Allogeneic limbo-deep anterior lamellar keratoplasty (Limbo-DALK)—A novel surgical technique in corneal stromal disease and limbal stem cell deficiency

by Verena Schöneberger, Volkan Tahmaz, Mario Matthaei, Sigrid Roters, Simona L. Schlereth, Friederike Schaub, Claus Cursiefen, Björn O. Bachmann

To describe a novel corneal surgical technique combining Deep Anterior Lamellar Keratoplasty (DALK) with grafting of allogeneic limbus (Limbo-DALK) for the treatment of eyes with corneal stromal pathology and limbal stem cell deficiency (LSCD).

Clinical records of six Limbo-DALKs performed in five patients diagnosed with LSCD and corneal stromal pathology requiring keratoplasty were retrospectively reviewed. All patients were diagnosed with LSCD due to various pathologies including thermal and chemical burns, congenital aniridia or chronic inflammatory ocular surface disease. Parameters analysed included demographics, diagnoses, clinical history, thickness measurements using anterior segment OCT, visual acuity, and epithelial status. Regular follow-up visits were scheduled at 6 weeks as well as 3, 6, 9, and 12 and 18 months postoperatively. Main outcome measures were time to graft epithelialisation and the occurrence of corneal endothelial decompensation.

Two grafts showed complete epithelial closure at 2 days, two at 14 days. In one eye, complete epithelial closure was not achieved after the first Limbo-DALK, but was achieved one month after the second Limbo-DALK. No endothelial decompensation occurred except in one patient with silicone oil associated keratopathy. Endothelial graft rejection was not observed in any of the grafts.

Based on the data from this pilot series, limbo-DALK appears to be a viable surgical approach for eyes with severe LSCD and corneal stromal pathology, suitable for emergency situations (e.g. corneal ulceration with impending corneal perforation), while minimising the risk of corneal endothelial decompensation.

The role of muscle degeneration and spinal balance in the pathophysiology of lumbar spinal stenosis: Study protocol of a translational approach combining in vivo biomechanical experiments with clinical and radiological parameters

by David Koch, Corina Nüesch, Dominika Ignasiak, Soheila Aghlmandi, Alice Caimi, Guido Perrot, Friederike Prüfer, Dorothee Harder, Francesco Santini, Stefan Schären, Stephen Ferguson, Annegret Mündermann, Cordula Netzer

To describe a study protocol for investigating the functional association between posture, spinal balance, ambulatory biomechanics, paraspinal muscle fatigue, paraspinal muscle quality and symptoms in patients with symptomatic lumbar spinal stenosis (sLSS) before and 1-year after elective surgical intervention.

Single-centre prospective, experimental, multimodal (clinical, biomechanical, radiological) study with three instances of data collection: baseline (study visit 1), 6-month follow-up (remote) and 1-year follow-up (study visit 2). Both study visits include an in vivo experiment aiming to elicit paraspinal muscle fatigue for postural assessment in a non-fatigued and fatigued state.

At baseline and 1-year follow-up, 122 patients with sLSS will be assessed clinically, perform the back-performance scale assessment and complete several patient-reported outcome measure (PROMs) questionnaires regarding overall health, disease-related symptoms and kinesiophobia. Posture and biomechanical parameters (joint kinematics, kinetics, surface electromyography, back curvature) will be recorded using an optoelectronic system and retroreflective markers during different tasks including overground walking and movement assessments before and after a modified Biering-Sørensen test, used to elicit paraspinal muscle fatigue. Measurements of muscle size and quality and the severity of spinal stenosis will be obtained using magnetic resonance imaging (MRI) and sagittal postural alignment data from EOS radiographies. After each study visit, physical activity level will be assessed during 9 days using a wrist-worn activity monitor. In addition, physical activity level and PROMs will be assessed remotely at 6-month follow-up.

The multimodal set of data obtained using the study protocol described in this paper will help to expand our current knowledge on the pathophysiology, biomechanics, and treatment outcome of degenerative sLSS. The results of this study may contribute to defining and/or altering patient treatment norms, surgery indication criteria and post-surgery rehabilitation schedules.

The protocol was approved by the regional ethics committee and has been registered at clinicaltrials.gov (NCT05523388).

Severe necrotizing soft tissue infections—Is wound microbiology a prognostic factor for clinical outcome?

Abstract

Necrotizing soft tissue infections (NSTIs) represent similar pathophysiological features, but the clinical course might range from subacute to a rapidly progressive, fulminant sepsis. Initial wound microbiology is the base for the Guiliano classification. The timeline of microbiological colonization has not been described during the clinical course. The role of the different microbiological pathogens on the outcome and mortality is unclear. One hundred eighty patients were included with septic inflammation response syndrome on admission. Initial wound microbiology and the changes in wound microbiology were analysed during the clinical course and correlated with outcome and risk indicators. Overall mortality was 35%. Higher age, a high Charlson Comorbidity Index or ASA score and truncal infections were highly prognostic for a lethal outcome. Microbiological findings revealed significant differences in the persistence of bacteria during the course of disease. Streptococci were only detectable within the first 5 days, whereas other bacteria persisted over a longer period of time. Initial microbiological findings correlated with better prognosis when no causative agent was identified and for gram-negative rods. Varying survival rates were observed for different Streptococci, Staphylococci, Enterococci and other bacteria. The highest odds ratio for a lethal outcome was observed for Enterococci and fungi. Microbiological colonization changes during the clinical course of NSTIs and some microbiologic pathogens are predictive for worsening the outcome and survival. Streptococcus pyogenes is only detectable in the very early phase of NSTI and after 6 days not anymore detectable. Later Enterococci and fungi showed the highest odds ratios for a lethal outcome. Enterococci bacteria and fungi have yet not been considered of clinical relevance in NSTI or even as indicator for worsening the outcome.