Surgery Research Articles

Z-shaped incision without epithelial resection in pterygium surgery

AIM: To introduce a novel surgical technique using a Z-shaped incision without epithelial resection in ophthalmic pterygia. METHODS: This was a prospective study. During pterygium surgery, all proliferative tissues were separated from the cornea and conjunctiva without resection of the tissues. The unaffected conjunctiva was incised in a Z-shape. The upper (or lower) conjunctival flap was sutured to the lower (or upper) normal conjunctiva on the limbal sclera, while the proliferative tissue was sutured to the upper conjunctiva (or lower) near the fornix. RESULTS: Ten patients with pterygia were eligible for this study. Eight patients with primary pterygia and 2 with recurrent pterygia were included. The age of patients at surgery ranged from 47 to 90y (average: 71.9y). Five patients each showed right and left-sided pterygia. The postoperative follow-up periods were from 8 to 78mo (average: 25.0mo). The surgery was successfully conducted and wounds were favorably reconstructed in all patients. The proliferative tissues sutured to the normal conjunctiva showed palor and attenuated neovessles, and never showed re-growth after surgery. Nine patients did not show recerrence. Recerrent pterygium was noted in 1 patient, but additional treatments were not required. CONCLUSION: The procedure involves the reconstruction of pterygial tissue and normal conjunctiva using a Z-shaped incision. The scleral limbal wound can be covered with non-affected conjunctiva without any excision of conjunctival epithelia in patients with primary or recurrent pterygia.

Reducing recurrence rates in hiatal hernia repair: Results of a quality improvement study.

Patient and procedure factors are considered in the decision-making process for surgical repair of hiatal hernias. Recurrence is multi-factorial and has been shown to be related to size, type, BMI and age. This study examined recurrence rates in a single institution, identified areas for improved surgical technique, and re-assessed recurrence following implantation of a quality improvement initiative. A retrospective review of patients undergoing hiatal hernia repair surgery between 2018 and 2022 was conducted. Demographics, pre-operative characteristics, intra-operative procedures and recurrence rates were reviewed. Seventy-five patients from 2018 to 2020 and 34 patients from 2021 to 2022 were identified. The recurrence rate was 21% in 2018-2020, with 14% requiring a revisional procedure. Recurrence and re-operation were subsequently reduced to 6% in 2021 and 2022, which was statistically significant (p = 0.043). There was an increase in gastropexy from 21% to 41% following the review (p = 0.032), which wasmainly reserved for large and giant hernias. Procedural and literature review, alongside gastropexy, can be attributed to recurrence rate reduction. It is important to educate patients on the likelihood and risk factors of recurrence. A comprehensive review of procedures and a quality improvement program in our facility for hiatal hernia repair is shown to reduce recurrence.

Comparative analysis of surgical techniques in the management of chronic subdural hematomas and risk factors for poor outcomes.

Comparative analysis of surgical techniques in the management of chronic subdural hematomas and risk factors for poor outcomes.

Early laparoscopic cholecystectomy in acute mild gallstone pancreatitis. Is there a role for routine admission contrast-enhanced CT Scan?

