Abscopal downstaging of intermediate stage hepatocellular via combination cryoablation and immunotherapy with complete pathologic response

The abscopal effect is a rare phenomenon characterized by disease regression in distant sites after tumoral locoregional therapy. Locoregional therapy, such as cryoablation, can induce an antitumor immunological response, potentially improving outcomes in cancer patients receiving immunotherapy. This report describes a patient with multifocal hepatocellular carcinoma who progressed through multiple locoregional therapies, was initially unresponsive to immunotherapy, and later achieved rapid and sustained disease regression with a combination cryoablation and immunotherapy. A 5-year sustained complete tumor response successfully bridged to liver transplantation.

Radiation Segmentectomy for the Treatment of Hepatocellular Carcinoma: A Practical Review of Evidence

Radiation segmentectomy is a versatile, safe, and effective ablative therapy for early-stage hepatocellular carcinoma. Advances in radiation segmentectomy patient selection, procedural technique, and dosimetry have positioned this modality as a curative-intent and guideline-supported treatment for patients with solitary HCC. This review describes key radiation segmentectomy concepts and summarizes the existing literary knowledgebase.

A Possible Newly Defined and Treatable Secondary Cause of Early Morning Wake-Up Headaches in an Older Hypermobile Woman: Nutcracker Physiology with Spinal Epidural Venous Congestion

Introduction

Left renal vein compression (nutcracker physiology) with secondary spinal epidural venous congestion is a newly recognized cause of daily persistent headache. Presently, only women with underlying symptomatic hypermobility issues appear to develop headache from this anatomic issue. The hypothesized etiology is an abnormal reset of the patient's cerebrospinal fluid (CSF) pressure to an elevated state. Headaches that occur during sleep can have a varied differential diagnosis, one of which is elevated CSF pressure. We present the case of an older woman who began to develop severe wake-up headaches at midnight. She was found to have left renal vein compression and spinal epidural venous congestion on imaging. After treatment with lumbar vein coil embolization, which alleviated the spinal cord venous congestion, her headaches alleviated.

Case Report

A 61-year-old woman with a history of hypermobile Ehlers-Danlos syndrome began to be awakened with severe head pain at midnight at least several times per week. The headache was a holocranial, pressure sensation, which worsened in the supine position. The headaches were mostly eliminated with acetazolamide. Because of her hypermobility issues and pressure-like headache, she was investigated for underlying nutcracker physiology and spinal epidural venous congestion. This was confirmed using magnetic resonance (MR) angiography and conventional venography, and after lumbar vein coil embolization her wake-up headaches ceased.

Conclusion

The case report suggests a possible new underlying and treatable cause for early morning, wake-up headaches: nutcracker physiology with secondary spinal epidural venous congestion. The case expands on the clinical headache presentation of nutcracker physiology.

A secondary daily persistent headache from onset with underlying nutcracker physiology and spinal epidural venous congestion: case series with lumbar vein embolization as a therapeutic approach

The authors have published on a unique subset of patients whose headaches worsened in the Trendelenburg position and who on time-resolved MR angiography demonstrated left renal vein compression (nutcracker physiology) with retrograde left second lumbar vein (L2LV) flow and regional spinal epidural venous plexus (EVP) congestion. We hypothesized that the spinal EVP congestion subsequently causes a secondary congestion of the cerebral venous system, which then leads to an elevation of CSF pressure above that individuals CSF pressure set point. This results in a daily headache from onset. Thus, eliminating the spinal EVP could conceivably improve or eliminate the manifested headache syndrome. We now present a case series of four patients with long-term follow-up utilizing lumbar vein coil embolization as a new therapeutic approach. In each patient, the MR angiography findings were verified by catheter-based venography. Treatment consisted of endovascular embolization of the second lumbar vein. Four patients have had coil embolization of which three are 1 year or longer from their procedure while one is 10 months posttreatment. All patients were women. Duration of daily headache prior to embolization ranged from 4 to 8 years. Post-embolization: Three patients are either headache free or 90-95% improved with substantial pain free time. There were no procedure-related complications. Our results suggest that embolization of L2LV in a specific patient population with nutcracker physiology may substantially improve head pain issues. This is a minimally invasive outpatient technique with no apparent side effects.

Evaluating the Performance of a Commercially Available AI Algorithm for Automated Detection of Pulmonary Embolism on CECT and CTPA of COVID-19 Patients

Objective

To investigate the performance of a commercially available artificial intelligence (AI) algorithm for detection of pulmonary embolism (PE) on contrast-enhanced CTs in patients hospitalized for COVID-19.

Patients & Methods

Retrospective analysis was performed of all contrast-enhanced chest CTs on patients admitted for COVID-19 between March 2020 and December 2021. Based on the original radiology reports, all PE-positive exams were included (n=527). Using a reversed flow single gate diagnostic accuracy case-control model, a randomly selected cohort of PE-negative exams (n=977) was included. Pulmonary parenchymal disease severity was assessed for all included studies using a semi-quantitative system, the Total Severity Score (TSS). All included CTs were sent for interpretation by the commercially available AI algorithm, Aidoc. Discrepancies between AI and original radiology reports were resolved by three blinded radiologists, who rendered a final determination of indeterminate, positive, or negative.

Results

A total of 78 studies were found to be discrepant, of which 13 (16.6%) were deemed indeterminate by readers and excluded. The sensitivity and specificity of AI was 93.2%; (95% confidence interval [CI] 90.6-95.2%), and 99.6%; (95% CI 98.9-99.9%), respectively. AI's accuracy for all TSS groups (mild, moderate, severe) was high (98.4%, 96.7%, and 97.2%, respectively). AI was more accurate in PE detection on CTPAs vs CECTs (P < .001), with optimal HU of 362 (P=.048).

Conclusion

The AI algorithm demonstrated high sensitivity, specificity, and accuracy for PE on contrast enhanced CTs in COVID-19 patients regardless of parenchymal disease. Accuracy was significantly affected by the mean attenuation of the pulmonary vasculature. How this affects the legitimacy of the binary outcomes reported by AI is not yet known.

