Daniel Kaemmer

Evaluation of tissue components in the peripheral nervous system using Sirius red staining and immunohistochemistry: A comparative study (human, pig, rat)

Little is known about species differences in the peripheral nerve system and quantitative evaluation of main tissue components has rarely been done. Nevertheless, animal models are used for example in pain research without exact knowledge of degree of fibrosis in pathological states which would determine possible treatment options. It would therefore be of crucial interest to describe the degree of fibrosis and the remaining functional nerve tissue as exact as possible. In the present study we evaluated collagen (stroma) and nerve fiber (parenchyma) composition of peripheral nerves in three species (human, rat, pig) and used digital colour-separation and analysis for collagen type differentiation and quantification of immuno-positive-stained area. We found similar ratios of collagen types I and III in epineurium and similar immuno-positive area for staining of neurofilament and S-100beta. In contrast, we measured significantly different ratios of collagen type I to type III in the endoneurium. This combined analysis of the main tissue components of peripheral nerves could be an easy-to-use tool in evaluating changes during damage caused by scaring, systemic disease or compression syndromes. The calculated collagen type I/III ratio may serve as an objective diagnostic value for the description or as prognostic marker for therapeutic approaches in peripheral nerve pathology. However, in particular studies of collagen accumulation in nerves, species dependant differences have to be considered.

[Importance of abdominal compartment syndrome in Germany: a questionnaire].

BACKGROUND The abdominal compartment syndrome (ACS) is a life-threatening condition and may affect any critically ill patient. Little is known about the recognition and management of the ACS in Germany. METHODS A postal questionnaire was sent to departments of surgery and anesthesia of German hospitals with more than 450 beds. RESULTS From the 222 eligible hospitals a total of 113 replies were received. Most respondents (95%) indicated that the ACS plays a role in their clinical practice. Measurement of intra-abdominal pressure (IAP) is not performed by 26% while it is routinely done by 30%. Intra-abdominal pressure is mostly (94%) assessed via the bladder pressure. Of the respondents 41% measure IAP only in those patients thought likely to develop ACS. Risk factors of the ACS would lead to IAP monitoring in 10-23% of cases. The majority (86%) would require signs of organ dysfunction together with exceeding the IAD threshold in order to opt for a surgical decompression. The attitude towards the critical threshold (>20 mmHg or >25 mmhg) divided respondents into two groups of similar size (39% compared to 47%, respectively). CONCLUSIONS German anesthesiologists and surgeons are familiar with the ACS. However, about one-quarter never measure IAP and there is a considerable variance as to which patients are at risk to develop ACS and how often IAP should be measured in these patients. This could indicate a lack of acceptance or simply a persisting need for more data concerning the avoidance and treatment of the ACS.

Bedeutung des abdominellen Kompartmentsyndroms in Deutschland

BACKGROUND The abdominal compartment syndrome (ACS) is a life-threatening condition and may affect any critically ill patient. Little is known about the recognition and management of the ACS in Germany. METHODS A postal questionnaire was sent to departments of surgery and anesthesia of German hospitals with more than 450 beds. RESULTS From the 222 eligible hospitals a total of 113 replies were received. Most respondents (95%) indicated that the ACS plays a role in their clinical practice. Measurement of intra-abdominal pressure (IAP) is not performed by 26% while it is routinely done by 30%. Intra-abdominal pressure is mostly (94%) assessed via the bladder pressure. Of the respondents 41% measure IAP only in those patients thought likely to develop ACS. Risk factors of the ACS would lead to IAP monitoring in 10-23% of cases. The majority (86%) would require signs of organ dysfunction together with exceeding the IAD threshold in order to opt for a surgical decompression. The attitude towards the critical threshold (>20 mmHg or >25 mmhg) divided respondents into two groups of similar size (39% compared to 47%, respectively). CONCLUSIONS German anesthesiologists and surgeons are familiar with the ACS. However, about one-quarter never measure IAP and there is a considerable variance as to which patients are at risk to develop ACS and how often IAP should be measured in these patients. This could indicate a lack of acceptance or simply a persisting need for more data concerning the avoidance and treatment of the ACS.

