Seroma control in axillary lymphadenectomy with Glubran 2® without drain. Multicenter, prospective, randomized, clinical trial. GALA-ND study (Glubran, Axillary Lymphadenectomy, Ambulatory, No Drain).

BACKGROUND: Seroma after breast cancer surgery is a frequent entity; therefore, different products have been described in literature with the aim to reduce it. The most studied ones have been the sealants products, being tested with aspirative drains. Symptomatic seroma represents the 19% after axillary lymphadenectomy without drains. The aim of this study is to analyze the effect of a sealant in the seroma control after axillary lymphadenectomy without drains and identify the risk factors related to symptomatic seroma. METHODS: This is a prospective, multicenter, international, and randomized clinical trial. Patients undergoing conservative surgery and axillary lymphadenectomy for breast cancer will be randomized to control group (lymphadenectomy without sealant) or interventional group (lymphadenectomy with sealant Glubran 2®). In any of the study groups, drains are placed. Patients who received neoadjuvant treatment are included. Measurements of the study outcomes will take place at baseline; at 7, 14, and 30 days post-surgery; and at 6-12 months. The primary outcome is symptomatic seroma. Secondary outcomes are seroma volume, morbidity, quality of life, and lymphedema. DISCUSSION: Several studies compare the use of sealant products in axillary lymphadenectomy but generally with drains. We would like to demonstrate that patients who underwent axillary lymphadenectomy could benefit from an axillary sealant without drains and reduce axillary discomfort while maintaining a good quality of life. Assessing the relationship between axillary volume, symptoms, and related risk factors can be of great help in the control of seroma in patients who received breast cancer surgery. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05280353. Registration date 02 August 2022.

Diagnosis of breast implant associated anaplastic large cell lymphoma by analysis of cytokines in peri-implant seromas.

More than 1300 women with breast implants have developed an anaplastic large cell lymphoma (ALCL) in fluid (seroma) around their implant. More often, seromas are due to benign causes, for example, capsule contracture, leakage, or trauma. Our report in American Journal of Hematology identified several cytokines (IL-9, IL-10, IL-13) as significantly elevated only in seromas due to ALCL. We further showed that the most robust biomarker, IL-10, could be detected by a lateral flow assay (similar to COVID detection) within minutes allowing physicians to quickly plan management, eliminate or reduce costly testing and patient time away from family. Early detection of ALCL in seromas before infiltration may avoid need for cytotoxic or immunotherapy and is possibly life-saving.

Clinical Implications and Management of Non-BIA-ALCL Breast Implant Capsular Pathology.

SUMMARY: The breast implant capsule is a dynamic structure that forms following the implantation of a device. Although normally benign, increased awareness of breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) highlights that disease may arise from the capsule. BIA-ALCL presents as a late seroma or mass but explains few of the late seromas found in breast implant patients. To date, many of these seromas lack a clear cause and are often described as "idiopathic." Several benign and malignant breast implant capsular diseases can cause a late seroma or mass, including breast implant-associated squamous cell carcinoma. Similar to early reports of BIA-ALCL, these conditions are rare and largely limited to case reports or series. The purpose of this special topic is to present a narrative review highlighting capsular abnormalities that contribute to the formation of late seroma or mass in an attempt to broaden the differential diagnosis and help plastic surgeons identify the cause. Specifically, we review the presentation and management of BIA-ALCL, synovial metaplasia, capsular epithelialization, late hematoma, double capsule, breast cancer, squamous cell carcinoma, mesenchymal tumor, and B-cell lymphoma. Although rare, plastic surgeons should consider these capsular conditions as causes of late seromas and masses. Usually, these conditions may be diagnosed by following the National Comprehensive Cancer Network screening guidelines for BIA-ALCL. Thorough evaluation and workup of late seromas and masses may lead to improved characterization of these rare breast implant capsular conditions and improve our understanding of their pathophysiology and management.

Prophylactic negative pressure wound therapy on wound complications after cesarean delivery in women with obesity: a meta-analysis of randomized controlled trials.

