Catheter-Directed Intraarterial Thrombolysis as Part of a Multidisciplinary Management Protocol of Frostbite Injury

Frostbite in the Pediatric Population: A Comprehensive Review and a Prospective Canadian Survey

INTRODUCTION

Frostbite in the pediatric population, where skeletal maturity has not been achieved, can have important repercussions on subsequent growth. Yet, the optimal management of frostbite injuries in children remains vague. This review aims to summarize the current evidence for frostbite management in children and understand Canadian practice trends on this topic.

METHODS

A review using Medline, Scopus, Web of Science, and gray literature was performed to identify relevant literature on the clinical manifestations, diagnostic methods, and treatment options in pediatric frostbite. An online survey was sent to plastic surgeons through the Canadian Society of Plastic Surgeons (CSPS) mailing list to further identify national practices and trends for pediatric frostbite management.

RESULTS

A total of 109 articles were reviewed. No article provided a specific algorithm for pediatric frostbite, with existing recommendations suggesting the use of adult guidelines for treating children. Our survey yielded 9 responses and highlighted the rarity of pediatric frostbite cases, with no responder treating more than 10 cases per year. Most (55.6%) do not use a pediatric-specific treatment algorithm, whereas 30% apply adult guidelines. A conservative approach focusing on rewarming (55.6%), limb elevation (50%), and tetanus status verification (66.7%) was predominant. Imaging and surgical interventions seem to be reserved for severe cases.

CONCLUSIONS

The current literature for pediatric frostbite management lacks specificity. Canadian practices vary, with a trend toward a conservative approach. The limited evidence and rarity of experience highlight the need for further research, ideally in a collaborative multicentric manner, to create a consensus for pediatric frostbite care.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2024 Update

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2019.

American Burn Association Clinical Practice Guidelines on the Treatment of Severe Frostbite

This Clinical Practice Guideline addresses severe frostbite treatment. We defined severe frostbite as atmospheric cooling that results in a perfusion deficit to the extremities. We limited our review to adults and excluded cold contact or rapid freeze injuries that resulted in isolated devitalized tissue. After developing population, intervention, comparator, outcomes (PICO) questions, a comprehensive literature search was conducted with the help of a professional medical librarian. Available literature was reviewed and systematically evaluated. Recommendations based on the available scientific evidence were formulated through consensus of a multidisciplinary committee. We conditionally recommend the use of rapid rewarming in a 38 to 42°C water bath and the use of thrombolytics for fewer amputations and/or a more distal level of amputation. We conditionally recommend the use of "early" administration of thrombolytics (≤12 hours from rewarming) compared to "later" administration of thrombolytics for fewer amputations and/or a more distal level of amputation. No recommendation could be formed on the use of vascular imaging studies to determine the use of and/or the time to initiate thrombolytic therapy. No recommendation could be formed on the use of intravenous thrombolytics compared to the use of intra-arterial thrombolytics on fewer amputations and/or a more distal level of amputation. No recommendation could be formed on the use of iloprost resulting in fewer amputations and/or more distal levels of amputation. No recommendation could be formed on the use of diagnostic imaging modalities for surgical planning on fewer amputations, a more distal level of amputation, or earlier timing of amputation.

Update on Cold-Induced Injuries

Cold-induced injuries are a major challenge for burn surgeons, leading to significant sequelae for the patients including amputations, long-term disability, and death. Rapid assessment and diagnosis are essential for optimal outcomes. Various therapies have emerged to improve outcomes. Topical, oral, and intravenous agents have shown to minimize the impact of cold-induced injuries. Thrombolytics have shown the greatest promise in improving tissue perfusion outcomes in cold-induced injuries. This article provides an update on the evidence-based assessment and management of cold-induced injuries, as well as reviews outcomes and future directions of this challenging pathology.

Frostbite treatment: a systematic review with meta-analyses

INTRODUCTION

Our objective was to perform a systematic review of the outcomes of various frostbite treatments to determine which treatments are effective. We also planned to perform meta-analyses of the outcomes of individual treatments for which suitable data were available.

