Effects of post-operative pain treatment using non-steroidal anti-inflammatory analgesics, opioids or epidural blockade on systemic and local immune responses in children.

BACKGROUND: Many studies have been carried out on the effects of anaesthetic drugs and methods on the immune response, but pain and its relief also affect the immune response. We measured systemic immune responses in the blood circulation and local responses in the surgical wound when non-steroidal anti-inflammatory analgesics (NSAIDs), opioids or epidural blockade was used in the peri-operative treatment of pain. METHODS: Responses were measured in 51 children, aged from 2 to 12 years and undergoing major surgery under balanced anaesthesia. Bolus doses of diclofenac intravenously (i.v.) and rectally (NSAID group), continuous i.v. infusion of oxycodone (opioid group) or continuous epidural infusion of bupivacaine + fentanyl (epidural group) were used peri-operatively for pain relief. RESULTS: The only difference related to the analgesic method was shorter duration of post-operative leucocytosis and lower phytohaemagglutinin (PHA)-induced lymphocyte proliferative responses in peripheral blood in the opioid group than in the NSAID or epidural groups. By contrast, time-related alterations were seen overall in leucocyte and differential counts, lymphocyte and their subset counts, lymphocyte proliferative responses, and in serum cortisol, C-reactive protein, plasma interleukin-6 and group II phospholipase A2 concentrations and in the appearance of different cell types in the wound. CONCLUSIONS: Post-operative pain treatments using diclofenac (NSAID), oxycodone (opioid) and epidural blockade have basically similar effects on systemic and local immune responses with only slight, probably clinically unimportant differences in children undergoing surgery under general anaesthesia.

Hyaluronic acid in incision wound fluid: a clinical study with the Cellstick device in children.

When inserted into a human incision wound, the Cellstick device harvests inflammatory cells and collects wound fluid, reflecting time-related changes in cell populations and in wound fluid composition. Hyaluronic acid has been postulated to be an important factor in scar reduction in wound healing and in scarless fetal wound healing. The aim of this work was to determine the concentration and variation of hyaluronic acid and proportions of wound cells in closed surgical wounds in children at two time points. The Cellstick device was inserted subcutaneously into the wound at the end of an elective inguinal hernia operation on 37 healthy boys, and the devices were removed 3+/-1 or 24+/-3 hours after surgery. Haluronic acid concentration was measured from the wound fluid and a differential count of the wound cells was performed. There was a significant decrease in hyaluronic acid concentration from 3+/-1 to 24+/-3 hours after surgery (p<0.001, Kruskal-Wallis anova). The variance of hyaluronic acid concentration in wound fluid differed between the wounds at the two time points (p<0.01, Levene test for homogeneity of variance). A positive correlation between hyaluronic acid concentration and patient age (r=0.91, p<0.05, Spearman) at 3+/-1 hours post surgery and between HA and wound lymphocytes (r=0.38, p<0.05, Spearman) was also found. We conclude that the hyaluronic acid concentration in wound fluid peaks early in children and decreases significantly by 3 to 24 hours after surgery, and the concentrations in the wound fluid of healthy boys are more variable 3 hours than at 24 hours after surgery.

Wound cell variation in closed surgical wounds as measured with two independent methods.

BACKGROUND AND AIMS: It is not known, to what extent the observed cellular changes in healing surgical wounds are species-, individual- or site-specific or whether they depend on the research method used. The aim of this study was to compare two independent methods for harvesting wound cells from porcine wounds after two time intervals, and to assess individual changes of wound cell composition. MATERIAL AND METHODS: In a standardised wound model in six pigs, with eight dorsal skin incision wounds in each, the Cellstick device and the Wound Edge Contact (WEC) method were used to collect inflammatory cells from the same wounds at hour 6 or 24 post-surgery. The wound cells were stained by the May-Grünwald-Giemsa (MGG) -method and counted differentially. RESULTS: A significant difference was found between the 6 and 24 hour Cellstick specimen in the proportions of wound neutrophils (p = 0.007), lymphocytes (p = 0.02) and monocytes (p < 0.001). The differential counts of wound cells within each individual animal did not significantly differ from each other. Instead, a significant difference was found in the wound neutrophils (p = 0.001), lymphocytes (p = 0.04) and monocytes (p < 0.001) between the wounds of individual animals. The WEC method revealed the same significant differences in the wound cell proportions. CONCLUSIONS: The Cellstick and the WEC method gave analogous results with equal variances from the incision wounds for up to at least 24 hours after injury.

