[Sentinel node-positive melanoma]

Two recent randomised studies found no survival difference in patients, who had melanoma with metastasis to the sentinel node (SN) and underwent immediate complete lymph node dissection (CLND), compared with patients, who were followed closely with ultrasound scans and only underwent CLND if metastases developed. From 2018, the Danish guidelines concur: SN-positive patients will no longer undergo routine CLND, which has high morbidity, but will be followed with ultrasound scans of the SN-positive region(s) at their follow-up visits every third month for two years, then every six month for three years, except if PET-CT is performed.

Non-integrated acellular dermal matrix in breast reconstruction: a case report

Acellular Dermal Matrices have become increasing popular in breast reconstruction especially in the last decade. There is a debate on whether Acellular Dermal Matrices increase the risk of complications or not. Common complications include infection, wound dehiscence, necrosis, seroma, haematoma, capsular contracture, extrusion, loss of implant and reconstruction failure. Non-integration is not listed as a typical complication to the use of Acellular Dermal Matrices. We report a case of a completely non-integrated Acellular Dermal Matrix following breast reconstruction in a patient without significant risk factors.

Mucosal Melanoma: a Literature Review

PURPOSE OF REVIEW

Mucosal melanoma is of great interest due to its aggressive behavior and less favorable prognosis. The literature is mainly case reports and case series. Here, we will collect the knowledge on mucosal melanoma from the last decade and review the literature. The main focus is being site-specific clinical features, treatment, and prognosis.

RECENT FINDINGS

The use of immunotherapy gain ground as for others subsets of melanoma. Anti-CTLA-4 and anti-PD-1/ PD-L1 blockade in mucosal melanoma have been evaluated in recent studies. Clinical trials are ongoing. The etiology of mucosal melanomas remains unknown. Head and neck mucosal melanomas are most common. Wide excision surgery is the treatment of choice. The effect of adjuvant therapy on survival remains questionable due to the limited knowledge. Radiotherapy seems to give better local control. The overall five-year survival rate for mucosal melanomas is 0-45%. Recent data indicates that this may be improved by the immunotherapy in the years to come.

Temporal differences in the development of organ dysfunction based on two different approaches to induce experimental intra-abdominal hypertension in swine

BACKGROUND

Intra-abdominal hypertension [IAH] occurs frequently among critically ill patients and is associated with increased mortality and organ failure. Two porcine models of IAH that cause abdominal compartment syndrome [ACS] with organ dysfunction were created. We investigated whether the two methods used to create IAH - CO2 pneumoperitoneum or adding volume to the intra-abdominal space - exerted different impacts on the temporal development of organ dysfunction.

METHODS

Twenty-four 40-kg female pigs were allocated to four groups: 25 mmHg IAH with CO2 pneumoperitoneum (n = 8), >20 mmHg IAH caused by addition of volume (n = 8), and two corresponding sham groups (each n = 4). The two sham groups were later pooled into one control group (n = 8). The animals were monitored for 12 h. Repeated serial measurements were taken of group differences over time and analyzed using analysis of variance.

RESULTS

Thirty-eight percent of the animals (n = 3) in each intervention group died near the end of the 12-h experiment. Both intervention groups experienced kidney impairment: increased creatinine concentration (P <0.0001), anuria (P = 0.0005), hyperkalemia (P <0.0001), decreased abdominal perfusion pressure, and decreased dynamic lung compliance. CO2 pneumoperitoneum animals developed hypercapnia (P <0.0001) and acidosis (P <0.0001).

CONCLUSIONS

Both methods caused ACS and organ dysfunction within 12 h. Hypercapnia and acidosis developed in the CO2 pneumoperitoneum group.

[Scurvy is not entirely a historical disease]

Scurvy, lack of vitamin C, is a rare disease and is often called seafarers' disease. This case story describes a 36 year-old female patient with scurvy after a gastric bypass operation. Scurvy led to severed bullae on the skin, haemorrhagia and loose skin. After intensive care treatment and a minor split skin graft the patient was discharged from the university hospital to a local hospital for further mobilization. Three months later the patient died due to sepsis.

Microdialysis for detection of renal ischemia after experimental renal transplantation

PURPOSE

We designed an experimental renal transplantation model and evaluated microdialysis as a detector of induced postoperative ischemia, a feared complication that when caused by vascular thrombosis most often causes renal graft loss.

MATERIALS AND METHODS

Two microdialysis catheters were placed in the left kidney in 16 pigs, including 1 superficially in the renal cortex and 1 fixed on the renal capsule. Two-hour baseline measurements were made at steady state, after which the kidney was removed and subjected to warm and cold ischemia. It was subsequently re-anastomosed end to end in situ and reperfused for 5 hours. Pigs were then randomized into a total renal artery occlusion and a control group.

