Preliminary Evaluation of a Blast Sprayer Controlled by Pulse-Width-Modulated Nozzles.

Precision spraying relies on the response of the spraying equipment to the features of the targeted canopy. PWM technology manages the flow rate using a set of electronically actuated solenoid valves to regulate flow rate at the nozzle level. Previous studies have found that PWM systems may deliver incorrect flow rates. The objective of the present study was to characterize the performance of a commercial blast sprayer modified with pulse-width-modulated nozzles under laboratory conditions, as a preliminary step before its further field validation. Four different duty cycles (25 percent, 50 percent, 75 percent and 100 percent) and four different pressures (400 kPa, 500 kPa, 600 kPa and 700 kPa) were combined to experimentally measure the flow rate of each nozzle. Results showed that the PWM nozzles mounted in the commercial blast sprayer, under static conditions, were capable of modulating flow rate according to the duty cycle. However, the reduction of flow rates for the tested duty cycles according to pressure was lower than the percentage expected. A good linear relation was found between the pressure registered by the control system feedback sensor and the pressure measured by a reference conventional manometer located after the pump. High-speed video recordings confirmed the accurate opening and closing of the nozzles according to the duty cycle; however, substantial pressure variations were found at nozzle level. Further research to establish the general suitability of PWM systems for regulating nozzle flow rates in blast sprayers without modifying the system pressure still remains to be addressed.

Predictors of hernia recurrence after Rives-Stoppa repair in the treatment of incisional hernias: a retrospective cohort.

BACKGROUND: Rives-Stoppa retromuscular repair (RSR) has been traditionally used to provide adequate coverage for large abdominal wall defects and appears to be more advantageous compared to other surgical techniques concerning complications and recurrence rates. The aim of this study was to identify the independent predictors associated to hernia recurrence after RSR in the treatment of incisional hernias. METHODS: This is a retrospective observational study of 213 patients who underwent RSR between June 2007 and January 2014 at a tertiary centre. Main inclusion criteria were adults with midline hernia classified as M1, M2, M3, M4, or M5, according to EHS classification. All the cases presented a transverse hernia defect measurement greater than 5 cm (grades W2 and W3). Recurrence rate was determined by clinical examination plus confirmation by abdominal CT scan. RESULTS: At a median of 57.6 months (range 46-75 months) of postoperative follow-up, we reported 15 cases of recurrence (7.1%). Recurrences occurred after a mean period of 19.4 months (range 2-49 months). On multivariate analysis, steroid or immunosuppressive drugs use (OR 2.02; CI 1.16-3.95, p = 0.004), the development of postoperative hematoma (OR 2.9; CI 1.55-4.10, p = 0.001), and needing surgery for the hematoma (OR 2.1; CI 1.21-3.29, p = 0.004) were predictors of recurrence after RSR. There was no significant difference in recurrence rate among obesity, smoking, urgent repair, type of mesh fixation, operative time, type of prosthesis, or concomitant procedures. CONCLUSIONS: In our current study, using immunosuppressive drugs, the development of postoperative hematoma and needing surgery for the hematoma were associated with increased risk of hernia recurrence after RSR.

Preoperative combination of progressive pneumoperitoneum and botulinum toxin type A in patients with loss of domain hernia.

INTRODUCTION: Preoperative progressive pneumoperitoneum (PPP) and botulinum toxin type A (BT) are tools in the surgical preparation of patients with loss of domain hernias (LODH). The aim of this paper is to report our experience with these preoperative techniques in 70 patients with LODH. METHODS: Observational study of 70 consecutive patients with LODH was conducted between May 2010 and May 2016. Diameters of the hernia sac, incisional hernia (VIH), and abdominal cavity (VAC) volumes, and VIH/VAC ratio were measured before and after PPP and BT, using abdominal CT scan data. Combination of both techniques was performed when the VIH/VAC ratio was > 20%. RESULTS: Median insufflated volume of air for PPP was 8450 ± 3400 cc (4500-13,450), over a period of 11.3 ± 2.3 days (9-16). BT administration time was 38.1 ± 3.7 days (35-44). An average reduction of 16.6% of the VIH/VAC ratio after PPP and BT was obtained (p < 0.05). Complications associated with PPP were 20%, and with surgical technique 29.6%. No complications occurred during the BT administration. Reconstructive technique was anterior CST in 54 patients, TAR in 14 cases and Rives-Stoppa technique in two patients. Median follow-up was 34.5 ± 22.3 months (12-60) and four cases of hernia recurrence (5.7%) were reported. CONCLUSIONS: Using a CT volumetric protocol, combination of PPP and BT decreases the VIH/VAC ratio and hernia defect diameters, which constitutes a key factor in the treatment of LODH.

Progrip self-gripping mesh in Rives-Stoppa repair: Are there any differences in outcomes versus a retromuscular polypropylene mesh fixed with sutures? A "case series" study.