Comet-Tail-Like Inflammatory Infiltrate to Polymer Filaments Develops in Tension-Free Conditions

Background: Mesh reinforcement in hiatal hernia repair becomes more frequent but is charged by complications such as erosion or stenosis of the oesophagus. These complications are accompanied by an intense inflammatory infiltrate around the polymer fibres. To characterize this effect, the response to polypropylene fibres in the absence of tension was examined. Methods: In rats, polypropylene sutures (USP size 1, 3-0 and 7-0) were placed in the subcutis of the abdominal wall without knot or tension. On postoperative days 3, 7 and 21, specimens were excised. The expressions of c-myc, β-catenin, Notch3, COX-2, CD68 and Ki-67 were measured by immunohistochemistry. Results: In the absence of tension, sutures were surrounded by a foreign body granuloma with an inflammatory infiltrate not encircling the fibre but forming almost symmetric comet-tail-like infiltrates on opposite sides. The expression of c-myc, β-catenin, Notch3, COX-2, CD68 and Ki-67 was significantly reduced over time in the comet tail, but not in the granuloma. Conclusions: Even in tension-free conditions, surgical sutures cause a foreign body response with infiltrates of inflammatory cells. This reaction is shaped like a comet tail, and its extension depends on the diameter of the used fibre. Therefore, for reduction of perifilamental infiltrates, not only absence of tension is required, but also a small-sized fibre textile.

Clinical evaluation of an air-capsule technique for the direct measurement of intra-abdominal pressure after elective abdominal surgery

BackgroundThe gold standard for assessment of intraabdominal pressure (IAP) is via intravesicular pressure measurement (IVP). This accepted technique has some inherent problems, e.g. indirectness. Aim of this clinical study was to assess direct IAP measurement using an air-capsule method (ACM) regarding complications risks and agreement with IVP in patients undergoing abdominal surgery.MethodsA prospective cohort study was performed in 30 patients undergoing elective colonic, hepatic, pancreatic and esophageal resection. For ACM a Probe 3 (Spiegelberg®, Germany) was placed on the greater omentum. It was passed through the abdominal wall paralleling routine drainages. To compare ACM with IVP t-testing was performed and mean difference as well as limits of agreement were calculated.ResultsACM did not lead to complications particularly with regard to organ lesion or surgical site infection. Mean insertion time of ACM was 4.4 days (min-max: 1–5 days). 168 pairwise measurements were made. Mean ACM value was 7.9 ± 2.7 mmHg while mean IVP was 8.4 ± 3.0 mmHg (n.s). Mean difference was 0.4 mmHg ± 2.2 mmHg. Limits of agreement were -4.1 mmHg to 5.1 mmHg.ConclusionUsing ACM, direct IAP measurement is feasible and uncomplicated. Associated with relatively low pressure ranges (<17 mmHg), results are comparable to bladder pressure measurement.

Foreign body reaction in vaginally eroded and noneroded polypropylene suburethral slings in the female: a case series

Introduction and hypothesisAim of this study was to investigate the pattern of the foreign body reaction of macroporous polypropylene mesh (MPPM) used in females for the treatment of stress urinary incontinence and to compare this pattern between eroded and noneroded tapes.MethodsTen explanted suburethral slings, five eroded and five noneroded, were examined immunohistochemically under light microscopy; the tissue reaction was compared between eroded and noneroded materials.ResultsEroded material showed a significantly higher accumulation of macrophages around the filaments of the mesh.ConclusionsThis is the first study comparing reaction around eroded and noneroded MPPMs and indicates a more intense tissue reaction around eroded mesh, when compared to noneroded material. More studies are needed to prove whether the detected foreign body reaction was the actual trigger for the erosion.