OBJECTIVE: This systematic review and meta-analysis of randomized controlled trials aimed to assess whether negative pressure wound therapy affects the rate of wound complications when applied to women with obesity after cesarean delivery compared with standard postoperative dressings. DATA SOURCES: This research used PubMed, Scopus, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials as electronic databases, from the inception of each database to January 2021, with randomized controlled trial as the publication type. There was no restriction applied for language or geographic location. STUDY ELIGIBILITY CRITERIA: The selection criteria included only randomized controlled trials comparing the effect of negative pressure wound therapy with that of standard dressings on wound complications in women with obesity undergoing cesarean delivery. METHODS: The primary outcome was a wound complication composite outcome (wound infection, separation or dehiscence, hematoma, seroma, or readmission secondary to a wound concern). The wound complication composite was analyzed by counting events once per patient. The summary measures were reported as relative risk or as mean difference with 95% confidence intervals using the random-effects model of DerSimonian and Laird. An I-squared (Higgins I2) value of >0% was used to identify heterogeneity. RESULTS: Overall, 11 randomized controlled trials, which included 5746 participants with obesity undergoing cesarean delivery, were included. Of those participants, 2869 (49.9%) were randomized to the intervention group (negative pressure wound therapy), and 2877 (50.1%) were randomized to the control group (standard dressing). Prophylactic negative pressure wound therapy was not associated with a significant change in the rate of wound complications (relative risk, 1.00; 95% confidence interval, 0.81-1.23) compared with standard postoperative dressings. However, the use of negative pressure wound therapy decreased the rate of wound infections (relative risk, 0.79; 95% confidence interval, 0.66- 0.96) and increased the frequency of skin reactions (relative risk, 4.59; 95% confidence interval, 1.29-16.38). Negative pressure wound therapy did not result in a significant difference in the rate of dehiscence, hematoma, seroma, readmission, reoperation, and antibiotic use for wound infection. CONCLUSION: Compared with standard postoperative incision dressings, negative pressure wound therapy did not affect the rate of wound complications but decreased the frequency of wound infections when applied to women with obesity after cesarean delivery. However, results should be interpreted with caution, as wound infection outcome includes different definitions per the individual trials. CONDENSATION: Prophylactic negative pressure wound therapy has no effect on overall wound complications in women with obesity after cesarean delivery compared with standard dressings.

Breast Implant-associated Anaplastic Large Cell Lymphoma Diagnosis 6 Years After Implant Removal: A Case Report.

ABSTRACT: We present a case report of a 48-year-old woman with a late-onset seroma of her left breast, 6 years after removal of her textured breast implants. At that time, she also had a late-onset seroma of her left breast, and capsulectomy was performed along with removal of the implants. The current late seroma presentation, which followed 6 years of uneventful healing, was treated with en bloc excision of the encapsulated seroma. Pathology results were concordant with locally invasive anaplastic large cell lymphoma (ALCL). Review of her previous seroma cytology from 6 years ago was performed given the current updated guideline standards on breast implant-associated ALCL (BIA-ALCL). Evidence of BIA-ALCL confirmed the patient had the diagnosis 6 years ago. The disease persisted and remained indolent for 6 years and manifested clinically as a late seroma of the left breast. This case report emphasizes the high degree of suspicion that is required in late seroma cases involving textured breast implants or a history of textured breast implants, along with the need for en bloc capsulectomy as a primary treatment for diagnosed BIA-ALCL to avoid incomplete capsulectomy and recurrence of the disease.

Superficial Parotidectomy: Impact of Postoperative Drainage.

BACKGROUND: Use of suction drain after superficial parotidectomy (SP) is based on national consensus considered best practice, but there is no evidence on the effect of the treatment. The aim of the present study is to evaluate the effectiveness of drainage after SP by evaluating the rate of complications after SP in relation to the (ie, duration) of drainage and tumor size. METHODS: Retrospective analysis was performed involving data from all consecutive patients undergoing SP at the Ear, Nose, and Throat department, Regional Hospital West Jutland, Denmark, between January 1, 2011, and December 31, 2017. Demographics including comorbidity, medication, tumor size, postoperative secretion through the drainage, as well as complications (hematoma, seroma, infection, fistulas, Frey syndrome, facial nerve palsy) were registered. Patients with secretion below 25 mL were compared to patients with secretion above 25 mL, that is, drainage less than 24 hours versus longer than 24 hours. Results: Two hundred five consecutive patients undergoing SP were enrolled. The overall risk of postoperative infection was 16.2%. Ten of 33 patients with infection were also diagnosed with an hematoma or seroma. The risk of infection increased with secretion above 25 mL (27.2%) compared to patients with less than 25 mL (13.1%; P = .0318). The same accounts for the risk of seromas/hematomas (P = .0055). We found no evidence that demographics or comorbidity correlated to the secretion in the drainage, but there is a tendency toward male gender having a higher risk off secretion above 25 mL (odds ratio 1.39). CONCLUSION: Overall, the risk of complications after SP increased with secretion beyond 25 mL (ie, drainage for more than 24 hours). This applied in particular to infections and seromas/hematomas demanding treatment. The use of routine drainage after SP is questionable, and a randomized trial is warranted to unravel the necessity of postoperative drainage.