Daily persistent headache with nutcracker physiology and spinal epidural venous congestion: Treatment with lumbar vein embolization

Nutcracker phenomenon (NCP) can cause various congestion syndromes secondary to the superior mesenteric artery (SMA) compressing the left renal vein (LRV) resulting in venous reflux. It has recently been suggested that reflux into the lumbar vein (LV) and epidural venous plexus (EVP) may cause headaches in some patients with NCP. This report illustrates an example of a patient with refractory headaches and imaging findings suggestive of NCP that underwent treatment with percutaneous LV embolization. The patient is a 60-year-old female with daily persistent headaches for 5 years that failed numerous headache preventative medications. Time-resolved magnetic resonance angiography demonstrated NCP with reflux and congestion of the LV and EVP. Catheter-based venography confirmed these findings and the patient was treated with percutaneous embolization of the LV. This case report demonstrates the use of LV embolization to prevent EVP reflux and treat daily headaches due to NCP. The patient's headache resolved the next day. She has been headache-free for 5 months post-treatment. These findings support prior data suggesting that NCP can cause retrograde LV flow, EVP congestion, and elevated cerebrospinal fluid pressures leading to daily persistent headaches. Percutaneous embolization of the LV may be a minimally invasive treatment option for refractory headaches in patients with NCP, retrograde LV flow, and EVP congestion.

Promoting Surgical Resection through Future Liver Remnant Hypertrophy

An inadequate future liver remnant (FLR) can preclude curative-intent surgical resection for patients with primary or secondary hepatic malignancies. For patients with normal baseline liver function and without risk factors, an FLR of 20% is needed to maintain postsurgical hepatic function. However, the FLR requirement is higher for patients who are exposed to systemic chemotherapy (FLR, >30%) or have cirrhosis (FLR, >40%). Interventional radiologic and surgical methods to achieve FLR hypertrophy are evolving, including portal vein ligation, portal vein embolization, radiation lobectomy, hepatic venous deprivation, and associating liver partition and portal vein ligation for staged hepatectomy. Each technique offers particular advantages and disadvantages. Knowledge of these procedures can help clinicians to choose the suitable technique for each patient. The authors review the techniques used to develop FLR hypertrophy, focusing on technical considerations, outcomes, and the advantages and disadvantages of each approach. Online supplemental material is available for this article. ^©RSNA, 2022.

Radiation Segmentectomy for the Treatment of Primary Hepatic Malignancies of the Caudate Lobe: A Case Series

PURPOSE

Tumors involving the caudate lobe present a unique therapeutic challenge due to their complex anatomy and the safety and efficacy of locoregional therapy can be variable. The purpose of this study is to analyze the outcomes of radiation segmentectomy for primary caudate lobe tumors.

MATERIALS AND METHODS

Eight patients [5 women and 3 men; median age = 69 y (range 50-79)] that underwent transarterial radioembolization (TARE) using yttrium-90 (Y90) glass microspheres for primary caudate lobe tumors (hepatocellular carcinoma = 6, intrahepatic cholangiocarcinoma = 2) from August 2017 to March 2021 were retrospectively analyzed. Descriptive statistics, treatment parameters, tumor response (using modified response evaluation criteria in solid tumors), adverse events [using common terminology criteria for adverse events (CTCAE)], and survival outcomes were evaluated.

RESULTS

Eight primary caudate lobe tumors with a median size of 2.2 cm [interquartile range (IQR), 1.7-3.3] and Child-Pugh class A liver function underwent TARE of the caudate lobe. The median radiation dose was 596 Gy (IQR 356-1585), median total activity was 0.84 GBq (IQR 0.56-1.31), median specific activity was 473 Bq/sphere (IQR 226-671), and the median number of Y90 microspheres used was 1.4 million (IQR 1.2-3.4). All complications were CTCAE grade 1, and no clinically significant hilar plate complications were observed. In targeted tumors, complete response was seen in all patients.  At a median follow-up period of 16.6 months (IQR 6.6-21.6) 75% (6/8) of patients were alive with no in-field progression.

CONCLUSION

Radiation segmentectomy of primary caudate lobe tumors appears effective and is well tolerated in this limited case series within the described treatment parameters.

LEVEL OF EVIDENCE

Level 4, Case Series.

Role of Radioembolization in Metastatic Neuroendocrine Tumors

The liver is the most common site of metastasis for neuroendocrine tumors originating from the gastrointestinal tract. Neuroendocrine liver metastases (NELMs) portend a worsening clinical course, making local management important. Local treatment options include surgery, thermal ablation, and trans-catheter intra-arterial therapies, such as radioembolization. Radioembolization is generally preferred over other embolotherapies in patients with colonized biliary systems. Current best practice involves personalized treatment planning, optimizing tumor radiation absorbed dose and minimizing radiation to the normal hepatic parenchyma. As part of a multidisciplinary approach, radioembolization is a versatile embolotherapy offering neoadjuvant, palliative, and ablative treatment options for patients with NELMs.

Focal Nodular Hyperplasia and Focal Nodular Hyperplasia-like Lesions

Focal nodular hyperplasia (FNH) is a benign lesion occurring in a background of normal liver. FNH is seen most commonly in young women and can often be accurately diagnosed at imaging, including CT, MRI, or contrast-enhanced US. In the normal liver, FNH frequently must be differentiated from hepatocellular adenoma, which although benign, is managed differently because of the risks of hemorrhage and malignant transformation. When lesions that are histologically identical to FNH occur in a background of abnormal liver, they are termed FNH-like lesions. These lesions can be a source of diagnostic confusion and must be differentiated from malignancies. Radiologists' familiarity with the imaging appearance of FNH-like lesions and knowledge of the conditions that predispose a patient to their formation are critical to minimizing the risks of unnecessary intervention for these lesions, which are rarely symptomatic and carry no risk for malignant transformation. FNH is thought to form secondary to an underlying vascular disturbance, a theory supported by the predilection for formation of FNH-like lesions in patients with a variety of hepatic vascular abnormalities. These include abnormalities of hepatic outflow such as Budd-Chiari syndrome, abnormalities of hepatic inflow such as congenital absence of the portal vein, and hepatic microvascular disturbances, such as those that occur after exposure to certain chemotherapeutic agents. Familiarity with the imaging appearances of these varied conditions and knowledge of their association with formation of FNH-like lesions allow radiologists to identify with confidence these benign lesions that require no intervention. Online supplemental material is available for this article. ^©RSNA, 2022.

Prospective evaluation of lymphatic embolization as part of the treatment in dogs with presumptive idiopathic chylothorax

OBJECTIVE

To describe the embolization technique and short-term clinical outcome in dogs undergoing lymphatic embolization (LE) as part of treatment for presumptive idiopathic chylothorax (IC). Additionally, to document findings in computed tomography lymphangiography (CTLa) following embolization.