This study aims to evaluate the efficacy of admission contrast-enhanced CT scans in formulating strategies for performing early laparoscopic cholecystectomy in cases of acute gallstone pancreatitis. Patients diagnosed with acute gallstone pancreatitis underwent a CT scan upon admission (after at least 24h from symptom onset) to confirm diagnosis and assess peripancreatic fluid, collections, gallstones, and common bile duct stones. Patients with mild acute gallstone pancreatitis, following the Atlanta classification and Baltazar score A or B, were identified as candidates for early cholecystectomy (within 72h of admission). Within the analyzed period, 272 patients were diagnosed with mild acute gallstone pancreatitis according to the Atlanta Guidelines. A total of 33 patients (12.1%) were excluded: 17 (6.25%) due to SIRS, 10 (3.6%) due to local complications identified in CT (Balthazar D/E), and 6 (2.2%) due to severe comorbidities. Enhanced CT scans accurately detected gallstones, common bile duct stones, pancreatic enlargement, inflammation, pancreatic collections, and peripancreatic fluid. Among the cohort, 239 patients were selected for early laparoscopic cholecystectomy. Routine intraoperative cholangiogram was conducted in all cases, and where choledocholithiasis was present, successful treatment occurred through common bile duct exploration. Only one case required conversion from laparoscopic to open surgery. There were no observed severe complications or mortality. Admission CT scans are instrumental in identifying clinically stable patients with local tomographic complications that contraindicate early surgery. Patients meeting the criteria for mild acute gallstone pancreatitis, as per Atlanta guidelines, without SIRS or local complications (Baltazar D/E), can safely undergo early cholecystectomy within the initial 72h of admission.

The application of proximal tibial anterior closing wedge osteotomy in anterior cruciate ligament reconstruction

IntroductionPosterior tibial slope (PTS) plays a vital role in knee stability. PTS of more than 12° may be considered with increased strain on the native anterior cruciate ligament (ACL) fibers. To handle the instability caused by changes in PTS degree, Proximal Tibial Anterior Closing Wedge Osteotomy (PT-ACWO) is adopted by surgeons. MethodsBetween October 2015 and October 2019, our department conducted a retrospective analysis of patients who experienced anterior cruciate ligament reconstruction (ACLR) graft failures, with a particular focus on pathological PTS. The time from initial ACLR to revision ranged from 1 to 10 years, with a mean of 2.5 years. Radiological assessments of PTS were conducted, and outcomes were quantified using the International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale. The surgical technique and the use of 3D Patient-Specific Instrumentation (PSI) were outlined. Preoperative imaging included the use of Kirschner wires to establish tibial plateau reference points, and 3D-PSI was employed to guide the location and depth of the tibial osteotomy, which was performed obliquely. In a notable instance, a novel tibial tunnel was mapped out, and ortho-bridge system (OBS) fixation was utilized to ensure adequate space for the new tunnel. ResultsIn a cohort of seven patients with a mean follow-up of 28.1 months, a significant reduction in PTS was noted postoperatively (median [interquartile range, IQR], from 15.27° [13.46°, 16.60°] to 6.25° [5.89°, 6.78°]; P = 0.002). IKDC score improved to 85.10 (80.25, 88.10), P < 0.001; the Lysholm score to 88.00 (73.00, 90.50), P < 0.001; and the Tegner score to 8.00 (7.20, 8.05), P = 0.025 at final follow-up. Skin incision healing delays occurred in two instances, yet achieved closure by six weeks. Radiographs at three months demonstrated faster bone healing in oblique osteotomies than transverse ones. Knee joint stability was maintained, with no additional complications or evidence of instability noted. Magnetic resonance imaging (MRI) confirmed graft integrity in all patients, without signs of enlargement or mispositioning at last observation. ConclusionAn augmented PTS angle exceeding 12 may constitute a potential etiology for the failure of ACLR grafts. In such patients, the implementation of ACLR combined with PT-ACWO could mitigate the risk of surgical failure during initial ACLR or subsequent revision procedures.

Acute Intraoperative Conversion from Endovascular to Open vs Planned Open Operation for Abdominal Aortic Aneurysm: A Propensity-Score Matched Study from the American College of Surgeons NSQIP-Targeted Database.