Reduction of seroma and improvement of quality of life after early drain removal in immediate breast reconstruction with tissue expander. Preliminary report from a randomized controlled study.

Seroma is the most common complication of breast reconstruction with tissue expander (incidence 0.2-20%) with increased risk of infection and implant loss by 4-6 fold. About 90% of plastic surgeons routinely placed drains for its prevention. We theorized that early drain removal is a safe procedure that improves postoperative quality of life (QoL), reducing pain, length of hospital stay, and limitations on daily activities. We divided 49 patients operated on between September 2016 and March 2018 (follow-up: 9-26 months) into two groups: Group1 (output-based; drains removed when <30 ml/day); and Group2 (early-removal; at 3-4 days postop.). A study-specific questionnaire about the patient's QoL was conducted 3 weeks after surgery. We performed an intention-to-treat analysis. A comparison was performed using a Fisher test and a Mann-Whitney U test with p = 0.05. We observed lower production of wound fluid (641±49 ml vs 231±20 ml; p = 0.004), and a shorter time until wound healing (31.3±4.2 days vs 22±3.9 days; p = 0.031) for Group 2. The difference for infection (p = 0.36), impaired wound healing (p = 0.22), and the seroma formation period (p = 0.11) was not significant. Group 2 experienced less breast pain (8% vs 87.5%; p = 0.001), fewer limitations in daily activities (16% vs 50%; p = 0.002), in mobility (20% vs 83.3%; p = 0.001), and in social life (8% vs 91.7%; p < 0.001), and a better quality of sleep than Group 1 (36% vs 75%; p = 0.002). Group 2 did not require home care after hospital discharge (p < 0.001). The limitations of study are: its small sample size, the wound healing assessment, and the use of a non-validated questionnaire.

Delayed periprosthetic seroma in a male Poland syndrome patient: A case report.

RATIONALE: Custom-made implant is an accepted treatment option for treatment of chest deformity in Poland syndrome. Unlike the raised concerns and awareness for the long-term consequences of breast implants, the long-term complications of customized implants for special purposes like Poland syndrome has not been reported in the literature. PATIENT CONCERNS: A 44-year-old male with Poland syndrome presented to our institution complaining of a large bulge and fluctuation on the right chest wall. This occurred after 14 years from the initial implant surgery for correction of chest wall deformity. Upon failure of resolution by multiple aspirations, workup was carried out under suspicion of implant associated malignancy. INTERVENTION: Total Capsulectomy and implant removal was done. OUTCOMES: Histology revealed chronic inflammation with fibrosis. Implant-associated malignancy was not found. He is being followed up with no signs of recurrence. LESSONS: For rare cases of implant insertion such as Poland syndrome, awareness of delayed complications and workups based on suspicion of implant-associated malignancy is needed. Surgeon awareness and patient education is required.

Local Triamcinolone Treatment Affects Inflammatory Response in Seroma Exudate of Abdominoplasty Patients: A Randomized Controlled Trial.