RESULTS

At baseline there were no changes in local metabolites (glucose, glutamate, glycerol and lactate) and no significant difference between the groups. Glycerol increased 4-fold in each group during cold ischemia but there were no pivotal alterations in other metabolites. After kidney reperfusion glycerol decreased and all metabolites were in steady state after 1 hour. At 30 minutes after postoperative ischemia was introduced there were significant increases in all kidneys in ischemia vs steady state reperfusion levels of cortical lactate, glutamate, glycerol and the lactate-to-glucose ratio (each rank sum test p <0.001). No metabolic changes were seen in controls.

CONCLUSIONS

Microdialysis detected significant metabolic changes after postoperative ischemia in pigs with experimental renal transplantation, while no metabolic changes were observed in controls. In the future microdialysis may become a valuable tool for postoperative observation of transplanted kidneys, most probably with major impact on early graft survival.

Regional changes in renal cortical glucose, lactate and urea during acute unilateral ureteral obstruction

OBJECTIVE

Acute unilateral ureteral obstruction (UUO) leads to changes in kidney function and metabolism. Microdialysis offers the possibility of topical analysis of changes in kidney metabolism. We applied microdialysis to the porcine kidney and evaluated its impact on gross kidney function. Furthermore, we investigated regional variations in renal interstitial fluid (RIF) glucose, lactate and urea during acute UUO.

MATERIAL AND METHODS

Eight anesthetized pigs were used. Microdialysis probes were inserted in the upper, middle and lower thirds of the left renal cortex and perfused with Ringer's chloride at a rate of 0.3 microl/min. Dialysates were fractionated for 30-min periods. Bilateral intrapelvic pressure, urinary output, urinary osmolality, the excretion fractions of sodium and potassium, renal blood flow and the glomerular filtration rate were measured. Subsequently, left-sided graded ureteral obstruction was initiated, using the kidney's own urine production as a counter-pressure.

RESULTS

The application of three microdialysis probes did not have any impact on kidney function. Ureteral obstruction decreased RIF glucose in the upper and lower thirds of the kidney, but not in the middle third. RIF lactate did not change. Interstitial urea increased in all regions of the kidney, but most markedly in the upper and lower poles.

CONCLUSIONS

Microdialysis is of potential value for assessing the renal interstitial milieu under different pathophysiological conditions. Ureteral obstruction resulted in regional differences in cortical metabolites, predominantly affecting the upper and lower poles.

In situ gentamicin concentrations in cortical boneAn experimental study using microdialysis in bone

We used microdialysis to study gentamicin in cortical bone and compared these results to values obtained in bone specimens. 10 healthy pigs were given an intravenous bolus of 160 mg of gentamicin. We measured reproducibility by inserting two microdialysis catheters into the cortex of tibial diaphyses and by taking samples of serum, dialysates and bone specimens during 6 hours and measuring the concentrations of this antibiotic. The peak concentrations in the two microdialysis probes and bone specimens were 3 mg/L, 2.9 mg/L and 2.6 mg/L (Anova, p = 0.3). Similarly, the areas under the curve from 0 to 6 hours (AUC6h) were 704 mg/min/L, 661 mg/min/L and 569 mg/min/L (Anova, p = 0.07). The reproducibility of the measurements of the microdialysates was evaluated with the mean AUC(6h/catheter no.1)/AUC(6h/catheter no. 2) ratio, which was 1.12. It seems that microdialysis is a suitable method for making dynamic and quantitative measurements of gentamicin in bone.

Detection of local metabolic changes after progressive and stepwise reduction of renal blood flow in pigs

PURPOSE

Vascular complications after renal transplantation causing initially only partial renal ischemia can be difficult to discover in time to save the kidney. Our aims were to design an animal model allowing progressive and stepwise reduction of the arterial renal blood flow (RBF) and to investigate whether microdialysis could detect the subsequent metabolic changes.

MATERIALS AND METHODS

Eight pigs were used. Two microdialysis catheters were placed, one in the lateral renal cortex, the other just outside the renal capsule. Baseline measurements were obtained at steady state. Five injections of 100 mu-polyvinyl alcohol (PVA) particles were administered once every hour through an angiographic catheter placed in the renal artery to cause the RBF to gradually decline. The glomerular filtration rate (GFR) was estimated by (51)Cr-EDTA.

RESULTS

One diseased animal was excluded. GFR, RBF, and all metabolites measured by microdialysis remained stable during 2 hours of baseline measurements (ANOVA; P > .05). Within 30 minutes, the first injection of PVA particles caused a reduction of RBF to 40 +/- 13% of the baseline flow (t test; P < .001 vs baseline). Significant changes in cortical lactate and glutamate as well as extracapsular glutamate were also seen, at indicating ischemia (n = 7). Cortical glucose changed 60 minutes after baseline (n = 7).

