sought to evaluate the trends in utilization and safety of primary RYGB and primary SG for patients with GERD requiring medications, and compare the peri-operative outcomes between primary RYGB and conversion surgery from SG to RYGB for GERD using the MBSAQIP database.

METHODS

A comparative analysis of post-operative outcomes within 30 days was performed for primary RYGB and primary SG after 1:1 nearest neighbor propensity score matching for patient demographics and preoperative comorbidities using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) registry from 2015 to 2021. This was followed by comparison of peri-operative outcomes between conversion surgery from SG to RYGB for GERD and primary RYGB using MBSAQIP 2020-2021 data.

RESULTS

Utilization of primary RYGB increased from 38% in 2015 to 45% in 2021, while primary SG decreased from 62% in 2015 to 55% in 2021 for bariatric patients with GERD. Post-operative outcomes including reoperation, reintervention, readmission, major complications, and death within 30 days were significantly higher for patients undergoing primary RYGB compared to primary SG. Increased readmissions and ED visits were seen with conversion surgery. However, there was no difference in rates of reoperation, reintervention, major complications, or death between primary RYGB and SG conversion to RYGB cohorts.

CONCLUSIONS

This data suggests that a strategy of performing a primary SG and subsequent SG-RYGB conversion for those with recalcitrant GERD symptoms is not riskier than a primary RYGB. Thus, it may be reasonable to perform SG in patients who are well informed of the risk of worsening GERD requiring additional surgical interventions. However, the impact of such staged approach (SG followed by conversion to RYGB) on long-term outcomes remains unknown.

Adaptation of HLA testing to characterize the cynomolgus macaque MHC polymorphisms and alloantibody signatures

Nonhuman primates are the closest animal models to humans with respect to genetics and physiology. Consequently, a critical component of immunogenetics research relies on drawing inferences from the cynomolgus macaque to inform human trials. Despite the conserved organization of the Major Histocompatibility Complex (MHC) between cynomolgus macaques and humans, MHC genotyping of cynomolgus macaques is challenging due to high rates of copy number variants, duplications, and rearrangements, particularly at the MHC class I loci. Furthermore, the limited availability of commercial reagents specific to cynomolgus macaques that can be used to characterize anti-MHC class I and class II antibody (Ab) specificities in cynomolgus macaques presents a major bottleneck in translational research. Here we successfully characterized cynomolgus macaque Mafa class I and class II serologic specificities in 86 animals originating from various geographical regions using the complement dependent cytotoxicity (CDC) assay with human HLA class I and class II monoclonal antibody (mAb) typing trays. Further, we successfully induced and characterized anti-Mafa class I and class II alloantibody specificity using HLA single antigen bead assays. We also subsequently tracked the alloAb burden in the animals during treatment with anti-B lymphocyte stimulator (BLyS) treatment. Altogether, these methods can be easily used in translational research to serotype MHC class I and class II specificity in macaques, characterize their alloAb specificity, and evaluate the efficacy of novel therapeutic modalities in depleting circulating alloAbs in these animals.

Procedure Matters in Gender-Associated Outcomes following Metabolic-Bariatric Surgery: Five Year North American Matched Cohort Analysis

PURPOSE

Eighty percent of patients who undergo metabolic-bariatric surgery self-identify as female. It is unclear why there is a disparate use of metabolic-bariatric surgery by men compared to women given the widely accepted safety of weight loss surgical procedures. One possible explanation is that post-operative outcomes of metabolic-bariatric surgery have been shown to be worse for men compared to women in prior studies. The purpose of this study was to characterize the impact of gender on outcomes of metabolic-bariatric surgery using the most recent MBSAQIP data registry from 2017-2021.

MATERIALS AND METHODS

Data entered into the MBSAQIP registry from 2017-2021 for patients who underwent primary metabolic-bariatric surgery procedures was identified. The data was then matched for multiple pre-operative factors and comorbidities, and outcomes were assessed and compared for men and women.

RESULTS

No significant difference was observed in anastomotic leak, wound complications, and bleeding between men and women. However, men were at 0.15% (p < 0.01) higher risk of major complications (encompassing unplanned ICU admission, deep organ space infection, unplanned intubation, bleeding, anastomotic leak, sepsis, pneumonia, myocardial infarction, cardiac arrest, cerebrovascular accident, pulmonary embolism, reoperation, and death) compared to women. While men had higher major complications compared to women for SG, there was no significant difference between the two cohorts for RYGB, BPD and LAGB.