BACKGROUND: As the leading complication of abdominoplasty, seroma formation might represent an inflammatory process in response to surgical trauma. This prospective randomized trial investigated whether local administration of the antiinflammatory agent triamcinolone could prevent seroma accumulation. METHODS: Weekly and cumulative seroma volumes were compared between the study groups A, B, and C over a 4-week follow-up (group A, with drain, without triamcinolone; group B, without drain, without triamcinolone; group C, without drain, with triamcinolone). Aspirated seroma samples were analyzed by enzyme-linked immunosorbent assay for selective inflammatory mediators. RESULTS: Triamcinolone significantly reduced cumulative seroma volume (n = 60; mA 845 ± SDA 578 ml, mC 236 ± SDC 381 ml, p = 0.001). The most accentuated suppressive effect of triamcinolone was observed shortly after the treatment (week 1) (mA1 616 ± SDA1 457 ml, mB1 153 ± SDB1 161 ml, mC1 22 ± SDC1 44 ml, pA1/C1 < 0.001, pB1/C1 = 0.014). Local triamcinolone administration resulted in a differential concentration of interleukin-6 (IL-6) and matrix metalloproteinase-9 (MMP-9 (week 1) in seroma exudate as measured by enzyme-linked immunosorbent assay (mIL-6A1 1239 ± SDA1 59 pg/ml, mIL-6C1 848 ± SDC1 80 pg/ml, p < 0.001; mMMP-9A1 2343 ± SDA1 484 pg/ml, mMMP-9C1 376 ± SDC1 120 pg/ml, p = 0.001). CONCLUSIONS: Local administration of 80 mg of triamcinolone reduced postabdominoplasty seroma accumulation significantly. Under triamcinolone treatment, suppressed levels of IL-6 and MMP-9 in seroma fluid were observed. Notably, inflammatory marker suppression correlated clinically with a decrease in seroma accumulation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Sarcoidosis Presenting as Late Seroma Mimicking Breast Implant-Associated Anaplastic Large Cell Lymphoma.

ABSTRACT: Late seroma related to breast silicone implants is a rare complication. Interest for its characterization has grown after its association with the recently described breast implant-associated anaplastic large cell lymphoma. The differential diagnosis includes infectious diseases, mechanical and traumatic causes, tumors, postpartum seroma, and inflammatory, allergic, or idiopathic causes.Sarcoidosis has been associated with breast silicone implants over the last decades, but it has never been reported as a cause of breast effusion. We describe a rare presentation of sarcoidosis as a late breast implant seroma simulating the clinical features and radiologic findings of breast implant-associated anaplastic large cell lymphoma and highlight that sarcoidosis can be suspected by the presence of nonnecrotizing epithelioid granulomas in the cytology, with a characteristic inverted ratio of CD4/CD8 T cells.The aims of this article are to review the current evidence about sarcoidosis related to silicone implants and breast cancer, provide a new alternative in the differential diagnosis of late seroma, and advise the scientific community how early implant removal can improve the disease.

Management of recurrent post-traumatic seroma of thigh (Morel-Lavallée lesion) by percutaneous aspiration and sclerotherapy using tetracyclines (PAST).

Morel-Lavallée lesion is a chronic, recurrent collection of serous fluid in the soft tissues and usually occurs following injury. The most common sites are thigh, hip and pelvic region. This presents as a local or diffuse swelling and may cause discomfort to the patient besides being a potential site for bacterial contamination. So, early diagnosis and timely management is crucial for an early and successful outcome. The investigation modality of choice for diagnosis of these lesions is MRI. Definitive management ranges from percutaneous aspiration with or without sclerotherapy to open debridement and irrigation. Although recurrences are common with conservative management, it can be minimised with judicious use of sclerotherapy.

Decreasing donor site morbidity after groin vascularized lymph node transfer with lessons learned from a 12-year experience and review of the literature.

INTRODUCTION: Donor site morbidity related to vascularized lymph node transfer (VLNT) remains a cause of worry among surgeons. As such, our study explores donor site morbidity after VLNT with or without concomitant deep inferior epigastric artery perforator (DIEP) flap breast reconstruction. Furthermore, we evaluate our surgical approach to ascertain whether it reduces the morbidity rate. MATERIALS AND METHODS: A retrospective chart review of donor site complications and surgical techniques was performed from 2006 to 2018. The patients' medical histories and demographic data were analyzed for risk factors. Patients were contacted by telephone for a long-term follow-up questionnaire. A literature review was implemented to evaluate the reported donor site complications and surgical strategies in literature. Complications were evaluated with and without concomitant autologous breast reconstruction (DIEP flap). RESULTS: Eighty-nine patients were included in our case series. Sixty-five cases (73%) were combined with DIEP flap breast reconstruction. Seroma rate diminished from 60% in the first 39 cases to 18% in the last five years (50 cases) (p < 0,001). Lymphedema of the afferent lower limb is described in the literature but did not occur in our series. CONCLUSIONS: Seroma formation is the most common donor site morbidity after groin VLNT flap harvest, particularly when combined with DIEP flap breast reconstruction. This paper contains the largest reported series of combined VLNT + DIEP flaps and describes surgical strategies on how to decrease seroma formation and avoid iatrogenic lymphedema of the lower limb.