Local and systemic immune response to surgery under balanced anaesthesia in children.

We studied perioperative changes in the immune response and compared changes in the peripheral blood with those in the wound in 20 boys (0.5-3 years) during elective inguinal surgery under balanced anaesthesia. Blood samples were drawn before premedication, immediately, and 4 or 24 h after anaesthesia. Cells from the wound were harvested with the Cellstick device, removed from the wound 4 (n=10) or 24 h (n=10) after anaesthesia. We found decreased lymphocyte counts in the peripheral blood, increased percentages of activated T lymphocytes and B lymphocytes, and decreased percentages of total T lymphocytes, T helper cells and T cytotoxic cells. The percentages of T helper cells and B lymphocytes were lower in the wound than in blood. Mitogen-induced lymphocyte proliferative responses decreased. This study demonstrates perioperative changes in the immune response in children and, as a new finding, that immune effector cells in the blood and in the wound are in a dynamic balance.

Duration of surgery and patient age affect wound healing in children.

The migration of inflammatory cells into a wound and their subsequent changes during wound healing are essential for the complex processes of tissue repair to occur. The aim of this work was to investigate the number of wound leukocytes during early wound healing at different time periods in children. Wound cells of 184 children aged 0-15 years, operated on for a benign disease in the lower abdominal region, were harvested with the Cellstick(R) device. The device was removed from the wound at 3, 6, or 24 hours after surgery and differential cell counts were performed. The cellular patterns were significantly influenced by the age of the patient and by the duration of the surgery. The proportions of neutrophils, lymphocytes, and monocytes changed significantly from 3-24 hours. Our results suggest that there is a distinct time-related change in the pattern of inflammatory cells in the early phase of wound healing in children. This pattern is affected by the age of the child and by the duration of the surgery.

Is cellulose sponge degradable or stable as implantation material? An in vivo subcutaneous study in the rat.

The long-term behaviour of cellulose sponge implants, 10 x 10 x 5 mm in size, and tissue reactions in and around them were examined in the subcutaneous tissue of the rat from 1 to 60 weeks after implantation. The cellulose sponge used was filled up with connective tissue 4 to 8 weeks after implantation. Histologically, moderate foreign body tissue reaction inside the implant, the appearance of cracks and fissures, spotty colouration, and softening of the pore walls were observed up to 16 weeks after implantation. Later, the foreign body reaction inside the sponge became milder, the spotty colouration disappeared and micropores enlarged in the viscose cellulose matrix. Histomorphometrically, the cross-sectional area of the implants and the size of the pore wall fragments decreased, and the number of pore wall fragments increased significantly. The cellulose sponge used can be regarded as a slowly degradable implantation material. However, the time needed for the total disappearance of the cellulose sponge from subcutaneous tissue is longer than the 60 weeks.

Cranio-caudal differences in granulation tissue formation: an experimental study in the rat.

This study examined potential regional differences in the deposition of granulation tissue in cellulose sponges placed in the dorsum of rats. Four cellulose sponge implants, 10 x 10 x 5 mm in size, two in cranial and two in caudal positions, were used to induce granulation tissue formation in the back of the rat. A cranio-caudal difference in connective tissue formation was assessed from 1 to 24 weeks after implantation. Granulation tissue ingrowth, measured histomorphometrically, was enhanced at 2 weeks and the surrounding capsule was thinner from 1 to 3 weeks in implants located in the cranial part of the back. In the cranial position, the number of fibroblasts, assessed semiquantitatively, was higher and the ratio of inflammatory cells to fibroblasts lower at 2-3 weeks. Also, the ratio of hydroxyproline content to total nitrogen content was higher after the first week in cranial specimens. Thus, a distinct cranio-caudal difference in the proliferative phase was observed. These results show the obvious practical considerations underlying the need for randomization or comparison between implants from exactly corresponding cranio-caudal locations.

Neurocognitive sequelae of scaphocephaly.

OBJECTIVE: Early cranioplasty for scaphocephaly has become routine in most countries. In addition to normalizing the shape of the skull, it has been found to decrease intracranial hypertension. Whether corrective surgery benefits the child's cognitive outcome has been poorly documented. DESIGN: Eighteen children whose sagittal suture showed premature fusion at birth or soon thereafter were operated on at age 1 week to 7 months. All patients healed without complications and were followed-up at regular intervals. At the age of 7.8 to 16.3 years they were examined to clarify their neurocognitive development and to compare the results with their age- and gender-matched healthy controls. RESULTS: Originally scaphocephalic children, although operated on, had mild deficiencies in auditory short-term memory and language development when examined with the general comprehension, similarities, and digit span subscales of the Wechsler Intelligence Scale for Children-Revised. In all other respects their developmental outcome was equal to that of the controls. CONCLUSIONS: Despite relative early correction of the skull shape, originally scaphocephalic children's neurocognitive performances do not reach the same level in all of the neurocognitive domains as their matched controls at school age. Early operation (

Correlation between interleukin-6 and matrix metalloproteinase-9 in early wound healing in children.

