Evaluation of a novel synthetic sealant for inhibition of cardiac adhesions and clinical experience in cardiac surgery procedures

BACKGROUND

Pericardial adhesions subject patients requiring reoperation to potential injuries to the heart, great vessels, and cardiac grafts during the re-sternotomy. These adhesions can severely complicate re-operations by making re-entry hazardous, impeding orientation and visibility, increasing the amount of blood loss, and prolonging the operation time. The efficacy of an in situ-forming polyethylene glycol (PEG) material, CoSeal surgical sealant (CoSeal), for inhibiting cardiac adhesions in an animal model is reported. It is currently estimated that 10-20% of patients undergoing aortic valve replacement and coronary artery bypass grafting (CABG) will require a second operation later in their lives. Successful clinical experience using CoSeal for sealing suture lines of the aorta and CABGs with the data reported here suggest that CoSeal may have multiple applications in cardiac surgery.

METHODS

In rabbits, a sternotomy and pericardiotomy were performed to expose the heart and the epicardium of the left ventricular surface. The epicardium was abraded for five minutes with dry gauze and cotton to develop punctate bleeding. In treated animals, CoSeal(R) or Tissucol(R) was applied directly to the abraded bleeding epicardium while retracting the pericardium. The pericardium was released, and the material over-sprayed to the cut edges of the pericardium. No material was applied in control animals.

RESULTS

At necropsy, CoSeal(R) was found to significantly reduce the formation of adhesions, the tenacity of the adhesions, and the percent of the abraded site with adhesions as compared to surgical control and Tissucol. Tissucol showed no significant difference from the surgical control in any adhesion parameter. CoSeal treated hearts showed re-establishment of the mesothelial layer and tissue morphology similar to a normal un-operated heart. During the clinical cardiac procedures, CoSeal was easily mixed and applied to the suture lines of the aorta and coronary artery grafts. No bleeding was found at the suture lines.

CONCLUSIONS

In the rabbit cardiac adhesion model, CoSeal significantly reduced the formation of adhesions as compared to surgical control and Tissucol, and demonstrated good biocompatibility. In CoSeal treated patients undergoing cardiopulmonary bypass or vessel repair, sealing was achieved comparable to previous cases using Tissucol fibrin sealant. CoSeal effectively sealed the suture lines of the aorta and coronary artery bypass grafts.

Treatment of suture line bleeding with a novel synthetic surgical sealant in a canine iliac PTFE graft model

CoSeal mark surgical sealant (CoSeal) was evaluated for inhibiting suture line bleeding using a canine iliac PTFE graft model. Both iliac arteries of 12 heparinized canines were grafted with PTFE. CoSeal was applied to the suture lines of one graft in each animal. The contra-lateral graft served as a control and bleeding was controlled with gauze and pressure (tamponade). The cross-clamps were removed 30 s following application of CoSeal. Times to hemostasis and volume of blood loss at each graft site were determined. Compared to tamponade control, CoSeal significantly reduced the time to hemostasis (average of 5 min vs. greater than 15 min, p < 0.05) and blood loss (19 g vs. 284 g, p < 0.05). Small amounts of CoSeal were visible grossly or histologically at day 7. Histology showed moderate to marked inflammation in CoSeal sites and moderate inflammation in control sites at day 7. At 30 and 60 days, no CoSeal was visible grossly or histologically. Histology showed moderate inflammation in both CoSeal treated sites and in control sites at day 30 and mild to moderate inflammation in both CoSeal and control sites at day 60. CoSeal significantly reduced the time to hemostasis and blood loss in comparison to tamponade.

Hereditary ochronosis: hyperpigmented skin overlying cartilaginous structures

Hereditary ochronosis, or alkaptonuria, results from deficiency of homogentisic acid oxidase. It is an autosomal recessive condition found in geographically isolated populations. The excess homogentisic acid deposits in collagenous structures, leading to unusual pigmentation of the skin overlying cartilaginous structures, but on occasion pigment is also seen in the sclera, in sweat after oxidation, and classically, in urine when left standing at room temperature. This case report highlights the pathogenesis and expression of this rare disorder.