MAIN BODY

We performed a systematic review and meta-analyses in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched PubMed, Cochrane Trials, and EMBase to identify primary references from January 1, 1900, to June 18, 2022. After eliminating duplicates, we screened abstracts to identify eligible studies containing information on treatment and outcomes of Grade 2 to 4 frostbite. We performed meta-analyses of groups of articles that provided sufficient data. We registered our review in the prospective registry of systematic reviews PROSPERO (Nr. 293,693). We identified 4,835 potentially relevant studies. We excluded 4,610 studies after abstract screening. We evaluated the full text of the remaining 225 studies, excluding 154. Ultimately, we included 71 articles with 978 cases of frostbite originating from 1 randomized controlled trial, 20 cohort studies and 51 case reports. We found wide variations in classifications of treatments and outcomes. The two meta-analyses we performed both found that patients treated with thrombolytics within 24 h had better outcomes than patients treated with other modalities. The one randomized controlled trial found that the prostacyclin analog iloprost was beneficial in severe frostbite if administered within 48 h.

CONCLUSIONS

Iloprost and thrombolysis may be beneficial for treating frostbite. The effectiveness of other commonly used treatments has not been validated. More prospective data from clinical trials or an international registry may help to inform optimal treatment.

Catheter-Directed Thrombolysis for Acute Digit Ischemia in the Setting of Heterozygous Factor V Leiden Mutation: A Case Report and Review of Literature

CASE

We are reporting the successful treatment of a patient with a heterozygous factor V Leiden mutation who presented with spontaneous thrombotic ischemia of ring and small fingers. Microcatheter-directed administration of thrombolytics at the level of common and proper digital arteries resulted in the salvage of the ring finger to the level of the distal tuft and the entirety of the small finger.

CONCLUSION

Heterozygous factor V Leiden mutation is an extremely unusual etiology for thrombotic digital ischemia. This case report emphasizes the importance of correct diagnosis, timely intervention, and thrombolytic therapy using microcatheters to optimize digital rescue.

Thrombolytic Use in Management of Frostbite Injuries: Eight Year Retrospective Review at a Single Institution

Frostbite injuries are uncommon, understudied, and lack standardized treatment protocols. Although thrombolytics are commonly used, their efficacy remains controversial. Herein, we report the results of a retrospective review of frostbite treatment practices at a single institution. The impact of thrombolytics on outcomes was evaluated. Medical records of frostbite patients admitted between January 2010 and April 2018 were reviewed. Demographics, injury details, treatment, and outcomes were collected. Descriptive statistics were obtained. A case-control analysis comparing patients who received tissue plasminogen activator (tPA) with those who did not was performed. A total of 102 patients were included. The mean age was 43 ± 17.7; 82.4% were male. About 13% of patients were presented with first-degree, 54% with second-degree, 29% with third-degree, and 5% with fourth-degree frostbite. Toes (69%), fingers (53%), and feet (43%) were most commonly affected. Thirteen patients had angiograms. Twelve patients received tPA: three systemic tPA and nine catheter-directed tPA. Overall, 32 patients (31%) required surgery and 27 (26.5%) patients required amputation with an average of 6.5 digits amputated. Digit salvage rate based on angiography was 84.7%. Length of stay (P = .046), number of operations (P = .037), and need for surgery (P = .030) were significantly lower for patients who received thrombolytics. Two patients had bleeding complications but did not require intervention or interruption of therapy. Despite its small sample size, our study suggests benefits from thrombolytic therapy. Prospective, well designed, and multi-institutional studies are warranted to establish evidence-based treatment guidelines for the management of frostbite injuries.

High Cost and Resource Utilization of Frostbite Readmissions in the United States

BACKGROUND

Frostbite is a high morbidity, high-cost injury that can lead to digit or limb necrosis requiring amputation. Our primary aim is to describe the rate of readmission following frostbite injury. Our secondary aims are to describe the overall burden of care, cost, and characteristics of repeat hospitalizations of frostbite-injured people.

METHODS

Hospitalizations following frostbite injury (index and readmissions) were identified in the 2016 and 2017 Nationwide Readmission Database. Multivariable logistic regression was clustered by hospital and additionally adjusted for severe frostbite injury, gender, year, payor group, severity, and comorbidity index. Population estimates were calculated and adjusted for by using survey weight, sampling clusters, and stratum.