Interleukin-6 and matrix metalloproteinase-9 concentrations in the wound fluid and their associations to cellular changes were determined in early wound healing. Wound healing of 75 children who underwent elective operations was studied with the Cellstick(R) device, which was inserted into the wound at the end of the operation and removed 3 or 24 hours post-wounding. Differential counts of the wound cells and interleukin-6 and matrix metalloproteinase-9 concentrations in the wound fluid were analyzed. Interleukin-6 and the matrix metalloproteinase-9 concentrations increased in parallel (r = 0.81). The proportion of wound neutrophils increased (p < 0.0001) and lymphocytes decreased (p < 0. 0001) between the observation times. The number of wound neutrophils had a strong correlation with both interleukin-6 (adjusted R2 = 0.41, p < 0.0001) and matrix metalloproteinase-9 concentrations (adjusted R2 = 0.37, p < 0.0001). The extracellular matrix degradation process of the early wound healing seems to be closely linked to the inflammatory response. Both of these measured markers are associated significantly with the neutrophil proportion in the wound.

Connective tissue formation in subcutaneous cellulose sponge implants in the rat. The effect of the size and cellulose content of the implant.

Granulation tissue formation was studied in viscose cellulose sponges with different cellulose contents and sizes after subcutaneous implantation in rats. Samples were removed and studied histologically and histomorphometrically 1-16 weeks after implantation. The implants with lower cellulose content and smaller size were invaded by more cells and filled with connective tissue more rapidly than those with the higher content and larger size. In larger sponge implants the beneficial effect of the lower cellulose content was more conspicuous.

Biocompatibility of cellulose sponge with bone.

The purpose of this study was to investigate the biocompatibility of viscose cellulose sponge (VCS) with bone. Twenty-five Sprague-Dawley rats were used for the study. After curettage of the bone marrow from both femoral cavities, VCS (15 x 1 x 1 mm) was implanted into one femur, leaving the contralateral side empty as a control. The rats were killed 1-6 weeks after curettage, and bone formation inside the sponge was assessed by light-microscopic examination and histomorphometric assessment. Whereas normal bone formation in rat femoral cavity took place in 2 weeks after curettage, 4 weeks were needed for bone formation in the cellulose sponge. VCS is a compatible matrix for osseous tissue ingrowth and it may be useful as a scaffold for bone tissue engineering in experiments and possibly also in clinical practice.

Matrix metalloproteinase 9 level predicts optimal collagen deposition during early wound repair in humans.

BACKGROUND: This study examined two matrix metalloproteinases (MMPs) and their association with deposition of collagen during wound repair. METHODS: In 15 hernia wounds, wound fluid was collected using two Cellstick devices, which were implanted adjacent to two expanded polytetrafluoroethylene (ePTFE) tubes. MMP-2 and MMP-9 levels were analysed 24 and 48 h after operation using specific enzyme-linked immunosorbent assays, and collagen deposition in the ePTFE tubes was measured 10 days after operation as hydroxyproline. RESULTS: The levels of both MMPs in wound fluid were increased compared with those of control serum, although MMP-9 decreased (P < 0.01) in the wounds 24-48 h after operation. The MMP-9 level at 24 h correlated inversely and specifically to deposited collagen measured as hydroxyproline (rs = -0.80, P < 0.01). CONCLUSION: These results indicate that the level of MMP-9 in the early inflammatory phase can predict the amount of collagen deposited later in the wound healing process.

Treatment results of osteogenic sarcoma. An evaluation of 36 patients treated during 30-year period in south-western Finland.

