Does the angle of trocar insertion affect the fascial defect caused? A porcine model

INTRODUCTION

With an incidence of 0-5.2%, trocar site hernias frequently occur following laparoscopy. It is unclear to what extent the angle of trocar insertion affects the size of the fascial defect caused. Hence, we performed a porcine model.

METHODS

In October 2022, a total of five female pigs were euthanized. In alternating order, three bladeless and two bladed conical 12-mm trocars were inserted at an angle of 45° on each side for 60 min twice each pig. For this purpose, an epoxy resin handmade cuboid with a central channel that runs at an angle of 45° was used. Subsequently, photo imaging and defect size measurement took place. The results were compared with those of our previously conducted and published porcine model, in which the trocars were inserted at an angle of 90°. Effects of trocar type (bladed vs. bladeless) and angle on defect size were analyzed using a mixed model regression analysis.

RESULTS

The bladeless trocars caused statistically significant smaller defects at the fascia than the bladed (23.4 (SD = 16.9) mm2 vs. 41.3 (SD = 14.8) mm2, p < 0.001). The bladeless VersaOne trocar caused the smallest defect of 16.0 (SD = 6.1) mm2. The bladed VersaOne trocar caused the largest defect of 47.7 (SD = 10.5) mm2. The defect size of the trocars used at a 45° angle averaged 30.5 (SD = 18.3) mm2. The defect size of trocars used at a 90° angle was significantly larger, averaging 58.3 (SD = 20.2) mm2 (p = 0.007).

CONCLUSION

When conical 12-mm trocars are inserted at a 45° angle, especially bladeless ones, they appear to cause small fascial defects compared with insertion at a 90° angle. This might lead also to a lower rate of trocar hernias. Bladeless trocars might cause smaller fascial defects than bladed trocars.

How often is prophylactic parastomal mesh placement performed after rectal resection without sphincter preservation? An analysis of German nationwide hospital discharge data among 41,697 patients

PURPOSE

The European Hernia Society guidelines of parastomal hernias, published in 2017, strongly recommend prophylactic synthetic non-absorbable mesh upon the construction of a permanent end colostomy to reduce the incidence of parastomal hernias. This study aims to evaluate the implementation of the guidelines in Germany.

METHODS

This is a retrospective multicentric analysis conducted in December 2022 at the University Hospital Brandenburg an der Havel. Anonymous data on rectal resection without sphincter preservation in the period 2010-2020 were extracted from the German nationwide hospital discharge data set. Individuals with a hernia and < 18 years old were excluded. Another exclusion criterion was a performed colectomy or proctocolectomy with an ileoanal pouch and placement of an absorbable mesh. The primary endpoint was the annual rate of prophylactic parastomal mesh placement following rectal resection without sphincter preservation in Germany. Cases reporting both non-absorbable mesh placement and rectal resection without sphincter preservation were considered prophylactic mesh insertions.

RESULTS

A total of 41,697 patients received a rectal resection without sphincter preservation and without non-absorbable mesh placement. Among these individuals, 27,089 were male and 14,608 were female. The rate of reoperations (3.1%) and the length of hospital stay (25.3 days ± 19.32) remained almost constant during these 10 years. The rate of prophylactic mesh placement was increasing from 0.2% (n = 8) in 2010 to 6.4% (n = 198) in 2020.

CONCLUSIONS

Currently, only the minority of patients who have undergone rectal resection without sphincter preservation receive prophylactic mesh insertion.

The effect of an abdominal binder on postoperative outcome after open incisional hernia repair in sublay technique: a multicenter, randomized pilot trial (ABIHR-II)

INTRODUCTION

Although the evidence is minimal, an abdominal binder is commonly prescribed after open incisional hernia repair (IHR) to reduce pain. This study aimed to investigate this common postoperative treatment.

METHODS

The ABIHR-II trial was a national prospective, randomized, multicenter non-AMG/MPG pilot study with two groups of patients (wearing an abdominal binder (AB) for 2 weeks during daytime vs. not wearing an AB following open IHR with the sublay technique). Patient enrollment took place from July 2020 to February 2022. The primary endpoint was pain at rest on the 14th postoperative day (POD) using the visual analog scale (VAS). The use of analgesics was not systematically recorded. Mixed-effects linear regression models were used.