RESULTS

In the two-year cohort, 1,065 index hospitalizations resulted in 1,907 total hospitalizations following frostbite injury. Most patients were male (80.3%), lived in metropolitan/urban areas (82.3%), and nearly half were insured with Medicaid (46.4%). Of the 842 readmissions, 53.7% were associated with complications typically associated with frostbite injury. Overall, 29% of frostbite injuries resulted in at least one amputation. The average total cost and total LOS of readmissions was $236,872 and 34.7 days. Drug or alcohol abuse, homelessness, Medicaid insurance, and discharge AMA were independent predictors of unplanned readmission. Factors associated with multiple readmissions include discharge AMA and Medicare Insurance, but not drug or alcohol abuse or homelessness. The population-based estimated unplanned readmission rate following frostbite injury was 35.4% (95% CI 32.2 - 38.6%).

CONCLUSIONS

This is the first study examining readmissions following frostbite injury on a national level. Drug or alcohol abuse, homelessness, Medicaid insurance, and discharge AMA were independent predictors of unplanned readmission, while only AMA discharge and Medicare insurance were associated with multiple readmissions. Supportive resources (community and hospital-based) may reduce unplanned readmissions of frostbite injured patients with those additional risk factors.

Management of severe frostbite with iloprost, alteplase and heparin: a Yukon case series

BACKGROUND

We identified the need to modernize frostbite management in our northern centre and implemented a treatment protocol in 2015. Our aim was to describe the clinical course of patients presenting to the hospital since the implementation of the protocol.

METHODS

This was a retrospective case series from Whitehorse General Hospital, Whitehorse, Yukon Territory, Canada. We reviewed the charts of patients who presented to the hospital with grade 2-4 frostbite and were treated as per our protocol between Feb. 9, 2015, and Feb. 8, 2020. Patients with grade 2-4 frostbite received iloprost; in addition, those with grade 4 frostbite received alteplase and heparin. We determined the number of digits affected and salvaged, and the time from presentation to the emergency department to treatment initiation. We also examined patients' demographic characteristics, predisposing events, frostbite severity and adverse drug reactions.

RESULTS

In 22 patients treated for grade 2-4 frostbite, 142 digits were affected: 59 with grade 2 frostbite, 25 with grade 3 frostbite and 58 with grade 4 frostbite; of the 142, 113 (79.6%) were salvaged. All 29 digits amputated had grade 4 frostbite. The mean time from presentation to iloprost initiation was reduced from 32.9 hours in 2015 to 3.0 hours in 2020. Sports (10 cases [45%]) and alcohol use (6 [27%]) were the most common precipitating events, with alcohol use tending to result in more severe injury (grade 4 in 5 of 6 cases). Adverse reactions with iloprost (e.g., headache) were common but mild. Adverse reactions with alteplase (e.g., bleeding) were less common but of greater clinical significance.

INTERPRETATION

Over the study period, our protocol contributed to improvement in frostbite care at our institution, resulting in a digit salvage rate comparable to other published results. Our 5-year experience shows that advanced medical care of frostbite can be achieved, even at a rural centre.

Research progress in the pathogenic mechanisms and imaging of severe frostbite

PURPOSE

This article reviews the pathological mechanisms and progress of imaging of severe frostbite to assist in the search for targets for clinical diagnosis and treatment of severe frostbite. This review also aims to provide strong evidence for clinical diagnosis and treatment of deep frostbite.

METHODS

The review was based on the summary and analysis of the existing literature, and explored the pathological mechanism of deep frostbite and the advantages and disadvantages of imaging diagnostic methods.

RESULTS

According to the depth of tissue involvement, frostbite is divided into 4 levels. Severe frostbite includes Grade 3 and Grade 4 frostbite. Clinical performance evaluation and imaging diagnostic research have always been the mainstream of severe frostbite diagnosis. Imaging methods focus on vascular patency and tissue vitality. This article introduces angiography, SETCT/CT and MRA, and we summarize the advantages and disadvantages of these imaging methods. We recommend corresponding imaging modalities according to the state of frostbite patients.

CONCLUSIONS

Imaging examination, especially angiography and bone scans, provide useful information for determining the diagnosis and prognosis of severe frostbite. In order to obtain a good clinical prognosis, clinicians should first perform SPECT/CT. MRA does not burden the patient's body, but the balance between cost and benefit must be considered. Angiography provides a good feedback on the changes in blood vessel status before and after treatment, which is helpful for discovering the response of limbs to treatment.