Evaluation of artecoll polymethylmethacrylate implant for soft-tissue augmentation: biocompatibility and chemical characterization

Artecoll polymethylmethacrylate implant (Artecoll) is a combination of polymethylmethacrylate beads suspended in 3.5% atelocollagen and has been designed for use in soft-tissue augmentation applications. The biocompatibility and immunogenicity of Artecoll were evaluated to assess the safety of this product for use in the dermis. To characterize the collagen component, chemical analysis was performed including trypsin sensitivity, differential scanning calorimetry, and pepsin content. Particle size analysis was also performed on the polymethylmethacrylate beads. The ability of this material to elicit an immunologic response was measured in a sensitized and nonsensitized guinea pig intradermal model. In these studies, 24 guinea pigs were injected intradermally with either Artecoll or Zyderm, a bovine collagen product for soft-tissue augmentation. Six sites were evaluated for each material at 3, 7, and 28 days after injection. In the sensitized model, 60 guinea pigs were divided into five groups, and each group received a sensitizing dose (in conjunction with Freund's adjuvant) of Zyderm, Artecoll, or a nonsensitizing dose of the same materials. The fifth group served as a nontreatment control. After the animals were sensitized, they were challenged with intradermal injections of various antigens to evaluate delayed type hypersensitivity reactions. Chemical characterization indicated polymethylmethacrylate beads of varying sizes, including many less than 35 microns, and a vehicle of extensively denatured and impure collagen. In vivo evaluations indicated that Artecoll elicited an immune response in guinea pigs, including delayed type hypersensitivity and antibody reactions. Histological assessment demonstrated particle phagocytosis and transepidermal elimination. Following immunization with Artecoll, guinea pigs were also found to be sensitized to pepsin, an impurity found in the collagen carrier. The biocompatibility of this material was compared with that of bovine dermal collagen (Zyderm collagen implant), which is widely used and accepted as biocompatible. The results of this evaluation indicate that Artecoll polymethylmethacrylate implant has the potential to elicit an immune response in humans, and polymethylmethacrylate beads are susceptible to phagocytosis and elimination.

Birt-Hogg-Dubé syndrome: a review and presentation of the first case with oral lesions

Birt-Hogg-Dubé syndrome manifests as small, skin-colored, dome-shaped, or pedunculated cutaneous lesions. Three histopathologic patterns have been described: fibrofolliculomas, trichodiscomas, and acrochordons. The patient described in this article also had small, elevated, intraoral papules involving the mucosal surfaces of the lips, buccal mucosa, and gingivae, which represents a finding that had not been described in the literature previously.

Neutrophilic tuberculous panniculitis in a patient with polymyositis

The clinical spectrum of cutaneous M. tuberculosis infections is varied and atypical. Once a major cause of death, with the advent of antimicrobial drugs it had, until recently, been an uncommon consideration in the differential diagnosis of cutaneous disorders. Panniculitis can be caused by a variety of etiologic agents; however, only rarely has it been reported caused by tuberculosis. Herein, we describe a patient with an unusual case of neutrophilic panniculitis caused by M. tuberculosis that arose following corticosteroid therapy for presumptive polymyositis. This case illustrates the need to include mycobacterial infection in the differential diagnosis of panniculitis in immunocompromised patients, and the importance of early detection via microbiologic culture and histopathologic examination.

Primary cutaneous rhabdomyosarcoma

We report an unusual case of primary cutaneous embryonal rhabdomyosarcoma presenting as a solitary skin lesion on the anterior chest of a 20-month-old child. The tumor was characterized by small, round to oval, poorly differentiated cells. Immunohistochemically, the tumor was negative for NSE, S-100 protein, LCA, and keratin but positive for muscle-specific actin, myoglobin, desmin, and vimentin, thus indicating the presence of myogenous differentiation. Ultrastructural analysis demonstrated thick and thin filaments. Special studies showed no evidence of a primary rhabdomyosarcoma in the patient at a more typical location, nor was there any evidence of metastases.

Angiosarcoma of the face and scalp

Angiosarcomas of the face and scalp are aggressive, malignant neoplasms that are associated with a poor prognosis. Radiotherapy and chemotherapy alone have failed to give satisfactory results in the treatment of this disease, so surgery continues to play the major role in its management. In this article we report on 3 patients with angiosarcoma of the face and scalp recently seen in our institution. The clinical presentation, pathophysiology, and prognosis are extensively reviewed from the recent literature. We conclude with a discussion of treatment options in the management of this disease, with emphasis on surgical management.