STUDY DESIGN

Prospective case series ANIMALS: Eight client-owned dogs.

METHODS

Dogs underwent CTLa followed by thoracic duct ligation (TDL), pericardiectomy (PC) and LE. A mixture of 3:1 lipiodol: n-butyl cyanoacrylate embolic solution was injected through a catheterized mesenteric lymphatic vessel via limited abdominal approach using intraoperative fluoroscopy. CTLa was scheduled for 12 weeks postoperatively, and long-term follow-up was obtained via telephone contact.

RESULTS

LE was technically successful in six of the eight dogs; and clinically successful in five of the six dogs. In the unsuccessful dog, a diagnosis of lymphangiosarcoma was determined, and the owners elected for euthanasia. Five dogs who underwent successful LE underwent CTLa at 12 weeks. Complete resolution of pleural effusion occurred in three dogs and scant pleural effusion in two dogs. A robust lymphatic embolus preventing antegrade continuation of radiocontrast was documented in all five dogs. Five of the six dogs that underwent LE, are alive and clinically normal at 358-960 days postoperatively.

CONCLUSIONS

LE is feasible as part of treatment for dogs with IC. Additionally, a robust lymphatic embolus and lack of radiocontrast flow past the embolus was documented at 12 weeks following surgery.

CLINICAL SIGNIFICANCE

LE has the potential to reduce surgical failure by reducing efferent lymphatic chyle flow, occluding missed lymphatic branches and preventing the development of collateral branches.

Radiation Segmentectomy for the Treatment of Solitary Hepatocellular Carcinoma: Can Outcomes Be Compared to Surgical Resection?

PURPOSE

To investigate outcomes of radiation segmentectomy (RS) versus standard-of-care surgical resection (SR) as a quality endeavor.

MATERIALS AND METHODS

A multisite, retrospective, analysis of treatment-naïve patients who received either RS or SR was performed. Inclusion criteria were solitary HCC ≤8 cm, Eastern Cooperative Oncology Cohort performance status 0-1, and absence of macrovascular invasion or extrahepatic disease. Target tumor and overall progression, time-to-progression (TTP), and overall survival were assessed. Outcomes were censored for liver transplantation.

RESULTS

123 patients were included (RS:57, SR:66). Tumor size, Child-Pugh class, ALBI score, platelet count, and fibrosis stage were significantly different between cohorts (p≤0.01). Grade ≥3 adverse events per Clavien-Dindo classification occurred in 0 RS vs 13(20%) SR patients. Target tumor progression occurred in 3(5%) RS and 5(8%) SR patients, and overall progression in 19(33%) RS and 21(32%) SR patients. Median overall TTP was 21.9 and 29.4 months after RS and SR, respectively (95%CI:15.5-28.2 and 95%CI:18.5-40.3, p=0.03). Overall TTP subgroup analyses showed no difference between cohorts with fibrosis stage 3-4 (p=0.26) and platelets <150x10⁹/L (p=0.29). The overall progression hazard ratio for RS vs SR was not significant per multivariate cox regression analysis (1.16, 95%CI:0.51-2.63, p=0.71). Median overall survival was not reached for either cohort. Propensity scores were calculated but were too dissimilar for matching.

CONCLUSION

Radiation segmentectomy and surgical resection are performed in different patient populations, which limits comparison. Radiation segmentectomy approaches surgical resection outcomes, with a lower incidence of major adverse events, in patients who are not eligible for hepatectomy.

Superior mesenteric venous thrombosis: Endovascular management and outcomes

BACKGROUND

Superior mesenteric venous thrombosis (SMVT) is a rare but fatal condition that is typically treated initially with anticoagulation therapy, and if this fails, with endovascular interventions. However, due to its rarity, there are not many studies that have explored the effectiveness of anticoagulation and endovascular therapies in treating SMVT.

AIM

To evaluate patients diagnosed with SMVT who received endovascular therapy in addition to anticoagulation and report technical and clinical outcomes.

METHODS

A retrospective analysis of the patients who underwent endovascular treatment for SMVT at Mayo Clinic from 2000-2019 was performed. Technical success was defined as angiographic improvement in SMV flow after intervention. Primary patency was defined as the interval from reestablishing mesenteric venous flow until the first repeat thrombotic event or need for additional intervention. Secondary patency was defined as successful restoration of flow after repeat intervention until rethrombosis or last follow-up. The adverse events were reported through Clavien-Dindo classification.

RESULTS

Twenty-four patients were included for analysis. The median age at intervention was 60 years (35-74 years) and 16 (67%) were men. Nineteen patients presented with acute thrombosis (79.2%) and 5 with chronic thrombosis with acute manifestations (20.8%). The most commonly used endovascular modalities were thrombectomy in 12 patients (50.0%) and catheter-directed thrombolysis in 10 patients (41.7%). Technical success was achieved in 18 patients (75%). The 14-d and 30-d primary patency rates were 88.9% and 83.3%, respectively. Adverse events were reported in two patients (8.3%), one marked as grade IIIB, and 1 death marked as grade V. Five-year overall survival rate was 82% (58%-100%).

CONCLUSION

Endovascular intervention with anticoagulation appears to be effective for managing SMVT. This treatment combination may be considered as first-line therapy for SMVT management in select patients.

Radioembolization for the Treatment of Hepatocellular Carcinoma: The Road to Personalized Dosimetry and Ablative Practice

Radioembolization dosimetry for the treatment of hepatocellular carcinoma has evolved alongside our understanding of best practice for this therapy. At the core of advances in dosimetry are personalized and ablative applications of radioembolization, which have generated paradigm shifts in both safety and efficacy. This review provides a summary of fundamental radioembolization dosimetry concepts and narrates how our approach to treating patients has shifted from conventional to tailored and definitive therapy.

Iliocaval reconstruction of chronically thrombosed cylindrical inferior vena cava filters with balloon expandable covered stent-grafts

The use of a Viabahn VBX endoprosthesis (W. L. Gore & Associates, Flagstaff, Ariz) to exclude chronically thrombosed inferior vena cava (IVC) filters refractory to exclusion with self-expanding stents was evaluated. The mean duration of TrapEase IVC (Cordis, Milpitas, Calif) implantation was 7.6 years (range, 2-11 years). Symptoms included leg pain, edema, color changes, and back pain. The mean Villalta score and venous clinical severity score were 17 (range, 13-23) and 13 (range, 11-15), respectively. Indirect ultrasound evidence of stent patency was demonstrated at a mean of 8 months after intervention. The mean Villalta score and venous clinical severity score had decreased by 13 and 10, respectively, at a mean of 9.5 months after intervention. Iliocaval reconstruction with Viabahn VBX balloon expandable stent-graft exclusion of chronically thrombosed TrapEase IVC filters is safe, with favorable short-term results.