Using Intra-arterial tPA for Severe Frostbite Cases. An Observational Comparative Retrospective Study

Frostbite causes tissue damage through five major mechanisms, out of which two are amenable to treatment. The first-line treatment is rapid rewarming therapy using water at 40°C to 42°C, which addresses the formation of ice crystals in the intra and extra cellular compartments. The second mechanism is progressive tissue ischemia after rewarming and is only accessible to a second-line therapy represented by thrombolysis. This study aimed to determine the efficacy of thrombolysis. This is a single-center retrospective cohort study, where it was aimed to evaluate two groups of patients. A total of 18 patients were included in this study. Mean times between injury to thrombolytic therapy and admission to thrombolytic therapy was 26.04 hours (SD 13.6) and 9.65 hours (SD 9.89), respectively. All patients suffered injuries ranging from second-degree deep to third degree. The rate of patients having complete, partial, and no angiographic responses were 55.6%, 11.1%, and 33.3%, respectively. The main outcome of interest showed that 11 (61.1%) patients in total had amputations at different levels. Results showed that in the intervention group, five (55.6%) of the patients had amputations compared with six (66.7%) from the control group (P = .6) at comparable levels of amputation. The literature supports that the use of intra-arterial tissue plasminogen activator might be beneficial for severe cases of frostbites; however, it lacks of studies of major significance and results are often controversial. Our study has not shown statistically significant results on amputation levels and cannot support the hypothesis of efficacy of thrombolytic therapy.

Frostbite: Current status and advancements in therapeutics

Frostbite is a severe ischemic injury which occurs due to the tissue vascular damage after sub-zero temperature tissue exposure. Deep frostbite can result in necrosis and may need amputation of affected tissue. Though a serious injury, it is not very well understood, and further scientific exploration is needed. This work explores the current understanding of the pathophysiology of frostbite. We reviewed the current status of the diagnostics, the drugs, the therapies and the surgical practices for prevention and management of frostbite. Advances in nanotechnology and drug delivery had improved the therapeutic outcomes significantly. This review also explored the latest advancements and researches done for development of newer therapeutics and diagnostics for frostbite care.

Protocoled thrombolytic therapy for frostbite improves phalangeal salvage rates

Background

Frostbite is a cold injury that has the potential to cause considerable morbidity and long-term disability. Despite the complexity of these patients, diagnostic and treatment practices lack standardization. Thrombolytic therapy has emerged as a promising treatment modality, demonstrating impressive digit salvage rates. We review our experience with thrombolytic therapy for severe upper extremity frostbite.

Methods

Retrospective data on all frostbite patients evaluated at our institution from December 2017 to March 2018 was collected. A subgroup of patients with severe frostbite treated with intra-arterial thrombolytic therapy (IATT) were analysed.

Results

Of the 17 frostbite patients treated at our institution, 14 (82%) were male and the median age was 31 (range: 19–73). Substance misuse was involved in a majority of the cases (58.8%). Five (29.4%) patients with severe frostbite met inclusion criteria for IATT and the remaining patients were treated conservatively. Angiography demonstrated a 74.5% improvement in perfusion after tissue plasminogen activator thrombolysis. When comparing phalanges at risk on initial angiography to phalanges undergoing amputation, the phalangeal salvage rate was 83.3% and the digit salvage rate was 80%. Complications associated with IATT included groin hematoma, pseudoaneurysm and retroperitoneal hematoma.

Conclusions

Thrombolytic therapy has the potential to greatly improve limb salvage and functional recovery after severe frostbite when treated at an institution that can offer comprehensive, protocoled thrombolytic therapy. A multi-center prospective study is warranted to elucidate the optimal treatment strategy in severe frostbite.

Guidelines for Thrombolytic Therapy for Frostbite

The data are insufficient to support standardized treatment of all patients with frostbite with thrombolytic therapy. The following guidelines, however, should be applied to all patients with cyanosis persisting proximal to the distal phalanx (Grade 3 or 4 frostbite injury) and demonstrated loss of perfusion at or proximal to the middle phalanx immediately after rewarming.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2019 Update

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2014.

