Christophe Iselin

Mechanical Tension Controls Granulation Tissue Contractile Activity and Myofibroblast Differentiation

We have examined the role of mechanical tension in myofibroblast differentiation using two in vivo rat models. In the first model, granulation tissue was subjected to an increase in mechanical tension by splinting a full-thickness wound with a plastic frame. Myofibroblast features, such as stress fiber formation, expression of ED-A fibronectin and alpha-smooth muscle actin (alpha-SMA) appeared earlier in splinted than in unsplinted wounds. Myofibroblast marker expression decreased in control wounds starting at 10 days after wounding as expected, but persisted in splinted wounds. In the second model, granuloma pouches were induced by subcutaneous croton oil injection; pouches were either left intact or released from tension by evacuation of the exudate at 14 days. The expression of myofibroblast markers was reduced after tension release in the following sequence: F-actin (2 days), alpha-SMA (3 days), and ED-A fibronectin (5 days); cell density was not affected. In both models, isometric contraction of tissue strips was measured after stimulation with smooth muscle agonists. Contractility correlated always with the level of alpha-SMA expression, being high when granulation tissue had been subjected to tension and low when it had been relaxed. Our results support the assumption that mechanical tension is crucial for myofibroblast modulation and for the maintenance of their contractile activity.

The Higher Injury Risk of Abnormal Kidneys in Blunt Renal Trauma

Objective: To investigate the vulnerability of abnormal kidneys in blunt trauma, and to determine clinical features which enable identification of patients at risk of renal abnormality, hence modifying their management. Material and Methods: The medical records of 120 patients with blunt renal trauma were reviewed. Presence of pre-existing renal abnormalities, clinical symptoms, contrast study findings, associated injuries and the estimated impact velocity were recorded. Results: Pre-existing renal abnormalities were found in 23 patients (19%). Patients with renal abnormalities had a lower rate of associated trauma to other abdominal organs, a lower Injury Severity Score (ISS) and their kidneys were more frequently injured by low velocity impacts. Of the patients with normal kidneys requiring surgery, hemodynamics and/or severity of the renal lesions triggered the operative indications in all cases, whereas most (57%) of the abnormal kidneys were operated because of their underlying renal pathology. Concl...

Advances in the management of blunt traumatic bladder rupture: experience with 36 cases

Study Type – Therapy (case series)
Level of Evidence 4

Capsular Perforation Localization and Adenoma Size as Prognostic Indicators of Erectile Dysfunction after Transurethral Prostatectomy

The incidence of impotence following transurethral resection of the prostate (TURP) for benign prostatic hyperplasia (BPH) was investigated, as well as its correlation with the localization of peroperative capsular perforations and the amount of prostate tissue resected. Patients underwent an interview questioning their potency before and after TURP. For each patient, the TURP technique was reviewed: the localization of eventual capsular perforations was noted and the amount of tissue resected was recorded. Of the 100 patients assessed, 83 were anamnestically potent prior to TURP. Of these, 27 (##%) reported complete loss of erections after operation. Peroperative capsular perforations adjacent to the neurovascular bundles and small-size adenomas correlated significantly with postoperative impotence. The results suggest that capsular perforations adjacent to the neurovascular bundles may be a cause of impotence after TURP, and that patients with small-size adenomas bear a higher risk of post-TURP erectile dysfunction.

The nitric oxide synthase/nitric oxide and heme oxygenase/carbon monoxide pathways in the human ureter

Objective: To investigate the nitric oxide synthase (NOS)/nitric oxide (NO) and heme oxygenase (HO)/carbon monoxide (CO) pathways in the human isolated ureter. Methods: Immunohistochemical studies were performed. NOS activity was measured by monitoring the converison of [3H]-arginine to [3H]-citrulline. Functional inhibitory effects mediated by NO and CO were assessed, and correlated with cyclic nucleotide levels. Results: The overall innervation of the ureter was moderate, however more prominent in the distal segment. Relative to overall innervation, neuronal NOS-immunoreactive (-IR) nerves were few. In the submucosa, neuronal NOS-IR varicose nerves were found closely together with varicose nerves containing calcitonin gene-related peptide immunoreactivity. In the distal ureter, nerve trunks were demonstrated, expressing immunoreactivity for HO-2. Ca2+-dependent NOS activity was 53 ± 13 pM/mg protein/h. In isolated preparations, NO decreased endothelin-1-induced contractions in a concentration-dependent manner. In strips exposed to NO, there was a 6-fold increase of the cyclic GMP levels in comparison to control preparations (p < 0.001). CO exerted no effect on induced ureteral tone. Conclusions: Neuronal NOS- and HO-2-IR nerves can be demonstrated in the human ureter, where NO, but probably not CO, may contribute to the regulation of tone. Although the physiological roles for NO and CO remain to be established, the NOS/NO/cyclic GMP pathway may be a target for drugs producing relaxation of the human ureter. The richer innervation of the distal ureter may be of importance for the coordination of ureteral peristalsis and the motility of the ureterovesical junction.

Intestinal obstruction following use of laparoscopic barbed suture: A new complication with new material?

Abstract Small bowel obstruction is a common pathology. Among the various etiologies, foreign material has been incriminated as a possible but uncommon cause. Recently, barbed suture has been successfully introduced in various surgical fields and has been reported as safe as standard suture. We report herein a case of intestinal obstruction due to the laparoscopic use of barbed suture during a promontofixation. Barbed suture has the risk of entrapping the small bowel. The surgeon should keep in mind this hypothetical problem and a high index of suspicion is needed to diagnose and treat quickly this potentially severe complication.