Evaluating outcomes for acute intraoperative conversion to open surgery during endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) was difficult due to low incidence. This study aimed to compare 30-day outcomes between patients with acute intraoperative conversion during EVAR and planned open surgery, and to identify risk factors associated with acute conversion. Patients who underwent EVAR or planned open AAA repair were identified in American College of Surgeons NSQIP-targeted databases from 2012 to 2021. Patients with acute intraoperative conversion during EVAR were selected. A 1:3 propensity-score matching was used to match demographics, baseline characteristics, surgical indications, aneurysm size and extent, and emergency cases between the conversion open and planned open groups. Thirty-day postoperative outcomes were assessed. Of 20,566 EVAR cases, 177 (0.86%) had acute intraoperative conversion to open surgery. The conversion open group was matched to 504 of 5,249 planned open patients. Conversion open and planned open groups had comparable 30-day mortality (23.43% vs 17.46%, p = 0.09) and organ system complications, including major adverse cardiovascular event (14.86% vs 10.71%, p = 0.17), pulmonary complications (17.71% vs 24.01%, p = 0.09), and renal complications (8.57% vs 11.11%, p = 0.39). The conversion open group had lower bleeding requiring transfusion (48.57% vs 75.60%, p < 0.01), shorter operation time (p < 0.01), and shorter length of stay (p < 0.01). Other postoperative outcomes did not differ. Risk factors associated with acute intraoperative conversion included ruptured aneurysm with or without hypotension. Protective factors included hypertension and aortic distal aneurysm extent. Although this study does not endorse a universal "EVAR first" strategy for all patients with AAA, EVAR can be attempted first in eligible patients with AAA. Even when EVAR is unsuccessful, intraoperative conversion to open surgery still appears to be safe compared with planned open repair.

A combined endovascular and open repair of innominate artery bifurcation pseudoaneurysm: a case report

BackgroundInnominate artery aneurysms (IAAs) are rare and may result in rupture, distal arterial embolization, or local compression without timely treatment. Rupture is the most dangerous of these complications. This article reports a case of innominate artery bifurcation pseudoaneurysm.Case presentationThe patient was a 45-year-old man who was admitted to the emergency department due to chest discomfort. The computed tomographic angiography (CTA) imaging indicated the presence of a 3.6*2.4 cm saccular aneurysm in the bifurcation of the innominate artery, involving both the right proximal subclavian and common carotid arteries. The patient’s vital signs were normal, there was equal blood pressure in the upper arms and no neurological dysfunction was observed. Gadolinium-enhanced magnetic resonance angiography indicated that the circle of Willis was intact. The treatment involved open surgery combined with endovascular therapy. The external carotid artery was first transposed to the right subclavian artery (RSA) and an 8-mm woven Dacron graft was inserted in the middle. The covered stent graft was then placed in the proximal part of the innominate artery to close the entrance of the aneurysm. Lastly, an occluder was implanted at the origin of the RSA. There were no perioperative or postoperative complications. At 1-year follow-up, no aneurysm was observed on CTA and the right vertebral artery was patent.ConclusionsThis study indicated that the combined use of endovascular therapy and open repair surgery is an effective strategy to treat innominate artery bifurcation pseudoaneurysm.

Oncological survival in pancreatic head ductal carcinoma: hybrid minimally invasive versus open pancreatoduodenectomy - a single centre analysis.

Surgery remains the only curative treatment option for pancreatic head cancer. Laparoscopic surgical techniques are increasingly used, in line with the development of visceral surgery as a whole. The success of surgery is measured by the oncological outcome. Aim of this study is to evaluate the oncological outcome and survival after laparoscopic assisted resection of the pancreatic head compared to open surgery for ductal adenocarcinoma. Data were collected in a prospectively maintained database. Perioperative and oncological outcomes of 182 laparoscopic pancreatic head resections for ductal carcinoma were compared with 585 open pancreatic head resections. The laparoscopic procedures were performed between 2010 and 2022, the open procedures between 2002 and 2022. Laparoscopic procedure was significantly superior in terms of intraoperative blood loss (575 vs. 600mL, P=0.021) and operative time (413 vs. 427 min, P=0.033). Tumour size (25 vs. 27mm, P=0.028), need for portal vein resection (P=0.009) and blood transfusion (P=0.004) were significantly greater in the open group (P=0.009). The resection margin remained negative significantly more often in the laparoscopic group (159 [87%] vs. 449 [77%], P<0.001). There was no difference in postoperative mortality and morbidity. Postoperative survival at 5 years was significantly better in the laparoscopic group (37% vs. 15%, P<0.001). In our cohort, patients who underwent hybrid laparoscopic resection of pancreatic head cancer showed a significantly improved oncological outcome. Most of these effects are due to selection bias, which is not captured by the clinical parameters used to date. Our results highlight the need for additional prognostic factors in pancreatic cancer.