BACKGROUND: Rives-Stoppa repair is widely accepted technique in large midline IH, and appears to be advantageous compared to other surgical techniques concerning complications and recurrence rates. The aim of this case series study was to analyze 1-year outcomes in patients with IH treated with Progrip self-gripping mesh compared to polypropylene (PPL) mesh fixed with sutures during the Rives-Stoppa technique. METHODS: Between June 2014 and June 2015, we performed a prospective comparative non-randomized (case series) analysis between 25 patients with IH using retromuscular Progrip self-gripping mesh and 25 patients with retromuscular PPL mesh fixed with sutures, under Rives-Stoppa repair. All intraoperative and perioperative morbidities were reported with particular attention to wound infection, seroma or hematoma formation, duration of hospital stay, presence of abdominal wall pain (VAS) and recurrence during long-term follow-up. RESULTS: Mean operative time in Progrip group was shorter than Non-Progrip group (101±29.5 versus 121±39.8min). In Progrip group, the only postoperative complication was seroma in two patients; however, in Non-Progrip group, we reported seroma in three patients, and hematoma in 4 patients (p=0.03). The median hospital stay was shorter in Progrip group (5.8±2.2days versus 6.6±2.9days). Mean VAS score in the first 48h was higher in Non-Progrip group than Progrip group (4.9±2.1 versus 8.1±2)(p=0.01). The median follow-up was 13 months (range 12-20 months) and none of the 50 patients had a hernia recurrence. CONCLUSIONS: In Rives-Stoppa repair, retromuscular Progrip mesh causes less postoperative pain in the first 48h and lower rate of hematoma than PPL mesh fixed with sutures in the short term follow-up.

Update on the diagnosis and treatment of mirizzi syndrome in laparoscopic era: our experience in 7 years.

INTRODUCTION: Mirizzi syndrome (MS) is a rare complication of cholelithiasis. The objective of this study was to assess the current incidence of MS in our area and present our experience in the clinical, diagnostic, and therapeutic management, focussing in laparoscopic approach. MATERIALS AND METHODS: We prospectively analyzed 35 cases of MS between January 2006 and November 2012, collecting information regarding demographics, clinical management, diagnostic methods, surgical procedure, postoperative morbidity, and follow-up. All patients underwent abdominal ultrasonography. In patients with suspected obstructive jaundice, magnetic cholangiography resonance and endoscopic retrograde cholangiopancreatogram were performed preoperatively, detecting MS in 68.5% of patients. RESULTS: The incidence of MS was 2.8% in 1168 cholecystectomies for cholelithiasis. There were 13 men and 22 women, with a mean age of 70.1 years. Nineteen patients had MS type I (54.2%). Fourteen were treated with laparoscopic cholecystectomy (LC) successfully, whereas 3 conversions were performed because of difficult surgical dissection. In the remaining 2, subtotal cholecystectomy was performed. Seven patients had type II MS (20%). In 5 cases cholecystectomy and bile duct repair were performed with T-tube placement (in 4 by laparoscopic approach), in another one subtotal cholecystectomy with primary biliary choledochorrhaphy was performed, because of dilated bile duct. Finally, the remaining patients with type III and IV SM (14.2% and 11.4%, respectively) were treated with Roux-en-Y hepaticojejunostomy.We observed 14.5% morbidity, highlighting 2 cases of postoperative collection and 1 case of biliary fistula. There was no postoperative mortality. The mean follow-up of patients was 13.4±4 months. CONCLUSIONS: Preoperative diagnosis of MS is difficult, but it is essential in the proper management of the disease. Investigations as magnetic cholangiography resonance and endoscopic retrograde cholangiopancreatogram contribute to the success of preoperative identification. LC should be reserved to MS type I and type II highly selected cases. This pathology should be treated by experienced surgeons to decrease the risk of iatrogenia.

Técnica de Kugel: abordaje preperitoneal para el tratamiento de la hernia inguinal. Resultados preliminares / Kugel's Technique: preperitoneal approach for the treatment of inguinal hernia. Preliminary results

Introducción. El objetivo del presente trabajo es presentar los resultados preliminares de la reparación herniaria inguinal mediante una nueva malla protésica de polipropileno, a través de un abordaje preperitoneal siguiendo la técnica descrita por Kugel. Pacientes y método. Se estudia prospectivamente a 27 pacientes tratados de 30 hernias inguinales (4 directas, 24 oblicuas externas y dos mixtas), de las que tres eran bilaterales, mediante esta técnica entre abril y junio de 2000. Se comentan los aspectos técnicos del procedimiento. Resultados. Aunque el período de seguimiento es corto (entre 4 y 6 meses), se ha observado una única incidencia: seroma (3,7 por ciento), que se drenó y sólo requirió curas locales durante 7 días. No se han presentado otras complicaciones ni recidivas hasta la fecha. Conclusiones. Con el abordaje mínimamente invasivo y prácticamente sin suturas de esta técnica, que puede realizarse con anestesia local o regional, y el uso de esta nueva malla se obtienen unos resultados excelentes que se deben validar a más largo plazo, aunque pensamos que es una buena técnica que debería incorporarse a nuestro armamentarium quirúrgico y que debemos conocer (AU)