Biochemical Safety of Ablative Yttrium-90 Radioembolization for Hepatocellular Carcinoma as a Function of Percent Liver Treated

Purpose

Transarterial radioembolization can serve as an ablative therapy for early-stage hepatocellular carcinoma (HCC). Given the volumetric variability of liver segments, this study aimed to characterize the safety of ablative radioembolization by determining percent liver treated (%LT) thresholds associated with biochemical toxicity.

Patients and Methods

Patients with HCC receiving a single ablative radioembolization treatment using glass microspheres from 2017 through 2020 were reviewed. %LT was calculated as treatment angiosome volume divided by whole liver volume. Biochemical toxicities were defined as increases in Albumin-Bilirubin (ALBI) grade or Child-Pugh (CP) class compared to baseline and albumin or bilirubin adverse events (AEs) per the Common Terminology Criteria for Adverse Events. Receiver operating characteristic curves and multivariate logistic regression analyses were performed to assess the impact of %LT on toxicities.

Results

Of 141 patients analyzed, 53% (n=75) were ALBI 1, 45% (n=64) ALBI 2, 79% (n=111) CP-A, and 21% (n=30) CP-B. A %LT ≥14.5% was associated with grade/class increases in ALBI 2 (p≤0.01) and CP-B patients (p=0.026). In multivariate analysis, a %LT ≥14.5% was an independent predictor of increases in the ALBI 2 and CP-B groups (p<0.01). No significant %LT threshold was found for ALBI 1 and CP-A patients. No grade 3/4 albumin or bilirubin AEs were reported, while grade 2 AEs were related to an initial whole liver volume <1.3 L (p≤0.01).

Conclusion

Patients with ALBI 2 and CP-B liver function are less likely to have an increase in their respective grade/class when treating <14.5% of the liver using glass microspheres. ALBI 1 and CP-A patients showed no definitive %LT threshold for biochemical toxicity within the range of this study.

Natural History of Incidental Enhancing Nodules on Cone-Beam Computed Tomography during Transarterial Therapy of Hepatocellular Carcinoma

PURPOSE

To evaluate the natural history of incidental enhancing nodules (IENs) on contrast-enhanced cone-beam computed tomography (CT) during transarterial treatment of hepatocellular carcinoma (HCC).

MATERIAL AND METHODS

A single-center retrospective analysis of 100 patients with HCC who underwent contrast-enhanced cone-beam CT prior to transarterial treatment from August 2015 to June 2019 was performed. Inclusion criteria were patients with segmental distribution sublobar HCC, contrast-enhanced cone-beam CT of the target lesion and nontarget liver parenchyma, and follow-up cross-sectional imaging. Patients with IENs ≥3 mm that did not meet imaging criteria for HCC were analyzed. Exclusion criteria included biphenotypic tumors and IEN present inside the treated area of the liver.

RESULTS

Fifty-six patients demonstrated 154 IENs on contrast-enhanced cone-beam CT, of which 13 IENs (8.5%) progressed to HCC. The mean primary tumor size was 29 mm (range: 10.2-189 mm). Ten patients had ≥4 IENs, and 46 patients had 1-3 IENs. The mean IEN size was 6.8 mm (range: 3.0-16.3 mm). The median follow-up interval after contrast-enhanced cone-beam CT was 282 days (interquartile range: 143-522). Increased alpha-fetoprotein before treatment (≥15.5 ng/mL, P = .035), having ≥4 IENs (P = .020), and hepatitis C virus (P = .015) were significantly correlated with IEN progression to HCC. No statistically significant differences were identified in baseline neutrophil-to-lymphocyte ratio, targeted HCC characteristics (size, macrovascular invasion, infiltrative pattern, enhancement pattern, and satellite lesions), and IEN size between those with IEN progression to HCC and those without.

CONCLUSIONS

Most IENs of ≥3 mm on contrast-enhanced cone-beam CT in patients with segmental distribution sublobar HCC do not progress to HCC. Patients with segmental distribution sublobar HCC with ≥4 IENs, alpha-fetoprotein elevation (≥15.5 ng/mL), or hepatitis C virus have an increased risk of IEN progression to HCC.

Incidence of acute pulmonary embolism among patients hospitalized with COVID-19: a systematic review and meta-analysis

Background: Coronavirus disease 2019 (COVID-19) is a global pandemic, which is associated with venous thromboembolism and pulmonary embolism (PE). This study aimed to estimate the pooled incidence of PE among patients hospitalized with COVID-19 within the published literature. Methods: This systematic review and meta-analysis was performed according to PRISMA guidelines. An electronic search using MEDLINE /PubMed, ScienceDirect, Cochrane, and OpenGray databases was conducted May 19th, 2020. Eligible studies included sufficient data to calculate the incidence of PE diagnosed during hospitalization in patients with COVID-19. Case reports were excluded. Quality was assessed using the Newcastle-Ottawa scale (observational cohort and case-control), AXIS tool (cross-sectional), and quality assessment tool (case series). Demographics and PE incidence data were extracted from the included studies and analyzed with R language. The pooled incidence of PE in patients hospitalized with COVID-19 was calculated. Results: The database search identified 128 records. Ten observational studies were eligible and were included in the meta-analysis with a total of 1722 patients (mean age= 63.36). .The incidence of PE was noted to be higher in males. The D-dimer levels were specified between PE group and non-PE group in only three studies, while the remaining either reported it improperly or had missing data.The pooled PE incidence in patients hospitalized with COVID-19 was 17% (95% CI: 0.1-0.26). There was a high degree of study heterogeneity (I2 = 94%, p<0.01). Conclusion: The pooled PE incidence in patients hospitalized with COVID-19 is 17%. This increased incidence is greater than that previously reported in the general population of non-COVID-19. Attention and further investigation of this risk is warranted.