New technical approach for the repair of an abdominal wall defect after a transverse rectus abdominis myocutaneous flap: a case report

IntroductionBreast reconstruction with autologous tissue transfer is now a standard operation, but abnormalities of the abdominal wall contour represent a complication which has led surgeons to invent techniques to minimize the morbidity of the donor site.Case presentationWe report the case of a woman who had bilateral transverse rectus abdominis myocutaneous flap (TRAM-flap) breast reconstruction. The surgery led to the patient developing an enormous abdominal bulge that caused her disability in terms of abdominal wall and bowel function, pain and contour. In the absence of rectus muscle, the large defect was repaired using a combination of the abdominal wall component separation technique of Ramirez et al and additional mesh augmentation with a lightweight, large-pore polypropylene mesh (Ultrapro®).ConclusionThe procedure of Ramirez et al is helpful in achieving a tension-free closure of large defects in the anterior abdominal wall. The additional mesh augmentation allows reinforcement of the thinned lateral abdominal wall.

Experimental investigation of the elasticity of the human diaphragm

BackgroundTraumatic diaphragmatic ruptures affect mainly the left side. In an experimental study in human corpses we examined the stretch behaviour of the left and right diaphragmatic halves.MethodsIn a total of 8 male and 8 female corpses each diaphragmatic half was divided into 4 different segments. Each segments stretch behaviour was investigated. In steps of 2 N the stretch was increased up to 24 N.ResultsIn the female the left diaphragm showed a stronger elasticity compared to the right. Additionally the left diaphragm in females showed a higher elasticity in comparison to the left in males. Traumatic diaphragmatic ruptures affect mostly the central tendineous part or the junction between tendineous and muscular part of the diaphragmatic muscle. Accordingly we found a lower elasticity in these parts compared with the other diaphragmatic segments.ConclusionIn summary it can be said that albeit some restrictions we were able to determine the elasticity of different diaphragmatic segments quantitatively and reproduceably with our presented method. Thereby a comparison of results of different diaphragmatic segments as well as of both diaphragmatic halves and of both genders was possible

Direct intra-abdominal pressure monitoring via piezoresistive pressure measurement: a technical note

BackgroundPiezoresistive pressure measurement technique (PRM) has previously been applied for direct IAP measurement in a porcine model using two different devices. Aim of this clinical study was to assess both devices regarding complications, reliability and agreement with IVP in patients undergoing elective abdominal surgery.MethodsA prospective cohort study was performed in 20 patients randomly scheduled to receive PRM either by a Coach®-probe or an Accurate++®-probe (both MIPM, Mammendorf, Germany). Probes were placed on the greater omentum and passed through the abdominal wall paralleling routine drainages. PRM was compared with IVP measurement by t-testing and by calculating mean difference as well as limits of agreement (LA).ResultsThere were no probe related complications. Due to technical limitations, data could be collected in 3/10 patients with Coach® and in 7/10 patients with Accurate++®. Analysis was carried out only for Accurate++®. Mean values did not differ to mean IVP values. Mean difference to IVP was 0.1 ± 2.8 mmHg (LA: -5.5 to 5.6 mmHg).ConclusionDirect IAP measurement was clinically uneventful. Although results of Accurate++® were comparable to IVP, the device might be too fragile for IAP measurements in the clinical setting. Local ethical committee trial registration: EK2024

Risks for Pain-Neuropathic Pain: How Should We Handle the Nerves?

In hernia surgery, interest has been focused more and more on pain, a problem that remained underestimated because only relatively few patients seemed to be affected. Chronic pain evolves in a high percentage after surgery with the need to mobilize or even compress nerves [1]; however, after groin hernia repair, symptoms vary to a high degree [2]. Pain character is mostly neuropathic, but due to overlapping distribution areas it is not clearly related to certain nerves [3]. The neuropathic pain character is accompanied by an inflammatory pain for some time after operation, which is understandable, especially when a mesh was used and foreign material remains in the body.