RESULTS

A total of 51 individuals were recruited (25 women, 26 men; mean age 61.4 years; mean body mass index 30.65 kg/m2). The per-protocol analysis included 40 cases (AB group, n = 21; No-AB group, n = 19). Neither group showed a significant difference in terms of pain at rest, limited mobility, general well-being, and seroma formation and rate. Patients among the AB group had a significantly lower rate of surgical site infection (SSI) on the 14th POD (AB group 4.8% (n = 1) vs. No-AB group 27.8% (n = 5), p = 0.004).

CONCLUSION

Wearing an AB did not have an impact on pain and seroma formation rate but it may reduce the rate of postoperative SSI within the first 14 days after surgery. Further trials are mandatory to confirm these findings.

[Epidemiology and surgical treatment of pancreatic cancer in the State of Brandenburg : Analysis of 5418 cases]

BACKGROUND

Pancreatic cancer is the second most frequent cause of death among all forms of cancer in Germany with more than 19,000 deaths per year. The evaluation of the nationwide clinical cancer register aims to depict the reality of treatment and to improve the quality of treatment in the future by targeted analyses.

METHOD

The data from the clinical cancer register of Brandenburg-Berlin for the diagnosis years 2001-2017 were analyzed with respect to the treatment of pancreatic cancer. Data from patients resident in the State of Brandenburg were evaluated with respect to epidemiological and therapeutic parameters.

RESULTS

A total of 5418 patients with pancreatic cancer were documented in the register from 2001 to 2017 and 49.6% of the patients were diagnosed as having the Union for International Cancer Control (UICC) stage IV. A pancreas resection was carried out in 26.4% of the cases. In cases of cancer of the head of the pancreas the most frequent procedure was a pylorus-preserving resection with 51.8% and a pancreatectomy was carried out in 9.4%. The R0 resection rate of all pancreatic cancers in the period from 2014 to 2017 was 61.9%. After R0 resection the 5‑year survival was 19%. Relevant multivariate survival factors were age, UICC stage and the residual (R) tumor classification. The case numbers per hospital had no influence on the absolute survival of patients operated on in the State of Brandenburg.

CONCLUSION

The treatment reality in the State of Brandenburg for patients with pancreatic cancer corresponds to the results of international publications with respect to the key performance indicators investigated. A qualitative internationally comparable treatment of these patients is also possible in nonmetropolitan regions.

[Pathogenesis of hidradenitis suppurativa/acne inversa]

Hidradenitis suppurativa/acne inversa (HS) has a multifactorial pathogenesis. In addition to a sporadic form, a familial form is reported in around 40% of patients, for whom an autosomal dominant (AD) inheritance with reduced gene penetrance is assumed. The phenotype of the disease with inflammatory nodules, abscesses and secreting sinus tracts suggests an infectious origin, but the exact role of the bacteria detected in HS pathogenesis remains unclear. Smoking and metabolic syndrome are regarded as important trigger factors in HS, with obesity and hormonal changes playing a pathogenic role in the latter. Ultimately, Toll-like receptors, antimicrobial peptides, immune cells and key cytokines are involved in the excessive inflammatory reaction of HS and are also the targets of future therapies.

[Triclosan-coated sutures in colorectal surgery : Assessment and meta-analysis of the recommendations of the WHO guideline]

BACKGROUND

In the global guidelines for the prevention of surgical site infections (SSI), the World Health Organization (WHO) recommends the general use of triclosan-coated sutures irrespective of the type of surgical intervention.

OBJECTIVE

Can this recommendation on the use of triclosan-coated sutures be confirmed by a meta-analysis specifically for colorectal surgery?

METHODS

Randomized and non-randomized clinical trials comparing triclosan-coated and uncoated sutures for the efficacy in reducing the SSI rate in colorectal surgery were identified by a systematic literature review. In addition, various quality criteria were set for the studies to be included: SSI definition according to the Centers for Disease Control and Prevention (CDC), a priori sample size calculation and a maximum SSI rate of 20%. The odds ratios were pooled using a fixed and random effects model, the 95% confidence intervals (CI) were calculated and subgroup analyses were carried out.