Thrombolytic Salvage of Threatened Frostbitten Extremities and Digits: A Systematic Review

Frostbite is a cold injury that results in soft tissue loss and can lead to amputation. Vascular thrombosis following injury causes ischemic tissue damage. Despite understanding the pathology, its treatment has remained largely unchanged for over 30 years. Threatened extremities may be salvaged with thrombolytics to restore perfusion. The authors performed a systematic review to determine whether thrombolytic therapy is effective and to identify patients who may benefit from this treatment. The Pubmed, EBSCO, and Google Scholar databases were queried using the key words “thrombolytics,” “frostbite,” “fibrinolytics,” and “tPA.” Studies written after 1990 in English met inclusion criteria. Exclusion criteria were failure to delineate anatomic parts injured, failure to report number of limbs salvaged, animal studies, and non-English language publications. Thrombolytic therapy was defined as administration of tPA, alteplase, urokinase, or streptokinase. Forty-two studies were identified and 17 included. Included were 1 randomized trial, 10 retrospective studies, 2 case series, and 4 case reports. One thousand eight hundred and forty-four limbs and digits in 325 patients were studied and 216 patients treated with thrombolytics and 346 amputations performed. The most common means of thrombolysis was intra-arterial tPA. The most common duration of therapy was 48 hours. Limb salvage rates ranged from 0% to 100% with a weighted average of 78.7%. Thrombolytics are a safe and effective treatment of severe frostbite. They represent the first significant advancement in frostbite treatment by preventing otherwise inevitable amputations warranting both greater utilization and further research to clarify the ideal thrombolytic protocol.

The Use of tPA in the Treatment of Frostbite: A Systematic Review

BACKGROUND

The use of tissue plasminogen activator (tPA) for the treatment of frostbite has been reported and advocated, but its efficacy has not been well established. We conducted a systematic review to guide physicians on the role of tPA in the treatment of frostbite. Our hypothesis was that the use of tPA improves clinical outcomes, as measured by amputation rate.

METHODS

We searched MEDLINE (PubMed) and EMBASE for primary research articles on the use of tPA for the treatment of extremity frostbite. Information related to study design, outcomes, and complications was extracted. A total of 204 citations were screened, and then 35 abstracts and 24 reports were reviewed. Fifteen studies met the standard for final review.

RESULTS

One randomized, prospective study; 3 cohort studies; 8 case series; and 3 case reports were found. A total of 208 patients were treated. Differences in protocols, inclusion criteria, and outcomes measures prevented combining the study results. In all the studies, the authors reported that the use of tPA was or may have been useful in reducing amputation rates or increasing tissue salvage. Complication rates ranged from 0% to 100%, with a combined rate of 13%. The quality of the evidence was low.

CONCLUSIONS

Due to the low scientific quality of the studies, the efficacy of tPA in reducing amputation rates cannot currently be established. Randomized, prospective trials or well-controlled cohort studies are needed to better assess the role of tPA. Consideration should be given to limiting its use to research protocols.

Intra-arterial Thrombolysis for Extremity Frostbite Decreases Digital Amputation Rates and Hospital Length of Stay

PURPOSE

To report outcomes of intra-arterial thrombolysis versus non-thrombolytic management of severe frostbite with respect to digital amputation rates and hospital length of stay (LOS).

MATERIALS AND METHODS

Seventeen patients with severe frostbite were identified from 2000 to 2017. Eight (47%) patients with mean age of 40 years underwent intra-arterial thrombolysis and served as the treatment group. Nine (53%) patients with mean age of 53 years received non-thrombolytic management and served as the control group. 2/8 (25%) treatment and 3/9 (33%) control patients had underlying vascular comorbidities (p = 0.25). Number of digits at risk, duration of thrombolysis, thrombolytic agents used, digits amputated, hospital LOS, and complications were recorded.

RESULTS

Seven upper and nine lower extremities for a total of 80 digits were at risk in the treatment cohort. Eight upper and 12 lower extremities for a total of 100 digits were at risk in the control group. Mean duration of thrombolysis was 26 h. All treatment patients received tissue plasminogen activator in addition to systemic heparin. 4/16 (25%) limbs received intra-arterial alprostadil, 2/16 (13%) received nitroglycerin, and 2/16 (13%) received nicardipine. 12/80 (15%) treatment digits and 77/100 (77%) control digits required amputation (p = 0.003). Average hospital LOS was 14 days in the treatment group and 38 days in the control group (p = 0.011). No major complications occurred in the treatment group; however, 2/9 (22%) patients in the control group required extended hospitalizations secondary to amputation complications.

CONCLUSIONS

Intra-arterial thrombolysis reduces digital amputation rates and hospital LOS in the setting of severe frostbite.