External compression due to seroma of ventricular assist device outflow graft.

A 45-year-old woman with repaired complex congenital heart disease, who underwent placement of Jarvik 2000, a ventricular assist device (VAD) for 4 years, experienced abdominal pain due to outflow graft compression caused by seroma formation between the outflow graft and ringed Gore-Tex graft. We exchanged the pump of Jarvik 2000 and punched several small holes in the new ringed Gore-Tex graft. Seroma formation between the two grafts should be considered as a cause of outflow graft obstruction in patients with the long-term support of VAD, and additional surgical interventions to the ringed Gore-Tex graft may prevent this complication.

IL-10, IL-13, Eotaxin and IL-10/IL-6 ratio distinguish breast implant-associated anaplastic large-cell lymphoma from all types of benign late seromas.

Breast implant-associated anaplastic large-cell lymphoma (BI-ALCL) is an uncommon peripheral T cell lymphoma usually presenting as a delayed peri-implant effusion. Chronic inflammation elicited by the implant has been implicated in its pathogenesis. Infection or implant rupture may also be responsible for late seromas. Cytomorphological examination coupled with CD30 immunostaining and eventual T-cell clonality assessment are essential for BI-ALCL diagnosis. However, some benign effusions may also contain an oligo/monoclonal expansion of CD30 + cells that can make the diagnosis challenging. Since cytokines are key mediators of inflammation, we applied a multiplexed immuno-based assay to BI-ALCL seromas and to different types of reactive seromas to look for a potential diagnostic BI-ALCL-associated cytokine profile. We found that BI-ALCL is characterized by a Th2-type cytokine milieu associated with significant high levels of IL-10, IL-13 and Eotaxin which discriminate BI-ALCL from all types of reactive seroma. Moreover, we found a cutoff of IL10/IL-6 ratio of 0.104 is associated with specificity of 100% and sensitivity of 83% in recognizing BI-ALCL effusions. This study identifies promising biomarkers for initial screening of late seromas that can facilitate early diagnosis of BI-ALCL.

Seroma formation after modified Blalock-Taussig shunt which caused shock due to pulmonary vein compression.

Seroma formation is a relatively rare complication seen after a modified Blalock-Taussig shunt. Herein, we report a rare case of seroma formation on the posterior aspect of the left atrium without it touching the graft, and presenting with shock, due to pulmonary vein compression.

A Cautionary Tale and Update on Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL).

Breast implant-associated anaplastic large T-cell lymphoma (BIA-ALCL) was first recognized by the World Health Organization in 2016. The total number of cases worldwide continues to increase, with >800 cases confirmed through a combination of Food and Drug Administration data, verified reports, and registries. To date, 33 deaths have been reported. Typical presentation includes a late seroma containing monoclonal T cells that are CD30 positive and anaplastic lymphoma kinase negative. We present a review of the current literature and report on 3 cases of BIA-ALCL at our institution, which serve to illustrate our approach to diagnosis and management of this disease. In 2 cases, the diagnosis of BIA-ALCL was not initially confirmed due to an incomplete workup but was recognized upon explantation. The seroma fluid was sent for flow cytometry. Initially, the cells were reported as morphologically suspicious for malignancy with phenotypically normal T cells based on standard CD3+ T-cell gating. Subsequent cytology specimens were reported as consistent with recurrent adenocarcinoma. However, upon regating of flow-cytometry data, a population of CD30+, CD3- T cells was noted and the diagnosis of BIA-ALCL was confirmed by immunohistochemical stains of the excised breast capsule specimen. Given the increasing incidence of this disease, as plastic surgeons we must stay informed to order the correct workup to avoid misdiagnosis and be prepared to appropriately refer affected patients to centers with multidisciplinary teams experienced in the management of BIA-ALCL.