Usefulness of low-cost simulation models to learning surgical techniques for placenta accreta spectrum: An observational educational study.

To evaluate the utility of low-cost simulation models to teach surgical techniques for placenta accreta spectrum (PAS), included in a multimodal education workshop for PAS. This was an observational, survey-based study. Participants were surveyed before and after the use of low-fidelity mannequins to simulate two surgical techniques for PAS (one-step conservative surgery [OSCS] and modified subtotal hysterectomy [MSTH]), within a multimodal educational workshop. The workshops included pre-course preparation, didactics, simulated practice of the techniques using low-cost models, and viewing live surgery. Six OSCS/MSTH training workshops occurred across six countries and a total of 270 participants were surveyed. The responses of 127 certified obstetricians and gynecologists (OB-GYNs) were analyzed. Participants expressed favorable impressions of all components of the simulated session. Perceived anatomical simulator fidelity, scenario realism, educational component effectiveness, and self-assessed performance improvement received ratings of 4-5 (positive end of the Likert scale) from over 90% of respondents. When asked about simulation's role in technique comprehension, comfort level in technique performance, and likelihood of recommending this workshop to others, more than 75% of participants rated these aspects with a score of 4-5 (positively) on the five-point scale. Low-cost simulation, within a multimodal education strategy, is a well-accepted intervention for teaching surgical techniques for PAS.

A new surgical technique to increase airflow in the olfactory cleft: superior turbinate lateralization procedure.

The olfactory cleft (OC) is the most important anatomical site for the maintenance of olfactory function. Obstruction of airflow in the OC by various conditions, such as inflammation, leads to poor olfactory function. Therefore, it is important to increase OC airflow while performing endoscopic sinus surgery (ESS). However, no technique to increase airflow has yet been established. We designed a superior turbinate lateralization (STL) procedure that displaces the entire ST bone laterally by eliminating the connection between the posterior ST and the anterior wall of the sphenoid sinus. The effect of the STL procedure was investigated in terms of anatomy and olfactory function. ESS with the STL procedure was performed on seven patients with chronic rhinosinusitis and nasal polyps. The cross-sectional area of the OC at 3months postoperatively was significantly larger than that before ESS. In addition, the Open Essence test and questionnaires revealed significantly improvements in sense of smell. Airflow in the OC was significantly higher in STL procedure group than in the non-STL procedure group. The STL procedure enlarges the bony framework of the OC, and by increasing OC airflow, facilitates the transport of odorants to the olfactory epithelium, thereby improving olfactory perception.

Safety and cosmesis of gasless endoscopic thyroidectomy: a retrospective study.

Despite growing interest in gasless endoscopic unilateral thyroid lobectomy via the axillary approach, there are a lack of sufficient data on its safety and cosmetic outcomes. This retrospective study analysed the clinical outcomes and postoperative complications of 161 patients who underwent this surgery for thyroid cancer and nodules, with particular attention given to complications and patient satisfaction with cosmetic outcomes. All 161 patients (143 females, 18 males) successfully underwent the operation without conversion to open surgery. Temporary vocal cord paralysis occurred in five patients, with no other serious complications observed. The cosmetic outcomes were generally good, with no recurrences or tumour implantations observed during follow-up. For carefully selected patients, gasless endoscopic unilateral thyroid lobectomy via the axillary approach is not only safe but also provides excellent cosmetic results.