Histological re-evaluation revealed 36 osteogenic sarcoma (OS) patients for analysis in South-Western Finland treated between 1958 and 1987. In 21 cases (58%) the tumour was located in the knee region. The mean age at diagnosis was 28 years (range: 5-62 years) and the follow-up time of the patients was at least 5 years or until death. In 29 patients without metastases at the time of diagnosis, the extent of the primary tumour was T2 in 37% and T3 in 63% of the patients. There were no differences regarding the extent of the primary tumour, delay of the diagnosis, mean age of the patients, or duration of the symptoms while comparing the three decades of the study. Before the 1970s the treatment consisted of surgery with or without radiotherapy in most cases. Since the 1970s the combination of surgical treatment (amputation or wide excision) and adjuvant chemotherapy was the most common treatment modality. Since the late 1970s limb-salvage surgery has been applied in selected cases, and it seems to be justified. None of the patients treated before 1970 survived for 5 years. The 5- and 10-year survival of all 36 patients was 44.4% and 33.6%, respectively. In non-metastatic patients both the 5- and 10-year disease-free survival was 46.7%. A certain group exhibiting a good prognosis was found; the 10-year survival of the 10 patients with OS in extremities, treated with combined chemotherapy and surgery, was 70%. The median survival time was significantly longer for the patients with an intracompartmental tumour extent of T2 (112 months) compared with an extracompartmental extent of T3 (23 months), and for the patients with the primary tumour in the knee region (112 months) compared with other locations (18 months). The long-term survival of the OS patients has improved concomitantly with the multimodality of the treatment.

Viscose cellulose sponge as an implantable matrix: changes in the structure increase the production of granulation tissue.

Since the 1950s a number of implantable substances have been used to study granulation tissue formation: steel mesh, polyvinylalcohol (PVA), polytetrafluoroethylene (PTFE), polyurethane, and viscose cellulose sponges (VCS). The side effects of these materials on granulation tissue formation vary considerably. An ideal material does not interfere with the normal wound-healing process and collects as many cells as possible for further analysis. Viscose cellulose sponge has been shown to be one of the most inert materials for this purpose. In this study we examined the correlation between changes in the structure of the sponge and the number of cells harvested and the synthesis of granulation tissue after subcutaneous implantation in rats. It was discovered that it is possible to control the structure of the sponge and by certain changes in this structure increase the number of invading cells and the production of granulation tissue in the sponge. There is, however, a distinct plateau after which changes in structure do not increase the number of invading cells and the production of granulation tissue in the sponge.

Prediction of wound tensile strength: an experimental study.

Wound cell specimens were obtained using a Cellstic device after 24, 48 and 72 h healing time in guinea-pig skin wounds. Cell counts from these were compared with the tensile strength values of the same wounds 7, 14 or 21 days after operation. No single cell type was predictive of wound tensile strength, although absolute numbers of different cells and selected ratios of cell types on the second or third day after operation were more predictive. Absolute and proportional changes from day 1 to day 2 had the greatest predictive power with a mean error of 9.46 per cent (F = 13.6, P less than 0.0001). The same regression model was predictive in animals with lower wound tensile strengths given perioperative hydrocortisone (3 mg/100 g).

Macrophages in trauma-induced myositis ossificans.

The basic cellular mechanisms of different forms of myositis ossificans are poorly known. In the current experiment the nature of the early (24-168 h) inflammatory cell reaction preceding trauma-induced myositis ossificans was studied. New bone formation was induced in the vastus intermedius region of the rabbit quadriceps muscle by means of immobilization and daily passive mobilization. Before the start of treatment, a cell harvesting device (viscose cellulose sponge in a silastic tube) was implanted in the region of interest. The opposite intermedius muscle and a standardized surgical skin wound served as the control sites. The results showed a significantly prolonged invasion of macrophages into the ossifying intermedius muscle as compared with the control intermedius muscle. It is hypothesized that microinjury and subsequent muscle necrosis cause the invasion of macrophages, and these cells respond to the conditions of the traumatized muscle under passive mobilization by releasing osteogenic growth factors.

Effect of haematocrit on wound healing in children.

The effects of mild or moderate normovolaemic anaemia on wound healing (WH) continue to be debatable. The results of animal experiments and clinical experience are somewhat controversial. In this study, sixty-six boys, aged from 5 to 15, mean 10.1 years, were routinely operated on for a unilateral inguinal hernia, after which their WH was studied by the Cellstic device. Based on differential count of wound cells and their mutual transformed cell to cell ratios it was found that the optimum level of haematocrit (Hct) for WH was 37-39% with haemoglobin (Hb) values of 12.0-12.4 g/100 ml. Hct values under and over these limits began to retard WH significantly (p less than 0.02) without any visual signs of delay in WH. Both values are below the age adjusted means but just above the lower limits of normal. It is thus allowed, for the majority of healthy children with normal blood values, a mild decrease of Hct during the operation without any harmful effect on WH.