Rapid detection of cutaneous herpes simplex virus infection with the polymerase chain reaction

A simple and specific method for detecting herpes simplex virus infection in routinely processed paraffin-embedded biopsy specimens is described. DNA is extracted from paraffin blocks, and subjected to DNA amplification with the polymerase chain reaction. After 40 rounds, an amplified band can be detected after agarose gel electrophoresis and ethidium bromide staining. This band is specific for herpes simplex virus, because tissues infected with related viruses do not give this amplified band. We have been able to detect viral DNA in small punch skin biopsies with this procedure, which can take as little as 6 h.

Desmoplastic malignant melanoma. A clinicohistopathologic study of 25 cases

A clinical and histologic review of 25 patients with melanocytic lesions classified as desmoplastic malignant melanoma is reported. All of the lesions were located in sun-exposed sites. The average age was 61.2 years (range, 38 to 83), with a median age of 56. There were 14 female and 11 male patients. Desmoplastic malignant melanoma is a melanocytic and fibroblastic proliferation that occurs predominantly in the head and neck area. The bland constituent cells resemble fibroblasts and are often arranged in bundles or fascicles, which may be arrayed perpendicularly to the overlying epidermis. Enlarged and/or atypical cells are usually scattered among the spindled cells. Most, but not all, of the tumors (24 of 25 in this series) are associated with lentigo maligna or an atypical junctional melanocytic proliferation. Mitotic figures are always found within the constituent cells of the fibrous-appearing mass, and neurotropism may be present. Patients with desmoplastic melanoma typically present with a mass, which is occasionally associated with a pigmented lesion. The lesions in our series were deeply invasive to level IV or V. Lentigo maligna and a dermal fibroblastic-appearing mass containing atypical cells arranged in fascicles are the most common morphologic features found in desmoplastic melanoma. Follow-up data is available for 23 patients. The average length of follow-up was 2.7 years (range, 0.1 to 9 years). Eighteen patients were observed for 3 or more years. Twelve patients developed local recurrences, and five developed metastases; three of the patients with metastases had a local recurrence before the development of metastases. Three of the patients with metastatic melanoma died of tumor between 2 and 4 years after their initial excision. Eight of the 12 locally recurring lesions were either diagnosed initially as a benign lesion or histologic examination was not performed on the initial excision specimen. It appears that recurrence may be related to inadequate initial therapy.

Lymphomatoid papulosis expresses immunophenotypes associated with T cell lymphoma but not inflammation

Twelve skin biopsy specimens of lymphomatoid papulosis from nine patients were studied immunohistologically. The large atypical cells morphologically resembled Reed-Sternberg cells in six cases and large cerebriform mononuclear cells in three cases. These cells expressed pan-T cell antigens (Leu-4 and/or Leu-5) and helper T cell antigen (Leu-3) in each case. They also expressed activation antigens: HLA (human lymphocyte antigen)-DR, HLA-DQ, Tac, and T9. Reactivity of many nuclei with Ki-67 indicated a high proliferative index. Phenotypic abnormality of the large atypical cells was evident by their deficiency of T cell antigens Leu-1 and/or Leu-9 in eight of nine cases. Neither Ki-1 nor Leu-M1 were reliable markers for lymphomatoid papulosis in this series, since large atypical cells were Ki-1-positive in only three of eight cases and were Leu-M1-negative in all eight cases tested. The remainder of the cutaneous infiltrate consisted of small T cells, macrophages, Langerhans cells, and granulocytes. The small T cells expressed a normal phenotype except in some cases associated with mycosis fungoides in which they were deficient in various T cell antigens. Comparison of concurrent lymphomatoid papulosis and mycosis fungoides skin biopsy specimens in two patients revealed that they were composed of phenotypically distinct T cell subpopulations. These results indicate that the large atypical cells of lymphomatoid papulosis are a proliferating population of activated helper T cells that are deficient in certain T cell antigens. Such abnormal T cell phenotypes are common in T cell lymphoma but are rarely, if ever, observed in cutaneous inflammation. In conjunction with the cytologic atypia, aneuploidy, and association with other lymphomas documented in this or previous reports, these data suggest that lymphomatoid papulosis represents a T cell lymphoproliferative disorder rather than an inflammatory disorder.