Posterior cord syndrome associated with postoperative seroma: The case to perform a complete neurologic exam.

Context: Posterior cord syndrome (PCS) is the least common incomplete spinal cord injury. Findings of posterior cord syndrome include loss of proprioception and vibration, which are not routinely tested with the American Spinal Cord Injury Association's International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam and can easily be missed. Seromas may develop after spinal instrumentation and can cause cord compression. Findings: This case describes a unique presentation of posterior cord syndrome following a large seroma formation after laminectomy. A patient developed ataxia with functional decline following posterior laminectomy. Examination revealed loss of vibration and proprioception in the extremities with preservation of strength. Imaging of the cervical spine demonstrated a large fluid collection at the laminectomy site causing cord compression. The fluid collection was thought to represent a seroma based on clinical presentation, imaging, and laboratory testing. The patient was admitted to inpatient rehabilitation with improvement in function allowing discharge to home. Conclusion/clinical relevance: Seromas are a complication following cervical instrumentation that can cause compression of the adjacent spinal cord resulting in functional decline. The seroma, in this case, led to the loss of vibration and proprioception with resultant ataxia, signs that are not routinely identified on ISNCSCI exam; therefore, this highlights the need to broaden the neurological examination when evaluating a patient with spinal cord injury who has experienced a neurological setback.

Seromas Following Pediatric Spinal Deformity Surgery: Is Operative Management Necessary?

BACKGROUND: Seromas are known complications after pediatric spinal deformity surgery. Although many surgeons perform an early debridement to prevent deep surgical site infections (SSIs), a less invasive approach to seroma management has not been studied. We hypothesized that a conservative approach to seroma management would be safe and yield equivalent outcomes. METHODS: We performed a retrospective review of patients who developed a postoperative seroma with or without nonpurulent drainage. Inclusion criteria were patients below 21 years who underwent primary posterior spinal fusion from 1996 to 2016 and developed a postoperative wound seroma. Seromas were clinically defined as an afebrile patient with a fluid collection that was soft and nontender to palpation and without induration or erythema. Growing spine surgeries and revision procedures were excluded from this study. RESULTS: Twenty-five of 790 total patients with a mean follow-up of 57.8 months (±48.5 mo) developed a seroma. Seromas were identified at a mean of 13.6 days postoperatively and resolved after a mean of 12.2 days following the presentation. Seromas occurred in 12 patients with idiopathic scoliosis, 12 with neuromuscular scoliosis, and 1 patient with Scheuermann kyphosis. All cases were managed conservatively with monitoring of the incision without an operative procedure. In cases of spontaneous drainage, a sterile dressing was applied to the wound and changed as needed until drainage ceased. Two patients underwent bedside needle aspiration and 5 patients received prophylactic antibiotics at the treating surgeon's discretion. All cases resolved spontaneously without development of an acute SSI. Three cases subsequently developed a late SSI (range, 18 to 38 mo postoperatively). Two had idiopathic scoliosis and 1 had neuromuscular scoliosis. None of these seromas drained spontaneously. CONCLUSIONS: Conservative management of postoperative seromas after pediatric spinal deformity surgery is appropriate. It is unclear if seromas contributed to the development of the 3 late infections. Further studies are needed regarding the relationship of late infections in seroma patients. LEVEL OF EVIDENCE: Level IV-case series.

[Huge periprosthetic (peritransplant) seroma of a femoropopliteal bypass graft]. / Gigantskaia periproteznaia (periéksplantatnaia) seroma bedrenno podkolennogo shunta.

Presented herein is a clinical case report of a huge periprosthetic seroma of a femoropopliteal bypass graft made of polytetrafluoroethylene with a follow-up period and unsuccessful conservative management of more than one year. At 15 months after the primary operation, the bypass graft was retrieved and replaced by a knitted vascular graft made of polyester and impregnated with absorbable modified gelatine to decrease porosity, without relapse of the process of transudation into the periprosthetic space. Histological study of the retrieved conduit demonstrated the absence of formation of the intimal layer on the inner surface of the graft and fibrous capsule on the external surface of the main part of the length of the prosthesis, which, apparently, had provided a possibility of long-term preservation of porosity of the material.