CONCLUSION

While there are some differences in outcomes between male and female patients, the difference is modest. Male gender should not be considered a high-risk factor for all bariatric procedures and cannot explain the difference in utilization of metabolic-bariatric surgery by men compared to women.

Improved patient-reported outcomes after open preperitoneal inguinal hernia repair compared to anterior Lichtenstein repair: 10-year ACHQC analysis

INTRODUCTION

The Lichtenstein repair has been synonymous with "open" inguinal hernia repair (IHR) for 40 years. However, international guidelines have suggested that posterior mesh placement results in advantageous biomechanics and reduced risk of nerve-related chronic pain. Additionally, the use of local anesthetics has been shown to reduce postoperative pain and complication risks. An open transrectus preperitoneal/open preperitoneal (TREPP/OPP) repair combines posterior mesh placement with the use of local anesthetic and as such could be the ideal repair for primary inguinal hernia. Using the Abdominal Core Health Quality Collaborative (ACHQC) registry, we compared open anterior mesh with open posterior mesh repairs.

METHODS

We performed a propensity score matched analysis of patients undergoing open IHR between 2012 and 2022 in the ACHQC. After 1:1 optimal matching, both the TREPP/OPP and Lichtenstein cohorts were balanced with 451 participants in each group. Outcomes included patient-reported quality of life (QoL), hernia recurrence, and postoperative opioid use.

RESULTS

Improvement was seen after TREPP/OPP in EuraHS QoL score at 30 days (OR 0.558 [0.408, 0.761]; p = 0.001), and the difference persisted at 1 year (OR 0.588 [0.346, 0.994]; p = 0.047). Patient-reported opioid use at 30-day follow-up was significantly lower in the TREPP/OPP cohort (OR 0.31 [0.20, 0.48]; p < 0.001). 30-day frequency of surgical-site occurrences was significantly higher in the Lichtenstein repair cohort (OR 0.22 [0.06-0.61]; p = 0.007). There were no statistically significant differences in hernia recurrence risk at 1 year, or rates of postoperative bleeding, peripheral nerve injury, DVTs, or UTIs.

CONCLUSION

Our analysis demonstrates a benefit of posterior mesh placement (TREPP/OPP) over anterior mesh placement (Lichtenstein) in open inguinal hernia repair in patient-reported QoL and reduced opioid use.

Reusable scrub caps are cost-effective and help reduce the climate footprint of surgery

BACKGROUND

As the US healthcare sector contributes to 5-10% of national CO2 emissions, with a substantial contribution from surgical services, a collective effort is important to minimize the climate footprint of surgery. Solid plastic waste generated from single-use items in operating rooms is a major contributor to greenhouse gas emissions. To address this problem, we implemented a pilot study to replace single-use scrub caps with reusable caps.

METHODS

Ninety-two surgical trainees at the Massachusetts General Hospital, Boston, were provided reusable personalized scrub caps. Over 6 months, their use of the reusable cap was compared with corresponding use of disposable single-use caps. We then used the cost of raw materials, fabric and cap manufacturing, transportation, and end-of-life/waste treatment to perform an economic and environmental burden analysis.

RESULTS

After 6 months of reusable scrub cap use, 33 participants (51.6%) reported that due to their use of a reusable scrub cap, their utilization of disposable bouffant or caps had decreased by 76-100%. This was associated with a significant reduction in the use of single-use caps after adjusting for surgical case volume. The carbon footprint of single-use scrub caps was significantly higher than reusable caps during the study period. Reusable scrub cap usage also strongly correlated with substantial reductions in energy consumption and freshwater toxicity.

CONCLUSIONS

Reusable personalized cloth scrub caps are cost-effective and can help reduce surgery's carbon footprint by reducing waste generated from disposable scrub cap use. More programs should consider replacing single-use polypropylene caps with reusable scrub caps for their operating room staff.

Personalized Scrub Caps for Identification of Surgical Trainees

This survey study investigates whether personalized scrub caps for surgical trainees can help decrease role and name misidentification, microaggressions, and miscommunication-related delays in patient care.