Carcinogen bioassay of enflurane in mice

A carcinogen bioassay of enflurane was performed in Swiss/ICR mice. Two groups of weanling mice, each of 125 males and 125 females, were exposed to eigher a maximum tolerated dose of enflurane, 3000 ppm (0.3 per cent v/v) or compressed air for 4 hs per day, 5 days per week. After 52 weeks exposure, 25 males and 25 females from each group were killed. After 78 weeks exposure, a 4-week period without treatment was allowed before the remaining mice were killed. Mice killed at the scheduled periods and those killed or dying at other times throughout the study, underwent extensive gross and histologic, examinations unless autolysis or cannibalism precluded examination. After 78 weeks exposure, male mice in the enflurane-treated group had a 36 per cent incidence of liver tumors compared with 24 per cent in the control group; however, the difference was no statistically significant. The incidence of lung tumors was about 20 per cent in all groups. Other neoplastic lesions occurred in small numbers and were unrelated to treatment. It was concluded that under the conditions of the present experiment, chronic administration of enflurane at its maximum tolerated dose did not lead to an increased incidence of neoplasia in Swiss/ICR mice.

Lack of toxicity of enflurane on male reproductive organs in mice

Enflurane has been shown to increase slightly the percentage of abnormal spermatozoa in mice. To examine in more detail possible adverse effects of enflurane on male reproductive organs, 125 Swiss/ICR mice were exposed to 0.3% enflurane for up to 18 months; a control group of 125 mice was exposed concurrently to air. Exposures were for 4 hours/day, 5 days/week. After 12 months of exposure, groups of 25 enflurane-treated and control mice were killed, and chromosomal analysis of spermatogonial cells was performed. After 18 months exposure, remaining mice were killed and epididymal sperm were collected for morphologic examination. In addition, the reproductive organs of all mice dying or killed throughout the study were examined histologically. Approximately 1% of spermatogonial cells from both enflurane-treated and control mice had aberrant chromosomes. The average percentage of morphologically abnormal sperm was 9.4 +/- 1.7 for enflurane-treated mice and 6.5 +/- 1.3 for control mice; the difference was not statistically significant (p = 0.18). Finally, there was no difference between the treated and control mice in histologic appearance of reproductive organs. It was concluded that long-term exposure to enflurane has no adverse effects on male reproductive organs in mice.

Signet ring cell adenocarcinoma of the bladder: linitis plastica variant

An unusual case of the signet ring cell variant of adenocarcinoma of the bladder occurred in which the tumor extensively infiltrated the bladder wall and perivesical fascia. The pattern of infiltration was analogous to that seen in the linitis plastica variant of gastric carcinoma. Cystoscopic and roentgenographic studies failed to reveal a grossly evident lesion.

Enflurane has no effect on haemopoiesis in mice

Male and female Swiss/ICR mice were exposed to 0.3% enflurane in air, 4 h per day, 5 days per week for 52 weeks. A control group was exposed to air alone. After 52 weeks, all animals were sacrificed and peripheral blood and bone marrow samples were examined for alterations in haemopoiesis. In general, there was no difference between treated and control groups.

Effects of hyperthermia in a malignant tumor

The mechanisms of immediate and delayed tumor cell killing by hyperthermia were investigated in EMT-6 neoplasms implanted in BALB/cKa mice. Radiofrequency electromagnetic fields were used to achieve a curative local dose of 44 degrees C for 30 minutes. The tumors were sampled sequentially, during and after heat therapy, and studied by light and elecron microscopy. Assays for cell survival, including cell cultures, were performed at various times after completion of therapy. Focal cytoplasmic swelling, rupture of the plasma membrane and peripheral migration of heterochromatin were observed 5 minutes after initiation of therapy and led to cytoplasmic fragmentation by the end of the treatment period (30 minutes). Necrosis of most cells occurred 2--6 hours after the end of treatment. At 48 hours, there were no recognizable tumor cells. A scar replaced the tumor bed 14 days later. Viable (clonogenic) tumor cells were still 2% of control levels at the end of therapy and then progressively decreased to 0.0003% at 48 hours, confirming the morphologic observations and indicating that factors other than the direct effect of heat on tumor cells contributed to complete tumor eradication. Our findings, coupled with previous studies, suggest that the immediate heat induced necrosis in this tumor occurs through the mechanisms of physical changes in the plasma membrane. The delayed (post-therapy) cell death is likely due to modifications in the environment of the tumor bed.

Orbital involvement by plasmacytoma. Report of two cases

Two patients with orbital involvement of plasma cell myeloma are presented. The first patient presented an isolated plasmacytoma in the orbit; the second patient had generalized plasma cell myeloma. In both cases X-rays and computed tomographic scanning gave valuable information and biopsy confirmed the diagnosis.