RESULTS

Included in the meta-analysis were 3 prospective randomized trials (RCT) and 3 non-randomized trials involving a total of 2957 subjects. The average SSI rate was 6.90% (76/1101) in the triclosan group and 9.11% (169/1856) in the control group, resulting in an odds ratio of 0.62 (95% CI: 0.29-1.31). Subgroup analysis showed a decreased risk for SSI in monocentric trials (OR = 0.39, 95% CI: 0.25-0.60) but an increased SSI risk in multicenter trials (OR = 1.75, 95% CI: 1.11-2.77).

CONCLUSION

Against the background of a moderate to high risk of bias and the partially contradictory findings of the studies, the general recommendation of the WHO on the use of triclosan-coated sutures for colorectal surgery could not be confirmed.

[Swiss clinical practice guidelines for skin cancer in organ transplant recipients]

Swiss clinical practice guidelines for skin cancer in organ transplant recipients Transplant patients have increased over the last decades. As a consequence of long-term immunosuppression, skin cancer, in particular squamous cell carcinoma (SCC), has become an important problem. Screening and education of potential organ transplant recipients (OTRs) regarding prevention of sun damage and early recognition of skin cancer are important before transplantation. Once transplanted, OTRs should be seen yearly by a dermatologist to ensure compliance with sun avoidance as well as for treatment of precancerosis and SCC. Early removal is the best treatment for SCC. Reduction of immunosuppression, switch to mTOR inhibitors and chemoprevention with acitretin may reduce the incidence of SCC. The dermatological follow-up of OTRs should be integrated into a comprehensive post-transplant management strategy.

Vibrational and electronic characterization of ethynyl derivatives grafted onto hydrogenated Si(111) surfaces

Covalent grafting of ethynyl derivatives (-C triple bond C-H, -C triple bond C-CH3, -C triple bond C-aryl) onto H-terminated Si(111) surfaces was performed by a one-step anodic treatment in Grignard electrolytes. The electrochemical grafting of such ethynyl derivatives, which tends to form ultrathin polymeric layers, can be controlled by the current and charge flow passing through the Si electrode. The prepared ultrathin layers cover the Si surface and had a thickness up to 20 nm, as investigated by the scanning electron microscopy (SEM) technique. Exchanging Cl for Br in the ethynyl Grignard reagent leads to very thin layers, even under the same electrochemical conditions. However, for all ethynyl derivatives, high-resolution synchrotron X-ray photoelectron spectroscopy (SXPS) investigations reveal the incorporation of halogen atoms in the organic layers obtained. Moreover, it was observed that the larger the end group of the ethynyl derivative, the thinner the thickness of the ultrathin polymeric layers as measured by both SXPS and SEM techniques after low and high current flow respectively. For the first time, these new types of ultrathin organic layers on Si surfaces were investigated using infrared spectroscopic ellipsometry (IRSE). The different possible reaction pathways are discussed.

Swiss clinical practice guidelines for skin cancer in organ transplant recipients

Patients with a solid organ transplant have increased in numbers and in individual survival in Switzerland over the last decades. As a consequence of long-term immunosuppression, skin cancer in solid organ recipients (SOTRs) has been recognized as an important problem. Screening and education of potential SOTRs about prevention of sun damage and early recognition of skin cancer are important before transplantation. Once transplanted, SOTRs should be seen by a dermatologist yearly for repeat education as well as early diagnosis, prevention and treatment of skin cancer. Squamous cell carcinoma of the skin (SCC) is the most frequent cancer in the setting of long-term immunosuppression. Sun protection by behaviour, clothing and daily sun screen application is the most effective prevention. Cumulative sun damage results in field cancerisation with numerous in-situ SCC such as actinic keratosis and Bowen's disease which should be treated proactively. Invasive SCC is cured by complete surgical excision. Early removal is the best precaution against potential metastases of SCC. Reduction of immunosuppression and switch to mTOR inhibitors and potentially, mycophenolate, may reduce the incidence of further SCC. Chemoprevention with the retinoid acitretin reduces the recurrence rate of SCC. The dermatological follow-up of SOTRs should be integrated into the comprehensive post-transplant care.