Transportal Technetium-99m Labeled Macroaggregated Albumin Scintigraphy to Quantify Occult Intrahepatic Microvascular Portosystemic Shunting

Nodular regenerative hyperplasia (NRH) of the liver may lead to noncirrhotic portal hypertension with subsequent development of portosystemic shunts. While extrahepatic and macrovascular shunts are readily visualized with imaging or endoscopy, there is no standard technique to detect intrahepatic microvascular portosystemic shunting and quantitatively assess shunt burden. We present a case of a 53-year-old female with suspected NRH and hepatopulmonary syndrome with inconclusive liver biopsies and absent portosystemic shunts per abdominal imaging. A percutaneous transportal infusion of Technetium-99m labeled macroaggregated albumin (99mTc-MAA) successfully identified intrahepatic microvascular portosystemic shunting and quantified a lung shunt fraction of more than 30%. NRH was subsequently confirmed with a surgical wedge biopsy and the patient was successfuly treated with a liver transplant. Transportal 99mTc-MAA could be used to both identify and quantify otherwise occult microvascular portosystemic shunts in patients with clinical sequelae of portal hypertension.

Percutaneous direct pancreatic duct intervention in management of pancreatic fistulas: a primary treatment or temporizing therapy to prepare for elective surgery

BACKGROUND

This study evaluates preliminary results of image-guided percutaneous direct pancreatic duct intervention in the management of pancreatic fistula after surgery or pancreatitis when initially ineligible for surgical or endoscopic therapy.

METHODS

Between 2001 and 2018 the medical records of all patients that underwent percutaneous pancreatic duct intervention for radiographically confirmed pancreatic fistula initially ineligible for surgical or endoscopic repair were reviewed for demographics, clinical history, procedure details, adverse events, procedure related imaging and laboratory results, ability to directly catheterized the main pancreatic duct, and whether desired clinical objectives were met.

RESULTS

In 10 of 11patients (6 male and 5 female with mean age 60.5, range 39-89) percutaneous pancreatic duct cannulation was possible. The 10 duct interventions included direct ductal suction drainage in 7, percutaneous duct closure in 3 and stent placement in 1. Pancreatic fistulas closed in 7 of 10, 2 were temporized until elective surgery, and 1 palliated until death from malignancy. The single patient with failed duct cannulation resolved the fistula with prolonged catheter drainage of the peri-pancreatic cavity. There were no major adverse events related to intervention.

CONCLUSION

In patients with pancreatic fistulas initially ineligible for endoscopic therapy or elective surgery, direct percutaneous pancreatic duct interventions are possible, can achieve improvement without major morbidity or mortality, and can improve and maintain the medical condition of patients in preparation for definitive surgery.

Transarterial Yttrium-90 Radioembolization of Hepatocellular Carcinoma Perfused by the Cystic Artery: Multi-institutional Feasibility Study

PURPOSE

To assess the safety and efficacy of transarterial yttrium-90 radioembolization via the cystic artery for patients with hepatocellular carcinoma (HCC) adjacent to the gallbladder with cystic artery supply.

MATERIALS AND METHODS

This retrospective study included 17 patients treated at 4 institutions. Patients with HCC perfused by the cystic artery who received ablative-dose radioembolization were included. Median tumor size was 3.8 cm (range, 2.0-8.8 cm). Fourteen patients (82%) had Child-Pugh class A cirrhosis and 3 (18%) had class B cirrhosis. Adverse events, tumor response, and time to progression were analyzed.

RESULTS

Median dose to the tissue perfused by the cystic artery was 340 Gy (range, 200-720 Gy). There were no occurrences of acute cholecystitis warranting invasive intervention. Four patients (24%) experienced transient right upper quadrant pain, with symptom resolution within 3 mo. Six patients (35%) exhibited gallbladder wall edema on follow-up imaging. Two (12%) and 0 grade 3/4 increases in alkaline phosphatase and bilirubin were observed, respectively. Follow-up imaging demonstrated complete response in 13 target tumors (76%) and partial response in 4 (24%). There were no cases of target tumor progression during a median follow-up of 9 mo (range, 3-72 mo).

CONCLUSIONS

Direct infusion of 90Y microspheres via the cystic artery appears to have an acceptable safety profile, without resulting in acute cholecystitis warranting invasive intervention. In selected patients with HCC in whom other treatments may be contraindicated and the tumor is supplied via the cystic artery, treatment with selective ablative radioembolization can be considered.

Feasibility and efficacy of ultrasonographic and laparoscopic guidance for microwave ablation of clinically normal canine ovaries

OBJECTIVE

To determine the optimal energy profile for and to assess the feasibility and efficacy of ultrasonographic and laparoscopic guidance for microwave ablation (MWA) of clinically normal canine ovaries.

SAMPLE

44 extirpated ovaries from 22 healthy dogs.

PROCEDURES

In the first of 2 trials, 13 dogs underwent oophorectomy by routine laparotomy. Extirpated ovaries underwent MWA at 45 W for 60 (n = 11) or 90 (12) seconds; 3 ovaries did not undergo MWA and served as histologic controls. Ovaries were histologically evaluated for cell viability. Ovaries without viable cells were categorized as completely ablated. Histologic results were used to identify the optimal MWA protocol for use in the subsequent trial. In the second trial, the ovaries of 9 dogs underwent MWA at 45 W for 90 seconds in situ. Ultrasonographic guidance for MWA was deemed unfeasible after evaluation of 1 ovary. The remaining 17 ovaries underwent MWA with laparoscopic guidance, after which routine laparoscopic oophorectomy was performed. Completeness of ablation was histologically assessed for all ovaries.

RESULTS

2 ovaries were excluded from the trial 1 analysis because of equivocal cell viability. Six of 11 ovaries and 10 of 10 ovaries that underwent MWA for 60 and 90 seconds, respectively, were completely ablated. In trial 2, laparoscopic-guided MWA resulted in complete ablation for 12 of 17 ovaries. Dissection of the ovarian bursa for MWA probe placement facilitated complete ablation.

CONCLUSIONS AND CLINICAL RELEVANCE

Laparoscopic-guided MWA at 45 W for 90 seconds was feasible, safe, and effective for complete ablation of clinically normal ovaries in dogs.