Birth weight and thoracoscopic approach for patients with esophageal atresia and tracheoesophageal fistula-a retrospective cohort study.

This study aimed to analyze the results, feasibility and safety of the thoracoscopic approach for patients with esophageal atresia with tracheoesophageal fistula (EA/TEF) depending on the patient's birth weight. The study involved only type C and D EA/TEF. Among the analyzed parameters were the patients' characteristics, surgical treatment and post-operative complications: early mortality, anastomosis leakage, anastomosis strictures, chylothorax, TEF recurrence, and the need for fundoplication or gastrostomy. 145 consecutive newborns underwent thoracoscopic EA with TEF repair. They were divided into three groups-A (N = 12 with a birth weight < 1500g), B (N = 23 with a birth weight ≥ 1500g but < 2000g), and C-control group (N = 110 with a birth weight ≥ 2000g). Primary one-stage anastomosis was performed in 11/12 (91.7%) patients-group A, 19/23 (82.6%)-group B and 110 (100%)-group C. Early mortality was 3/12 (25%)-group A, 2/23 (8.7%)-group B, and 2/110 (1.8%)-group C and was not directly related to the surgical repair. There were no significant differences in operative time and the following complications: anastomotic leakage, recurrent TEF, esophageal strictures, and chylothorax. There were no conversions to an open surgery. Fundoplication was required in 0%-group A, 4/21 (19.0%)-group B, and 2/108 (1.9%)-group C survivors. Gastrostomy was performed in 1/9 (11.1%)-group A, 3/21 (14.3%)-group B and 0%-group C. In an experienced surgeon's hands, even in the smallest newborns, the thoracoscopic approach may be safe, feasible, and worthy of consideration. Birth weight seems to be not a direct contraindication to the thoracoscopic approach.

Laparoscopic Pancreaticoduodenectomy With Open Reconstruction: The Buddha's Middle Path.

Laparoscopic pancreaticoduodenectomy (LPD) is not universally adopted because of its steep learning curve. Its technical complexity discourages many surgeons. We believe that laparoscopic pancreaticoduodenectomy with open reconstruction (LPOR) has all the benefits of LPD without its drawbacks and combines the ease of open surgery with the benefits of minimal access surgery. We assessed the feasibility and safety of LPOR and compared it with open pancreaticoduodenectomy (OPD), with the objectives being perioperative and short-term clinical/oncologic outcomes. Retrospective review of prospectively maintained database; study period from January 2013 to December 2019. Till 2015, we did only OPD. In 2016, we started with LPD but soon switched to LPOR. The resection part was done laparoscopically and the reconstruction part was done through a 8-cm mini-laparotomy. We did 19 OPDs and 15 LPORs. Demographic data of the 2 groups were comparable. The duration of surgery was significantly longer in the LPOR group (360 vs. 410min; P=0.01), whereas the blood loss and hospital stay were longer in the OPD group (520 vs. 360mL; P=0.03 and 13 vs. 11d; P=0.08, respectively). Clinically significant complication rates, including delayed gastric emptying and postoperative pancreatic fistulas, were not different in either group. No patients in the LPOR group had wound-related/pulmonary complications. Lymph node yield was similar in both groups (20 vs. 22) and we had 100% R0 resections. LPOR was better than OPD in terms of short-term outcomes and was not inferior to OPD in terms of complications/oncologic outcomes.

Continuous cuff pressure control on middle-aged and elderly patients undergoing endoscopic submucosal dissection of the esophagus effect of airway injury.