CONCLUSION

Acute, stepwise renal blood flow reduction was achieved by injection of PVA particles. An early warning of developing ischemia is provided by microdialysis. This technique could be clinically valuable because it could be instrumental in improving survival of transplanted kidneys suffering from postoperative ischemia.

Early detection of renal ischemia by in situ microdialysis: an experimental study

PURPOSE

Acute vascular thrombosis of the renal artery or vein is a feared and devastating complication after renal operations, especially transplantation. We evaluated microdialysis as a possible new tool for the rapid and reliable detection of renal ischemia in a porcine model.

MATERIALS AND METHODS

A total of 20 healthy anesthetized pigs were randomized to experiments on the left or right kidney and into 3 groups, including arterial ischemia in 8, venous ischemia in 8 and 4 controls. One microdialysis catheter was inserted superficially in the renal cortex and 1 was placed outside on the renal capsule. The contralateral kidney was removed. After 2 hours of baseline measurements ischemia was introduced by clamping the renal artery or vein in the first 2 groups. Microdialysis samples were taken every 30 minutes during baseline and the following 5 hours. The samples were analyzed for glucose, lactate, glutamate and glycerol. The mean change from baseline was analyzed for each metabolite in all groups.

RESULTS

At 30 minutes after the introduction of arterial or venous ischemia there was a significant increased mean change from baseline of glutamate, glycerol and lactate in the cortex and of glutamate extracapsularly. The mean change from baseline of glucose in the cortex decreased significantly 60 minutes after venous ischemia and 90 minutes after arterial ischemia. In controls these metabolites did not change significantly from baseline with time.

CONCLUSIONS

Microdialysis from just outside the renal capsule is a reliable tool for the early detection of acute renal ischemia. It may be used to detect acute vascular complications in the first days after renal transplantation.

In vivo efficacy and pharmacokinetics of voriconazole in an animal model of dermatophytosis

The standard treatment for tinea capitis caused by Microsporum species for many years has been oral griseofulvin, which is no longer universally marketed. Voriconazole has been demonstrated to inhibit growth of Microsporum canis in vitro. We evaluated the efficacy and tissue pharmacokinetics of oral voriconazole in a guinea pig model of dermatophytosis. Guinea pigs (n = 16) were inoculated with M. canis conidia on razed skin. Voriconazole was dosed orally at 20 mg/kg/day for 12 days (days 3 to 14). The guinea pigs were scored clinically (redness and lesion severity) and mycologically (microscopy and culture) until day 17. Voriconazole concentrations were measured day 14 in blood, skin biopsy specimens, and interstitial fluid obtained by microdialysis in selected animals. Clinically, the voriconazole-treated animals had significantly less redness and lower lesion scores than untreated animals from days 7 and 10, respectively (P < 0.05). Skin scrapings from seven of eight animals in the voriconazole-treated group were microscopy and culture negative in contrast to zero of eight animals from the untreated group at day 14. The colony counts per specimen were significantly higher in samples from untreated animals (mean colony count of 28) than in the voriconazole-treated animals (<1 in the voriconazole group [P < 0.0001]). The voriconazole concentration in microdialysate (unbound) ranged from 0.9 to 2.0 microg/ml and in the skin biopsy specimens total from 9.1 to 35.9 microg/g. In conclusion, orally administered voriconazole leads to skin concentrations greater than the necessary MICs for Microsporum and was shown to be highly efficacious in an animal model of dermatophytosis. Voriconazole may be a future alternative for treatment of tinea capitis in humans.

Intestinal microdialysis--applicability, reproducibility and local tissue response in a pig model

BACKGROUND AND AIMS

Microdialysis has been applied to the intestinal wall for the purpose of monitoring local ischemia. The aim of this study was to investigate the applicability, reproducibility and local response to microdialysis in the intestinal wall.

MATERIALS AND METHODS

In 12 pigs two microdialysis probes were inserted into the ileal wall, one in the peritoneal cavity and one in the psoas muscle. Relative recovery was measured for all probes by the no net flux method. Metabolic measurements of glucose, lactate and glycerol were performed over six hours. The ileal wall segments containing the probes were processed for histological examination.

RESULTS

Large intra- and inter-group differences in the relative recovery were found between all locations. Absolute values of metabolites showed no significant changes during the study period. The lactate in blood was 25-30% of the intra-tissue values. A severe inflammatory reaction was seen in the ileal wall around all probes.