Beauty Borne out of Chaos: Molding a Surgical Subspecialty Through the World Wars

The chaos during the Great Wars provided the impetus for the genesis of modern plastic surgery. Collectively, the World Wars caused disfiguring injuries to thousands of American soldiers, which challenged their acceptance into society. The Wars, however, propelled 2 leaders in the field of plastic surgery-Vilray P. Blair and James Barrett Brown. These two American pioneers used their surgical acumen and artistic skills to heal the wounds of the soldiers. During World War I, the wounds of injured soldiers were often poorly managed by inadequately trained surgeons and dentists. Upon return to the United States, these soldiers underwent specialized treatment under Blair's supervision. During World War II, James Barrett Brown, a disciple of Blair, was appointed as a consultant in the war. He spearheaded the establishment of several plastic surgery centers in Europe. Upon his return from the War, he led the plastic surgery service at Valley Forge General Hospital in Phoenixville, PA, where thousands of soldiers were sent after their initial operations in the war zones. Care of war wounds served as an impetus for the development of new techniques in reconstructive and plastic surgery. These techniques included a delayed transfer of long pedicled flaps and split-thickness skin grafts. Through our archival research at the Bernard Becker Medical Library at Washington University in St. Louis, we provide evidence for how reconstructive surgical approaches were advanced during the Great Wars and helped restore some form of normalcy to the lives of the injured soldiers.

Abstract 2042: Graph-based pathway analysis of T cell populations in hepatocellular carcinoma reveals novel metabolic regulators of tumor-infiltration lymphocyte activity

With advances in single cell RNA sequencing (scRNAseq), accurate detection of perturbed pathways between conditions or cell types of interest becomes a critical analytical step. The ability to model alterations in a set of genes corresponding of a biological function is particularly useful when comparing cells between healthy and tumor tissues. Yet, few tools exist to detect changes in the multivariate distribution of genes corresponding to a given pathway. We developed a novel, graph-based statistical framework based on optimal matching for testing differential distribution of biological pathways in scRNAseq. We applied our method to data generated from &gt;4,000 T cells isolated from six individuals with hepatocellular carcinoma (HCC). The T cell populations were purified from three tissue locations: peripheral blood, tumor-infiltrating immune cells (TIICs), and normal tissue adjacent to the tumor. We examined the distribution of gene sets that belong to a particular metabolic pathway across T cell subtypes to address the following questions: (1) Which pathways have a similar distribution across T cell subtypes in a given tissue? (2) Are there pathways that have a stable distribution across T cell subtypes in a normal/healthy tissue, but a perturbed distribution in HCC? (3) For pathways that have a disparate distribution across the T cell subtypes, which subtypes show the most distinct distribution? Of the 86 metabolic pathways compared, 41, 63 and 76 metabolic pathways were indistinguishable across T cell subtypes in the tumor, peripheral blood and adjacent normal tissues, respectively. We observed that most metabolic pathways do not show evidence for dissimilar distribution across cell types, suggesting that T cell subtypes might be more similar than previously appreciated in terms of how they regulate their basic metabolic machinery. Further, for each pair of tissue locations, we computed the overlap in perturbed pathways, and found that the concordance was substantially higher for blood and adjacent normal, than what either of these tissues had with the tumor tissue. Interestingly, five metabolic pathways were differentially distributed across the T cell subtypes in each tissue examined in HCC: glycolysis, purine metabolism, glycosphingolipid biosynthesis, pyruvate metabolism, and glycerophospholipid metabolism. Our model also found that CD4+ regulatory T cells were the strongest contributors, driving the differential distribution of these pathways between T cell subtypes in HCC. Altogether, our approach allows for a systems level characterization of pathway activity across multiple cell types with a variety of applications in single cell pathway analysis in oncology. Our work here also highlights unexpected regulatory mechanisms of regulatory T cells that might play in role in the immunobiology of HCC.

Citation Format: Divyansh Agarwal, Tina Bharani, Somabha Mukherjee. Graph-based pathway analysis of T cell populations in hepatocellular carcinoma reveals novel metabolic regulators of tumor-infiltration lymphocyte activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2042.