Assessment of the effect of continuous cuff pressure control on airway injury in middle-aged and elderly patients undergoing endoscopic submucosal dissection (ESD). A total of 104 eligible middle-aged and elderly patients requiring esophageal ESD from July 2022-September 2023 at the First Affiliated Hospital of Nanchang University were selected and randomly divided into two groups: the group undergoing general anesthesia tracheal intubation with continuous control of cuff pressure after intubation (Group A, n = 51) and the group undergoing general anesthesia tracheal intubation with continuous monitoring without control of cuff pressure (Group B, n = 53). After endotracheal intubation in Group A, under the guidance of an automatic cuff pressure controller, the air was used to inflate the tracheal cuff until the cuff pressure was 25-30cmH2O. The cuff pressure after intubation was recorded, and then the cuff pressure parameters were directly adjusted in the range of 25-30cmH2O until tracheal extubation after the operation. After endotracheal intubation, patients in Group B inflated the tracheal cuff with clinical experience, then monitored and recorded the cuff pressure with a handheld cuff manometer and instructed the cuff not to be loosened after being connected to the handheld cuff manometer-continuous monitoring until the tracheal extubation, but without any cuff pressure regulation. The patients of the two groups performed esophageal ESD. The left recumbent position was taken before the operation, and the cuff's pressure was recorded. Then, insert the gastrointestinal endoscope to find the lesion site and perform appropriate CO2 inflation to display the diseased esophageal wall for surgical operation fully. After determining the location, the cuff pressure of the two groups was recorded when the cuff pressure was stable. After the operation, the upper gastrointestinal endoscope was removed and the cuff pressure of the two groups was recorded. Postoperative airway injury assessment was performed in both groups, and the incidence of sore throat, hoarseness, cough, and blood in sputum was recorded. The incidence of postoperative airway mucosal injury was also observed and recorded in both groups: typical, episodic congestion spots and patchy local congestion. The incidence of normal airway mucosa in Group A was higher than that in Group B (P < 0.05). In comparison, the incidence of occasional hyperemia and local plaque congestion in Group A was lower than in Group B (P < 0.05). Continuous cuff pressure control during operation can reduce airway injury in patients with esophageal ESD and accelerate their early recovery after the operation.

Simulation and training for pediatric colorectal surgery and anorectal malformation: a scoping review.

To study the published literature for various models used for simulation and training in the field of pediatric colorectal surgery. A PubMed search was conducted for studies of simulation models in anorectal malformation on 24 March 2024 with the search words 'simulation pediatric colorectal surgery' followed by another search on 'simulation AND anorectal malformation' that gave 22 and 14 results, respectively (total 36). After removing 4 duplicate publications, 12 were found relevant to simulation and training in colorectal diseases. One publication relevant to the topic was added from literature, thirteen articles were studied. Of these, 5; 1; 4; and 3 were on inanimate models; animate model; 3D reconstructions; and training, respectively. Simulation models are available for posterior sagittal anorectoplasty. The same inanimate model was used in five articles. The animate model was based on a chicken cadaver. 3D models have been made for personalized preoperative assessment and to understand the imaging in anorectal malformation. One 3D model was made by regeneration of organoid epithelium. Training modules were made to evaluate surgical dissection, standardize surgical techniques, and improve proficiency. Simulation models are an important tool for teaching the steps of surgery and discussing the nuances of operative complications among mentors and peers. With advances in this field, the development of high-fidelity models, more training modules, and consensus on surgical techniques will benefit surgical training.

Robot-assisted laparoscopic ureteroureterostomy in a child with upper urinary tract duplication