CONCLUSION

Measurement of the relative recovery is essential for valid measurements of metabolites when using microdialysis. The inflammatory reaction around the probe in the intestinal wall is likely to affect metabolism and measurements hereof. Therefore intestinal wall microdialysis seems confined to experimental research, and future studies should consider the intra-peritoneal approach.

Application of microdialysis to cancellous bone tissue for measurement of gentamicin levels

OBJECTIVES

Knowledge concerning the distribution of antibiotics in bone tissue is valuable for pharmacokinetic and clinical use. Unfortunately, appropriate techniques are difficult to apply. We introduced microdialysis catheters to cancellous bone tissue for the investigation of gentamicin levels and compared the pharmacokinetics measured with values obtained from bone samples.

METHODS

After two microdialysis catheters had been inserted into cancellous bone, eight pigs received an intravenous bolus of 240 mg of gentamicin. Microdialysates and bone samples were obtained over a period of 6 h and drug concentrations were measured.

RESULTS

The area under the curves of the two microdialysates and bone samples were 1569, 1721 and 1533 mg.min/L (ANOVA, P=0.81). Reproducibility of the measurements from the microdialysates was defined as the mean ratio of AUC6/catheter no. 1/AUC6/catheter no. 2. This ratio was 1.02.

CONCLUSIONS

Microdialysis is a suitable, relatively non-invasive and reproducible technique for dynamic and quantitative measurement of gentamicin levels in experimental research.

The metabolism of the diabetic foot: in vivo investigation with microdialysis

BACKGROUND

Many amputations might be delayed or prevented by more effective clinical supervision of the diabetic foot ulcer. The aim of this study was to measure the local metabolism on the edge of a diabetic ulcer and compare it to healthy subcutaneous tissue.

PATIENTS AND METHODS

In 5 non-fasting diabetic patients, we inserted a microdialysis catheter into the edge of a diabetic ulcer and a reference catheter into healthy abdominal subcutaneous tissue, and recorded the local concentrations of glucose, lactate and glycerol during rest.

RESULTS

The concentrations of glucose in the ulcers were 7.8 mM (SEM 1.9) and in the reference tissue 10.6 mM (SEM 1.8) (p = 0.4). The concentrations of lactate were 2.9 mM (SEM 0.7) and 2.1 mM (SEM 0.7) (p = 0.2), while those of glycerol were 290 microM (SEM 84) vs 98 microM (SEM 7.2) (p = 0.002).

INTERPRETATION

This study shows that microdialysis can detect differences in dialysate concentrations of metabolites in diabetic ulcers and a reference tissue, providing valuable information concerning metabolites in the diabetic foot ulcer. Future studies should combine the technique with measurements of local blood flow.

[Hurricane-related orthopedic surgical admissions to an emergency department in December 1999]

INTRODUCTION

On 3 December, 1999, at 15.00 pm, hurricane Adam struck Esbjerg (Denmark). Wind velocity exceeded 33 m/s, the strongest hurricane ever recorded in Denmark during the last century. This article describes and analyses the orthopaedic impact of the hurricane on a local hospital in Esbjerg.

MATERIALS AND METHODS

We examined retrospectively all the patients treated at the Emergency Department from 3 pm on 3 December and for the following 24 hours. For comparison, we used the records of all patients treated at the Emergency Department in the same time interval on the first three Fridays in December from 1994 to 1998.

RESULTS

No hurricane-associated deaths were recorded, but the number of patients treated on 3 December was significantly higher than that recorded in the period 1994-1998 (159 versus 74, p < 0.001). The main diagnosis was similar to that of the previous years, but more people sought treatment at the Emergency Department. Sixty-eight percent of the recorded injuries were injuries to the upper and lower extremities and 22% to the head and neck.

DISCUSSION

Hurricanes can lead to substantial morbidity and mortality. Early warning is the most effective way of reducing death and injury. People should seek cover and follow the instructions given by the news media. Educational programmes for the medical staff of the Emergency Department should be made available.

[Baker's cysts in children. A retrospective study at the hospitals in the county of Rebe from 1992 to 1998]

Popliteal cysts or Baker's cysts in childhood is a rare disease usually found by the parents. The purpose of this study is to study the recurrence rate after primary surgical resection and conservative treatment of the cysts. We retrospectively found 20 children with Baker's cysts treated at Ribe Amts Hospitals during the period 1992-1998. Thirteen patients were treated conservatively and seven had a surgical resection of the cysts performed. Of the 13 conservatively treated patients the cysts was still present in six patients (46%). In seven patients the cysts had disappeared within nine months. In the surgically treated group the cysts recurred in three patients (43%). Surgical intervention for Baker's cysts in children should only be performed after thorough consideration, due to a high recurrence rate.