Nitric Oxide Inhibits Contraction of Isolated Pig Ureteral Smooth Muscle

PURPOSE To investigate the L-arginine/nitric oxide (NO) pathway in the pig isolated ureter. MATERIALS AND METHODS Functional inhibitory effects mediated by NO were assessed and correlated with cyclic nucleotide levels. Nitric oxide synthase (NOS) activity was measured by monitoring the conversion of [3H]-arginine to [3H]-citrulline. Immunohistochemical studies were performed. RESULTS The NO-donor SIN-1 reduced in a concentration-dependent manner the frequency of contractions, whereas NO completely interrupted the contractile activity. In precontracted strips exposed to SIN-1 or NO, there were 6- and 12-fold increases of the cyclic GMP levels in comparison with control preparations. Activity of NOS was moderate. Overall innervation of the ureter was sparse, and there were few NOS-immunoreactive nerves. CONCLUSION Although few NOS-containing nerves were found, pathways regulating the cyclic GMP levels of pig ureteral smooth muscle were demonstrated. Such pathways may be important targets for drugs producing relaxation of the mammalian ureter.

Value of immunohistochemistry in staging T1 urothelial bladder carcinoma

PURPOSE The subclassification of T1 bladder tumors into T1A and T1B has an important prognostic significance and a great impact on patient management. Unfortunately, staging T1 tumors is highly subject to interpathologist variation that can be critical for patients included in randomized clinical trials. To determine the value of immunohistochemistry (IHC), such as desmin and keratin, in comparison to hematoxylin-eosin (H&E) in classifying T1 stage disease, we retrospectively examined 93 consecutive cases diagnosed at our department. MATERIALS AND METHODS The study was conducted in two phases (H&E then IHC), each in two time periods. First H&E, and then IHC slides were reviewed independently by two experienced pathologists and discrepant cases from each phase were discussed between the two pathologists to reach a final decision. RESULTS The two methodologies (H&E and IHC) showed total agreement in 76 out of 93 cases. IHC downstaged seven cases, that is from T1B to T1A, upstaged four cases, that is from T1A to T1B, lowered the rate of imprecision and eliminated the disagreement between the two pathologists. However, IHC failed to subclassify T1 tumors in three cases. Finally, the discussion supported by the IHC was very useful in reaching the diagnosis in some cases. CONCLUSIONS IHC appears to be a useful tool in staging T1 bladder cancer, especially in difficult cases where specimen orientation and artifact could create a major hindrance in reaching an accurate diagnosis.

Importance and determinants of Gleason score undergrading on biopsy sample of prostate cancer in a population-based study

BackgroundIn this population-based study, we investigated the degree of concordance between Gleason scores obtained from prostate biopsies and those obtained from prostatectomy specimens, as well as the determinants of biopsy understaging.MethodsWe considered for this study all 371 prostate cancer patients recorded at the Geneva Cancer Registry diagnosed from 2004 to 2006 who underwent a radical prostatectomy. We used the kappa statistic to evaluate the Gleason score concordance from biopsy and prostatectomy specimens. Logistic regression was used to determine the parameters that predict the undergrading of the Gleason score in prostate biopsies.ResultsThe kappa statistic between biopsy and prostatectomy Gleason score was 0.42 (p < 0.0001), with 67% of patients exactly matched, and 26% (n = 95) patients with Gleason score underestimated by the biopsy. In a multi-adjusted model, increasing age, advanced clinical stage, having less than ten biopsy cores, and longer delay between the two procedures, were all independently associated with biopsy undergrading. In particular, the proportion of exact match increased to 72% when the patients had ten or more needle biopsy cores. The main limitation of the study is that both biopsy and prostatectomy specimens were examined by different laboratories.ConclusionsThe data show that concordance between biopsy and prostatectomy Gleason scores lies within the classic clinical standards in this population-based study. The number of biopsy cores appears to strongly impact on the concordance between biopsy and radical prostatectomy Gleason score.

Percutaneous cryoablation of small kidney tumours under magnetic resonance imaging guidance: medium-term follow-up

Objective. Minimally invasive treatment of small kidney tumours remains a challenge. Cryoablation has recently been advocated for such neoplasias. However, few series evaluating this therapeutic regimen are as yet available. The goal of this retrospective study was to evaluate the initial clinical experience of magnetic resonance imaging (MRI)-guided percutaneous cryotherapy of small renal tumours. Material and methods. Seven patients with small renal tumours [mean diameter 21 (11–30) mm] underwent percutaneous renal tumour cryoablation using the Cryo-Hit® delivery system. The procedure was performed in an MRI interventional unit, using a 0.23 Tesla open MRI imaging system. Five men and two women were included in the group. The average age was 61.5 (34–84) years. The patients had a solitary kidney (n=2), renal insufficiency (n=4) or a kidney graft (n=1). The intervention was performed under general anaesthesia. Average time for the whole procedure was 235 min with 26 min of effective treatment time. Mean follow-up was 28 (7–43) months. Results. All tumours were successfully ablated. There were no perioperative complications. Mean hospital stay was 2.4 (2–5) days. One patient stayed for 5 days because therapeutic anticoagulation had to be reinitiated. No significant change in the perioperative value of the serum creatinine was noticed. No radiographic evidence of disease recurrence or new tumour development was identified during the follow-up. Conclusions. In this small group of patients, percutaneous renal tumour cryoablation under MRI guidance was efficient and carried no morbidity. Hospital stay was remarkably shorter than that of surgically treated patients. At medium-term follow-up, no recurrence has been identified, but long-term follow-up is required.