Upper urinary tract duplication remains one of the most challenging pediatric urology conditions. Various operative methods are used in the treatment of children with this pathology; however, reoperation rate remains high. This study aimed to investigate a case of successful robot-assisted laparoscopic ureteroureterostomy and discuss the technical aspects of this procedure and review known series of robotic ureteroureterostomy. The authors retrospectively reviewed the medical history of a child with duplication of the right kidney, accompanied by reflux of urine into the lower segment collecting system. Surgical intervention was performed using robot-assisted technology. Using computed tomography and voiding cystourethrography, duplex kidney with vesicorenal reflux into the lower segment was diagnosed. The surgical technique used was ureteroureterostomy. The donor ureter was divided in the area of the intended anastomosis. Then, a surgical incision was made in the recipient ureter, the length of which was equal to the diameter of the donor ureter. After preparation of the ureters, an end-to-side anastomosis was performed. The operation was successfully performed without intraoperative difficulties or complications and lasted for 140 minutes. The robot installation time (docking time) was 20 minutes, and the main console time was thus 120 minutes. The patient started feeding on the same day after the operation. The drainage tube was removed after a control ultrasound examination on postoperative day 2. The stent remained in the recipient ureter until its removal 6 weeks after surgery. The duration of follow-up was 6 months. The patient was asymptomatic throughout the control period. Repeated ultrasound examination performed after surgery showed a decrease in the anteroposterior diameter of the lower segment pelvis to 5 mm. Blood flow in the upper and lower segments of the right kidney was not impaired. The advantages of the robotic approach, including improved instrument dexterity and 3D visualization, make it a safe and effective alternative to open or laparoscopic surgery in children.

Management of Proximal Hamstring Injuries: Non-operative and Operative Treatment.

To evaluate the current evidence and literature on treatment options for proximal hamstring injuries. Patients with 3-tendon complete tears with greater than 2cm of retraction have worse outcomes and higher complication rates compared to those with less severe injuries. Endoscopic and open proximal hamstring repair both have favorable patient reported outcomes at 5-year follow up. Proximal hamstring repair in patients who are male, with isolated semimembranosus injury, and have proximal hamstring free tendon rupture are more likely to have earlier return to sports. The Parisian Hamstring Avulsion Score (PHAS) is a validated patient-reported outcome measure to predict return to sports. Proximal hamstring injuries may occur in both elite and recreational athletes and may present with varying degrees of chronicity and severity. Injuries occur most commonly during forceful eccentric contraction of the hamstrings and often present with ischial tuberosity tenderness, ecchymosis, and hamstring weakness. Treatment decision-making is dictated by the tendons involved and chronicity. Many proximal hamstring injuries can be successfully treated with non-surgical measures. However, operative treatment of appropriately indicated proximal hamstring tendon injuries can result in significantly better functional outcomes and faster and more reliable return to sports compared to nonoperative treatment. Both endoscopic and open surgical repair techniques show high satisfaction levels and excellent patient-reported outcomes at short- and mid-term follow-up. Postoperative rehabilitation protocols vary across the literature and ongoing study is needed to clarify the optimal program, though emphasis on eccentric hamstring strengthening may be beneficial.

Simple model of pulmonary hypertension secondary to left heart pressure overload induced by partial intravascular occlusion of the ascending aorta.

Pulmonary hypertension is a group of diseases characterized by elevated pulmonary artery pressure and pulmonary vascular resistance with significant morbidity and mortality. The most prevalent type is pulmonary hypertension secondary to left heart disease (PH-LHD). The available experimental models of PH-LHD use partial pulmonary clamping by technically nontrivial open chest surgery with lengthy recovery. We present a simple model in which reduction of the cross-sectional area of the ascending aorta is achieved not by external clamping, but by partial intravascular obstruction without opening the chest. In anesthetized rats, a blind polyethylene tubing was advanced from the right carotid artery to just above the aortic valve. The procedure is quick and easy to learn. Three weeks after the procedure, left heart pressure overload was confirmed by measuring left ventricular end diastolic pressure by puncture (1.3±0.2 vs. 0.4±0.3 mmHg in controls, mean±sd, P<0.0001). The presence of pulmonary hypertension was documented by measuring pulmonary artery pressure by catheterization (22.3±2.3 vs. 16.9±2.7 mmHg, P=0.0282) and by detecting right ventricular hypertrophy and increased muscularization of peripheral pulmonary vessels. Contributions of precapillary vascular segment and of vasoconstriction to the increased pulmonary vascular resistance were demonstrated, respectively, by arterial occlusion technique and by normalization of resistance by a vasodilator, sodium nitroprusside, in isolated lungs. These changes were comparable, but not additive, to those induced by an established pulmonary hypertension model, chronic hypoxic exposure. Intravascular partial aortic obstruction offers an easy model of pulmonary hypertension induced by left heart disease that has a vasoconstrictor and precapillary component.