Time-Resolved Synchrotron XPS Monitoring of Irradiation-Induced Nitrobenzene Reduction for Chemical Lithography

The irradiation-induced reduction of electrochemically grafted nitrobenzene films on Si(111) was monitored by high-resolution photoelectron spectroscopy. The experiments were performed using synchrotron soft X-ray irradiation at the BESSY II synchrotron facility. The evolution of different chemical species was monitored as a function of time. Careful fitting of the Si2p, C1s, N1s, and O1s core level spectra allowed us to follow this process in detail and to determine the constants of growth and decay of the specific components. The chemical changes were caused by the X-ray irradiation-induced secondary electron current through the aryl layer. A minor fraction (approximately 25%) of the initial nitro groups was split off and desorbed. The bulk of the NO2 groups was reduced to species in an amino-like chemical environment. A desorption of carbon fragments was not observed, and benzene ring specific shakeup satellites indicated that the aromatic ring structure remained intact. Irradiation-induced line-shape changes suggest a polymerization via -NH- bridges, which were formed after the irradiation-induced N-O bond splitting. A significant part of the released oxygen appeared to contribute to an oxidation of the silicon substrate at the Si(111)/benzene interface. The irradiation-induced aryl layer modification can be exploited for chemical lithography (i.e., a lateral structuring of functionalized silicon surfaces).

Effects of UV irradiation with one minimal erythema dose on human afferent skin lymph in vivo

Ultraviolet (UV) irradiation of the skin induces complex local and systemic immunomodulatory reactions. The biological effects of UV irradiation on human skin derived afferent lymph however are unknown. The aim of this study was to examine the effects of a single combined UV-A and UV-B irradiation with 1 minimal erythema dose (MED) on human skin derived lymph in vivo. After cannulation of a superficial lymph vessel on the lower leg, lymph flow and cell output per hour were determined before and for 6 days after UV irradiation of the lymph draining skin area in 5 volunteers. Furthermore, expression of CD1a, CD4, CD8, CD28, CD54, CD80, CD86 and HLA-DR on migrating lymph cells and cytokine levels (IL-1alpha, IL-1beta, IL-2, IL-6, IL-8, IL-10, IL-13, TNF-alpha and IFN-gamma) in the afferent lymph were analyzed by cytofluorometry and ELISA. After UV irradiation a small initial enhancement in the daily lymph flow per hour was noticed in correlation with the slight erythematous skin reaction. Following resolution of the skin reaction, a delayed increase in cell output in correlation with an additional peak in the lymph flow was found between the 4th and 6th day after UV irradiation. However, no changes in the expression of CD1a, CD4, CD8, CD28, CD54, CD80, CD86 and HLA-DR on migrating lymph cells were detectable. Interestingly, in parallel to the increased lymph flow and cell output, only elevated IL-8 protein levels were reproducibly detected in the afferent lymph after UV irradiation. Furthermore, using immunohistochemistry positive staining for IL-8 was found on migrating mononuclear lymph cells. In conclusion, our data demonstrate that a single UV irradiation of the skin with 1 minimal erythema dose leads to a delayed enhancement of lymph flow, number of migrating lymph cells and cytokine levels of IL-8. Moreover, we provide evidence that migrating lymph cells, besides resident epidermal and dermal cells, may contribute to the detected levels of IL-8 in the afferent lymph.

Expression of interleukin-12 is increased in psoriatic skin

Although the precise underlying pathomechanisms of psoriasis have not been fully elucidated, previous reports suggest that T helper 1-type cytokines are critically involved in the pathogenesis of this disease. Interleukin-12 (IL-12), a heterodimeric cytokine, has been suggested to play a major role in the development of T helper 1 cell responses. In this study, the presence of IL-12 mRNA and protein was investigated in normal human skin as well as nonlesional and lesional psoriatic skin. Messenger RNA levels were determined in biopsy specimens by a standard and a nested reverse transcriptase-polymerase chain reaction method. Additionally, IL-12 protein expression was analyzed in situ by immunohistochemistry using an antibody recognizing IL-12 p70. Whereas specific transcripts for IL-12 p35 were reproducibly detected without any significant differences in all samples, enhanced IL-12 p40 mRNA signals were only found in lesional psoriatic skin as compared with normal and nonlesional psoriatic skin. Furthermore, immunoreactivity for IL-12 p70 was markedly increased in the psoriatic skin lesions and was predominantly expressed on mononuclear cells in the dermis. In conclusion, our data suggest a critical role for IL-12 in promoting and maintaining T cell activation and inducing T helper 1-type cytokines such as interferon-gamma in psoriasis. We speculate that IL-12 might be a key cytokine in the pathogenesis of psoriasis.