Mapping angiography and transarterial technetium macroaggregated albumin particle simulation of recurrent atypical intracranial meningioma: feasibility for potential vascular brachytherapy

Atypical meningioma (AM) (WHO-II) has a recurrence rate of 28% after gross total resection (GTR) with limited salvage options. Transarterial therapies may provide treatment opportunities in AM patients who exhausted standard-of-care therapy. In cases where favorable tumor vasculature and particle simulation demonstrate acceptable target dose, Yttrium-90 trans-arterial radioemobilization (TARE) could theoretically provide salvage therapy. A 67-year-old man presented with recurrent AM post gross total resection with adjuvant radiotherapy in 2012, 2014, and 2016. The patient was deemed a poor candidate for additional therapies. Tumor vasculature mapping was performed to determine TARE candidacy. Super-selective angiography and contrast-enhanced cone-beam computed tomography angiosomes demonstrated predominant pial collaterals and minor supply from a middle meningeal artery branch. Particle simulation was performed by infusing 0.3 mCi of 99mTc-macroaggregated albumin (99mTc-MAA). SPECT/CT-MRI fusion demonstrated conformal activity solely within the tumor volume perfused by the middle meningeal artery branch with a lung shunt fraction of 54.7%. The patient subsequently received off-label Nivolumab (PD-1 inhibitor). Mapping angiography for AM using 99mTc-MAA is feasible. It may identify candidates for TARE and potential AM patients with favorable blood supply. The potential for conformal intracranial vascular brachytherapy is intriguing, however, altered arterial supply in recurrent tumors is challenging.

Increasing Yttrium-90 Dose Conformality Using Proximal Radioembolization Enabled by Distal Angiosomal Truncation for the Treatment of Hepatic Malignancy

PURPOSE

To evaluate safety and feasibility of improving radiation dose conformality via proximal radioembolization enabled by distal angiosomal truncation where selective administration was not practical.

MATERIALS AND METHODS

Hepatic malignancies treated via angiosomal truncation between January 2017 and March 2019 were retrospectively evaluated. Thirty-three patients (8 women, 25 men; mean age, 62.2 y; range, 36-78 y) underwent 39 treatments. Of treatments, 74.3% (n = 29) were for hepatocellular carcinomas, 10.2% (n = 4) were for cholangiocarcinomas, and 15.4% (n = 6) were for metastatic tumors (1 colorectal adenocarcinoma, 1 pancreatic adenocarcinoma, 3 melanomas, and 1 endometroid carcinoma). Truncation was achieved using temporary embolic devices including a microvascular plug, detachable coil, gelatin slurry, and balloon microcatheter, after which proximal radioembolization was performed. Range of treatment activity was 0.47-5.75 GBq. Technetium-99m macroaggregated albumin and bremsstrahlung single photon emission computed tomography (CT)/CT threshold analysis was conducted to delineate and compare distribution of activity within the treatment angiosome before and after radioembolization.

RESULTS

Dosimetric analysis of 14 patients demonstrated a significant reduction in nontarget liver radiation exposure at 5, 20, and 40% thresholds (P = .002, P = .001, and P = .008, respectively). There were no grade 3 or higher adverse events. There was no significant change in Albumin-Bilirubin grade and Eastern Cooperative Oncology Group Performance Status (P = .09 and P = .74) before and 3 months after the procedure. Truncated arteries were patent on subsequent angiography in 11 cases and on MR angiography or CT angiography in 38 of 39 cases.

CONCLUSIONS

Proximal radioembolization enabled by distal angiosomal truncation is safe and decreases nontarget parenchymal radioembolization dose in cases not amenable to selective administration.

Transchondral access for irreversible electroporation of hepatocellular carcinoma

Ablative treatment for hepatocellular carcinoma is standard of care in selected settings and is endorsed by international societal guidelines. Centrally located hepatocellular carcinoma are difficult to treat due to their proximity to vasculature and central bile ducts. Irreversible electroporation is a nonthermal ablation modality that has been shown to preserve the extracellular matrix and is less likely to damage structures such as bile ducts and is not susceptible to vascular heat sink. Successful irreversible electroporation requires the parallel placement of probes which can be prevented by ribs or the sternum. This case report describes the use of the coaxial bone biopsy system to enable transchondral access and facilitate parallel placement of probes during irreversible electroporation IRE for the treatment of hepatocellular carcinoma.

Endovascular Treatment of Aortohepatic Conduit Stenosis Following Liver Transplant

BACKGROUND

Aortohepatic conduits (AHCs) are valuable alternatives when conventional hepatic artery anastomoses are not possible. However, AHCs have earlier and higher occlusion rates and reduced graft and patient survival. While endovascular therapy is safe and effective for conventional anastomotic stenoses, data on AHC stenoses are limited. This study reviewed outcomes for endovascular management of AHC stenosis at a single liver transplant center.

METHODS

A retrospective review of a prospectively maintained database was performed on the endovascular management of AHC stenosis between January 1, 2000, and December 31, 2016. Medical records, laboratory data, and imaging were analyzed for technical and hemodynamic success, primary and assisted primary patency, and patient and graft survival.

RESULTS

Seven patients underwent angioplasty a median of 142 days after transplant, and 2 required reintervention. The primary patency rate was 67% at 6 months and 22% at 1 year. The assisted primary patency rate was 83% at 6 months and 42% at 1, 3, and 5 years. Patient and graft survival were 86% at 6 months and 71%, 57%, and 38% at 1, 3, and 5 years, respectively. Four conduits were patent at last follow-up. There were no major adverse events after angioplasty. One reintervention was complicated by acute AHC thrombosis after stenting, causing biliary necrosis, sepsis, and death. There was no 30-day mortality, retransplant, or surgical revascularization because of endovascular intervention.

CONCLUSIONS

Endovascular treatment of AHC stenosis appears to be safe with a high technical success rate but lower long-term patency than standard hepatic arterial anastomoses.

Acute Mesenteric Ischemia Remains a Highly Morbid Diagnosis after Initial Hospitalization Survival

Acute mesenteric ischemia (AMI) remains a vascular emergency. Our aim was to explore readmission for AMI. We identified all patients admitted for AMI from the state of California through the Healthcare and Utilization Project from 2005 to 2011. Our primary end point was the rate and etiology for readmission. Our secondary end points were the length of hospitalization and in-hospital mortality. Cox proportional hazard regression was utilized to assess risk of 30-day readmission. There were 534 (9.9%) readmissions at 30 days. The mean age was 67 ± 17 years and 209 (39.1%) were male. The five most common etiologies for readmission were AMI (7.6%), cardiac events (5.3%), severe sepsis (1.2%), dehydration (1.1%), and acute kidney failure (1.1%). Once readmitted, these patients were most likely to experience cardiac catheterizations (25.4%), red blood cell transfusions (23.6%), intubation and mechanical ventilation (17.6%), biopsy of the large intestine (13.9%), reoperation for small bowel resection (10.9%), administration of total parenteral nutrition (10.5%), and transfusion of other blood products (6.9%). This hospitalization was 8.8 ± 12.7 days long. In-hospital mortality was 36 patients (6.7%). On multivariable Cox-regression analysis, severe (hazard ratio [HR]: 2.1 [1.4-3.2], p  = 0.0005) and moderate (HR: 1.5 [1.03-2.13], p  = 0.04) Elixhauser Comorbidity Group, complications (HR: 1.5 [1.2-1.9], p  = 0.0007), and longer index hospitalization (HR: 1.02 [1.01-1.02], p  < 0.0001) were predictors of readmission. Conclusion  AMI remains a vascular emergency. Readmissions have a significant rate of morbid invasive procedures and can lead to an in-hospital mortality of 6.7%. The adoption of guidelines similar to the European Society for Trauma and Emergency Surgery should be considered.