A new technique to implant intracorneal ring-segments from the perilimbal region: one-year prospective pilot study report

BackgroundRecently a new surgical technique for intracorneal ring-segments (ICRS) assisted by femtosecond laser (FSL) called ByLimB was developed, involving the creation of the incision from a paralimbic region. This study aims to evaluate the safety and efficacy of the ByLimb technique following one year of follow-up.MethodsA prospective, single-center study was conducted at the Zaldivar Institute in Buenos Aires, Argentina. Keratoconus patients with indication for ICRS-FSL assisted procedure, operated with the ByLimb technique were included. By using the ByLimb technique, the ICRS are placed without affecting the tunnel’s roof, and the end of the ICRS is always away from the incision area. Visual acuity, topographic astigmatism, and the occurrence of complications were evaluated. Safety index was the main outcome and efficacy indes was a complimentary outcome.ResultsA total of 17 eyes completed the 12-month follow-up period. The safety index was 1.10 (mean postoperative corrected distance visual acuity (CDVA) in decimal: 0.76/preoperative CDVA: 0.69), while the efficacy index was 0.89 (mean postoperative uncorrected distance visual acuity UDVA in decimal: 0.62/preoperative CDVA: 0.69). Mean preoperative astigmatism was 5.3 ± 2.3, decreasing twelve months after surgery at 2.1 ± 1.2 (p < 0.001). No eye loss lines of vision and no intraoperative complications were observed. During the first month after surgery, an improper positioning of the ICRS based on topographic assessment was detected in five cases. A second procedure was performed, which consisted of opening the incision and introducing a Sinsky hook, through which the ICRS was mobilized and placed in its correct position. No incisional alterations, signs of infection, anterior segment anomalies, or fundus alterations were observed.ConclusionFSL-assisted ICRS implantation through the perilimbal region has demonstrated an adequate safety index one year post-surgery. Additionally, this technique has facilitated accurate realignment of ICRS during secondary surgical interventions within one-month post-surgery. While the current findings are promising, continued follow-up of these cases is warranted.

Regeneration of Osteochondral Lesion of the Talus with Retrograde Drilling Technique: An In Vitro Pilot Study

Background: Retrograde Drilling (RD) is a surgical technique employed for osteochondral lesions of the talus (OCLTs) to reach the subchondral bone lesion from behind, thus preserving cartilage integrity. The aim of the present pilot study was to set up an in vitro model of OCLTs to evaluate the regenerative potential of biological approaches that could be associated with the RD technique. Methods: For this purpose, an OCLT was created in human osteochondral specimens, to try to mimic the RD technique, and to compare the regenerative potential of two biological treatments. For this purpose, three groups of treatments were performed in vitro: (1) no treatment (empty defect); (2) autologous bone graft (ABG); (3) hyaluronic membrane enriched with autologous bone marrow cells. Tissue viability; production of Collagen I and II, Vascular Endothelial Growth Factor, and Aggrecan; and histological and microCT evaluations were performed after 30 days of culture in normal culture conditions. Results: It was observed that Group 3 showed the highest viability, and Group 2 showed the highest protein production. From a histological and microtomographic point of view, it was possible to appreciate the structure of the morcellized bone with which the defect of Group 2 was filled, while it was not yet possible to observe the deposition of mineralized tissue in Group 3. Conclusions: To conclude, this pilot study shows the feasibility of an alternative in vitro model to evaluate and compare the regenerative potential of two biological scaffolds, trying to mimic the RD technique as much as possible. The tissues remained vital for up to 4 weeks and both ABG and hyaluronic acid-based scaffolds stimulated the release of proteins linked to regenerative processes in comparison to the empty defect group.