BLyS neutralization results in selective anti-HLA alloantibody depletion without successful desensitization

Pre-existing anti-HLA allo-antibodies (allo-Abs) are a major barrier to successful kidney transplantation, resulting in an elevated risk for antibody-mediated rejection (AMR) and eventual graft loss. The cytokine B lymphocyte stimulator (BLyS) promotes B cell maturation and plasma cell survival; consequently, anti-BLyS therapy represents a potential therapeutic opportunity in diminishing pre-existing allo-Abs. Here we report that in our 1-year pilot trial, BLyS neutralization failed to reduce total anti-HLA allo-Ab levels in highly sensitized candidates awaiting kidney transplant in a clinically meaningful way. Additionally, we performed a post hoc analysis using sera from trial candidates which revealed selective depletion of anti-HLA class I and class II Abs in response to belimumab treatment, restricted to certain allele specificities and IgG subclasses. Altogether, we observed that BLyS blockade only results in selective depletion of anti-HLA Abs recognizing a few discrete HLA allele specificities.

Effectiveness of a Short Duration of Neoadjuvant Endocrine Therapy in Patients with HR+ Breast Cancer-An NCDB Analysis (2004-2016)

Background

National medical/surgical organizations have recommended the use of neoadjuvant endocrine therapy (NET) to bridge surgery delay of weeks to months for patients with hormone receptor positive (HR+) breast cancer during the ongoing coronavirus disease 2019 (COVID-19) pandemic. The effects of NET of varying durations on pathologic response are unclear. Using the National Cancer Database (NCDB), we evaluated objective response to short (< 9 weeks), moderate (9–27 weeks), and long (> 27 weeks) duration of NET.

Patients and Methods

The study cohort included female patients diagnosed with nonmetastatic invasive HR+ breast cancer, stratifying by those who received NET versus no NET between 2004 and 2016. Pathologic response was grouped into four categories (complete, downstaged, stable, upstaged) by comparing clinical and pathologic staging data. Objective response to NET included complete, downstaged, and stable pathologic response. Clinical characteristics were compared using χ² and analysis of variance (ANOVA) tests. Multivariable logistic regression was used to determine factors associated with NET use and objective response according to NET duration.

Results

A minority (1.2%) received NET in our cohort. Factors associated with NET use included older age, non-Black patients, more advanced clinical stage, higher comorbidity score, government insurance, and lobular histology. Objective response rate (ORR) was 56.7%, 52.1%, and 49.0% after short, moderate, and long NET duration, respectively.

Conclusion

Short NET duration did not result in an inferior ORR. Future study to evaluate the interaction between surgery delay and NET use on clinical outcome will provide insights into the safety of NET to bridge potential surgery delay in patients with HR+ breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10287-5.

The Utility of Corneal Nerve Fractal Dimension Analysis in Peripheral Neuropathies of Different Etiology

Purpose

Quantification of corneal confocal microscopy (CCM) images has shown a significant reduction in corneal nerve fiber length (CNFL) in a range of peripheral neuropathies. We assessed whether corneal nerve fractal dimension (CNFrD) analysis, a novel metric to quantify the topological complexity of corneal subbasal nerves, can differentiate peripheral neuropathies of different etiology.

Methods

Ninety patients with peripheral neuropathy, including 29 with diabetic peripheral neuropathy (DPN), 34 with chronic inflammatory demyelinating polyneuropathy (CIDP), 13 with chemotherapy-induced peripheral neuropathy (CIPN), 14 with human immunodeficiency virus-associated sensory neuropathy (HIV-SN), and 20 healthy controls (HCs), underwent CCM for estimation of corneal nerve fiber density (CNFD), CNFL, corneal nerve branch density (CNBD), CNFrD, and CNFrD adjusted for CNFL (ACNFrD).

Results

In patients with DPN, CIDP, CIPN, or HIV-SN compared to HCs, CNFD (P = 0.004-0.0001) and CNFL (P = 0.05-0.0001) were significantly lower, with a further significant reduction among subgroups. CNFrD was significantly lower in patients with CIDP compared to HCs and patients with HIV-SN (P = 0.02-0.0009) and in patients with DPN compared to HCs and patients with HIV-SN, CIPN, or CIDP (P = 0.001-0.0001). ACNFrD was lower in patients with CIPN, CIDP, or DPN compared to HCs (P = 0.03-0.0001) and in patients with DPN compared to those with HIV-SN, CIPN, or CIDP (P = 0.01-0.005).

Conclusions

CNFrD can detect a distinct pattern of corneal nerve loss in patients with DPN or CIDP compared to those with CIPN or HIV-SN and controls.

Translational Relevance

Various peripheral neuropathies are characterized by a comparable degree of corneal nerve loss. Assessment of corneal nerve topology by CNFrD could be useful in differentiating neuropathies based on the pattern of loss.