Renal artery injury during inferior vena cava filter removal with endobronchial forceps

Retrieval of tip-embedded inferior vena cava filters using endobronchial forceps is a well-described technique. The tip of dorsally tilted filters may be in proximity to the right renal artery, increasing the risk of arterial injury during retrieval. We present one case that illustrates renal artery injury requiring emergent stent graft repair. The three subsequent cases illustrate techniques that avoid renal artery injury using a femoral and jugular approach with the assistance of an arterial fiducial wire. Renal artery injury is a potential complication during retrieval of filters using endobronchial forceps that can be prevented with careful planning.

Intraoperative Irreversible Electroporation in Locally Advanced Pancreatic Cancer: A Guide for the Interventional Radiologist

Efforts to improve mortality associated with locally advanced pancreatic cancer (LAPC) have shown minimal gains despite advances in surgical technique, systemic treatments, and radiation therapy. Locoregional therapy with ablation has not been routinely adopted due to the high risk of complications associated with thermal destruction of the pancreas. Irreversible electroporation (IRE) is an emerging, nonthermal, ablative technology that has demonstrated the ability to generate controlled ablation of LAPC while preserving pancreatic parenchymal integrity. IRE may be performed percutaneously or via laparotomy and will commonly involve multidisciplinary treatment teams. This article will describe the technical aspects of how multidisciplinary IRE is performed during laparotomy at a single tertiary care institution.

Ablation plus Transarterial Embolic Therapy for Hepatocellular Carcinoma Larger than 3 cm: Science, Evidence, and Future Directions

Thermal ablation is widely regarded as definitive therapy for early-stage hepatocellular carcinoma, but its efficacy decreases in tumors greater than 3 cm. Extensive clinical studies have supported improved outcomes provided through combining transarterial embolic therapy with ablation in the treatment of larger tumors. This article will provide a survey of the science and data for combination therapy in both thermal and nonthermal ablation modalities, as well as describe emerging applications.

Individualized Ablation of Hepatocellular Carcinoma: Tailored Approaches across the Phenotype Spectrum

Ablation is now recommended by international guidelines for the definitive treatment of hepatocellular carcinoma (HCC). Extensive clinical studies have demonstrated outcomes comparable to surgical resection with shorter hospital stays, decreased costs, and improved quality of life. Successful ablation requires complete treatment of both tumor and margin while preserving critical adjacent structures. HCC exhibits highly variable presentations in both anatomic involvement and biology which have significant implications on choice of ablative therapy. There are now abundant ablation modalities and adjunctive techniques which can be used to individualize ablation and maximize curative results. This article provides a patient-centered summary of approaches to HCC ablation in the context of patient performance, hepatic reserve, tumor phenotype and biology, intra- and extrahepatic anatomy, and ablation technology.

Percutaneous Computed Tomography-Guided Radiotracer-Assisted Localization of Difficult Pulmonary Nodules in Uniportal Video-Assisted Thoracic Surgery

Objective: To report our institutional experience with radiotracer-assisted localization of lung nodules (RALN) in combination with uniportal video-assisted thoracoscopic surgery (UVATS). Methods: We retrospectively reviewed electronic medical records and radiology images of 27 consecutive adult patients who underwent planned UVATS lung resections combined with RALN from January 2014 to May 2017. Based on preoperative imaging, 29 nondescript nodules were marked with technetium 99 m macroaggregated albumin under computed tomography guidance before resection. Perioperative outcomes were analyzed. Results: All 29 nodules were successfully marked and resected with negative margins by UVATS; 12 (41.5%) were pure ground-glass opacities. Three patients had prior ipsilateral lung resections. There were no conversions to multiport VATS or thoracotomy. The majority (86.5%) of the nodules were malignant. The median nodule size was 8 mm (range: 3-20 mm) and depth, 56 mm (range: 22-150 mm). The majority (21/27; 77.8%) of patients underwent wedge resections alone, while 6 patients had anatomical resections. Median times were as follows: radiotracer injection to surgery, 219 minutes (range: 139-487 minutes); operative time, 85.5 minutes (32-236 minutes); chest tube removal, 1 day (range: 1-2 days); and length of stay, 2 days (range: 1-4 days). Four patients (14.8%) had a pigtail catheter placed for pneumothorax after radiotracer injection. One patient was readmitted 1 week after discharge for a spontaneous pneumothorax. There were no other morbidities or any 90-day mortality. Conclusion: RALN can be combined with UVATS to effectively resect small, deep, or low-density lung lesions that are difficult to visualize or palpate by thoracoscopy.

Angiosomal radiopathologic analysis of transarterial radioembolization for the treatment of hepatocellular carcinoma

PURPOSE

To assess the radiopathologic correlation following Yttrium-90 transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC) using variable radiodosimetry to identify imaging surrogates of histologic response.

METHODS

Twelve patients with HCC underwent ablative (≥ 190 Gy) and/or non-ablative (< 190 Gy) TARE delivered in a segmental, lobar, or combined fashion as a surgical neoadjuvant or bridge to transplantation. Both targeted tumor and treatment angiosome were analyzed before and after TARE utilizing hepatocyte-specific contrast-enhanced MRI or contrast-enhanced CT. Responses were graded using EASL and mRECIST criteria. Histologic findings including percent tumor necrosis and adjacent hepatic substrate effects were correlated with imaging features.

RESULTS

Complete pathologic necrosis (CPN) was observed in 7/12 tumors post-TARE. Ablative and non-ablative dosing resulted in CPN in 5/6 and 2/6 tumors, respectively. Hyperintensity on T2-weighted imaging, the absence of hepatocyte-specific gadolinium contrast uptake, and plateau or persistent enhancement kinetics in the angiosome correlated with CPN and performed similarly to EASL and mRECIST criteria in predicting CPN.

CONCLUSIONS

The absence of hepatocyte-specific contrast uptake, increased signal on T2-weighted sequences, and plateau or persistent enhancement in the angiosome may represent MRI surrogates of CPN following TARE of HCC. These findings correlated with EASL and mRECIST response criteria. Further investigation is needed to determine the role of these findings as possible adjuncts to conventional imaging criteria.

Endovascular treatment of a high-flow hepatic arteriovenous malformation with secondary portal hypertension in a dog

CASE DESCRIPTION A 17-month-old neutered female Labrador Retriever with a 3- to 4-month history of abdominal distention was referred for evaluation and treatment. CLINICAL FINDINGS Evaluation of a peritoneal fluid specimen collected by the referring veterinarian indicated a pure transudate. At admission, transabdominal ultrasonography revealed microhepatica, dilation of the intrahepatic and mesenteric vasculature, peritoneal effusion, and multiple aberrant blood vessels. A large, high-flow hepatic arteriovenous malformation (HAVM) with secondary portal hypertension, peritoneal effusion, multiple acquired portosystemic shunts, and microhepatica was evident on CT angiography. TREATMENT AND OUTCOME Transfemoral hepatic arteriography and staged coil and glue (n-butyl cyanoacrylate) embolization of the complex arteriovenous malformation nidus and central main left hepatic artery resulted in ablation of the lesion, restoration of arterial blood flow to the contralateral hepatic lobes, and resolution of the peritoneal effusion. The dog remained without clinical signs of hepatic disease until it was euthanized 5 months after treatment for an unrelated condition. CLINICAL RELEVANCE Successful endovascular management of a HAVM was accomplished by means of coil and glue embolization in the patient of this report. Dogs with comparable HAVMs may benefit from similar minimally invasive treatment.

Radiofrequency vs Microwave Ablation After Neoadjuvant Transarterial Bland and Drug-Eluting Microsphere Chembolization for the Treatment of Hepatocellular Carcinoma

AIM

To retrospectively compare the initial response, local recurrence, and complication rates of radiofrequency ablation (RFA) vs microwave ablation (MWA) when combined with neoadjuvant bland transarterial embolization (TAE) or drug-eluting microsphere chemoembolization (TACE) for the treatment of hepatocellular carcinoma (HCC).

METHODS

A total of 35 subjects with Barcelona Clinic Liver Cancer (BCLC) very early and early-stage HCC (range: 1.2-4.1cm) underwent TAE (23) or TACE (12) with RFA (15) or microwave ablation (MWA) (20) from January 2009 to June 2015 as either definitive therapy or a bridge to transplant. TAE and TACE were performed with 40-400μm particles and 30-100μm plus either doxorubicin- or epirubicin-eluting microspheres, respectively. Initial response and local progression were evaluated using modified response evaluation criteria in solid tumors. Complications were graded using common terminology criteria for adverse events version 5.0.

RESULTS

Complete response rates were 80% (12/15) for RFA + TAE/TACE and 95% (19/20) for MWA + TAE/TACE (P = 0.29). Local recurrence rate was 30% (4/12) for RFA + TAE/TACE and 0% (0/19) for MWA + TAE/TACE. Durability of response, defined as local disease control for duration of the study, demonstrated a significant difference in favor of MWA (P = 0.0091). There was no statistical difference in complication rates (3 vs 2).

CONCLUSIONS

MWA and RFA when combined with neoadjuvant TAE or TACE have similar safety and efficacy in the treatment of early-stage HCC. MWA provided more durable disease control in this study; however, prospective data remain necessary to evaluate superiority of either modality.

Temporary percutaneous T-fastener gastropexy and continuous decompressive gastrostomy in dogs with experimentally induced gastric dilatation

OBJECTIVE To evaluate a percutaneous, continuous gastric decompression technique for dogs involving a temporary T-fastener gastropexy and self-retaining decompression catheter. ANIMALS 6 healthy male large-breed dogs. PROCEDURES Dogs were anesthetized and positioned in dorsal recumbency with slight left-lateral obliquity. The gastric lumen was insufflated endoscopically until tympany was evident. Three T-fasteners were placed percutaneously into the gastric lumen via the right lateral aspect of the abdomen, caudal to the 13th rib and lateral to the rectus abdominis muscle. Through the center of the T-fasteners, a 5F locking pigtail catheter was inserted into the gastric lumen and attached to a device measuring gas outflow and intragastric pressure. The stomach was insufflated to 23 mm Hg, air was allowed to passively drain from the catheter until intraluminal pressure reached 5 mm Hg for 3 cycles, and the catheter was removed. Dogs were hospitalized and monitored for 72 hours. RESULTS Mean ± SD catheter placement time was 3.3 ± 0.5 minutes. Mean intervals from catheter placement to a ≥ 50% decrease in intragastric pressure and to ≤ 6 mm Hg were 2.1 ± 1.3 minutes and 8.4 ± 5.1 minutes, respectively. After catheter removal, no gas or fluid leakage at the catheter site was visible laparoscopically or endoscopically. All dogs were clinically normal 72 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE The described technique was performed rapidly and provided continuous gastric decompression with no evidence of postoperative leakage in healthy dogs. Investigation is warranted to evaluate its effectiveness in dogs with gastric dilatation-volvulus.

High-volume hydrodissection for abdominally based free flaps: Preliminary results

INTRODUCTION

A novel method of high-volume hydrodissection that provides both subfascial and intramuscular perforator dissection of deep inferior epigastric perforators has been safely demonstrated in animals. This manuscript demonstrates our preliminary results when translating this technique to humans.

METHODS

A retrospective review was performed of all free-flap breast reconstructions utilizing the high-volume hydrodissection technique performed by the senior author (DS) at the University of Florida Medical Center from January 2014 to June 2015.

RESULTS

Twenty-one patients underwent 31 free-flap breast reconstructions during the study period utilizing the high-volume hydrodissection technique. No patients were lost to follow-up which averaged 8.2 months. Complications included 1 partial flap necrosis (<10%), 1 breast hematoma, 1 abdominal bulge, 2 flaps with minimal fat necrosis (<5%), and 1 abdominal wall cellulitis.

CONCLUSION

High-volume hydrodissection is a safe technique to facilitate dissection of abdominally based free flaps for breast reconstruction. © 2015 Wiley Periodicals, Inc. Microsurgery 37:307-311, 2017.