Reinforced tissue matrix to strengthen the abdominal wall following reversal of temporary ostomies or to treat incisional hernias

BACKGROUND Abdominal wall deficiencies or weakness are a common complication of tem-porary ostomies,and incisional hernias frequently develop after colostomy or ileostomy takedown.The use of synthetic meshes to reinforce the abdominal wall has reduced hernia occurrence.Biologic meshes have also been used to enhance healing,particularly in contaminated conditions.Reinforced tissue matrices(R-TMs),which include a biologic scaffold of native extracellular matrix and a syn-thetic component for added strength/durability,are designed to take advantage of aspects of both synthetic and biologic materials.To date,RTMs have not been reported to reinforce the abdominal wall following stoma reversal.METHODS Twenty-eight patients were selected with a parastomal and/or incisional hernia who had received a temporary ileostomy or colostomy for fecal diversion after rectal cancer treatment or trauma.Following hernia repair and proximal stoma closure,RTM(OviTex®1S permanent or OviTex®LPR)was placed to reinforce the abdominal wall using a laparoscopic,robotic,or open surgical approach.Post-operative follow-up was performed at 1 month and 1 year.Hernia recurrence was determined by physical examination and,when necessary,via computed tomo-graphy scan.Secondary endpoints included length of hospital stay,time to return to work,and hospital readmissions.Evaluated complications of the wound/repair site included presence of surgical site infection,seroma,hematoma,wound dehiscence,or fistula formation.RESULTS The observational study cohort included 16 male and 12 female patients with average age of 58.5 years±16.3 years and average body mass index of 26.2 kg/m^(2)±4.1 kg/m^(2).Patients presented with a parastomal hernia(75.0%),in-cisional hernia(14.3%),or combined parastomal/incisional hernia(10.7%).Using a laparoscopic(53.6%),robotic(35.7%),or open(10.7%)technique,RTMs(OviTex®LPR:82.1%,OviTex®1S:17.9%)were placed using sublay(82.1%)or intraperitoneal onlay(IPOM;17.9%)mesh positioning.At 1-month and 1-year follow-ups,there were no hernia recurrences(0%).Average hospital stays were 2.1 d±1.2 d and return to work occurred at 8.3 post-operative days±3.0 post-operative days.Three patients(10.7%)were readmitted before the 1-month follow up due to mesh infection and/or gastrointestinal issues.Fistula and mesh infection were observed in two patients each(7.1%),leading to partial mesh removal in one patient(3.6%).There were no complications between 1 month and 1 year(0%).CONCLUSION RTMs were used successfully to treat parastomal and incisional hernias at ileostomy reversal,with no hernia recurrences and favorable outcomes after 1-month and 1-year.

Occurrence and prevention of incisional hernia following laparoscopic colorectal surgery

Among minimally invasive surgical procedures,colorectal surgery is associated with a notably higher incidence of incisional hernia(IH),ranging from 1.7% to 24.3%.This complication poses a significant burden on the healthcare system annually,necessitating urgent attention from surgeons.In a study published in the World Journal of Gastrointestinal Surgery,Fan et al compared the incidence of IH among 1614 patients who underwent laparoscopic colorectal surgery with different extraction site locations and evaluated the risk factors associated with its occurrence.This editorial analyzes the current risk factors for IH after laparoscopic colorectal surgery,emphasizing the impact of obesity,surgical site infection,and the choice of incision location on its development.Furthermore,we summarize the currently available preventive measures for IH.Given the low surgical repair rate and high recurrence rate associated with IH,prevention deserves greater research and attention compared to treatment.

Clinical observation of extraction-site incisional hernia after laparoscopic colorectal surgery

BACKGROUND Laparoscopic colorectal cancer surgery increases the risk of incisional hernia(IH)at the tumor extraction site.AIM To investigate the incidence of IH at extraction sites following laparoscopic colo-rectal cancer surgery and identify the risk factors for IH incidence.METHODS This study retrospectively analyzed the data of 1614 patients who underwent la-paroscopic radical colorectal cancer surgery with tumor extraction through the abdominal wall at our center between January 2017 and December 2022.Diffe-rences in the incidence of postoperative IH at different extraction sites and the risk factors for IH incidence were investigated.RESULTS Among the 1614 patients who underwent laparoscopic radical colorectal cancer surgery,303(18.8%),923(57.2%),171(10.6%),and 217(13.4%)tumors were ex-tracted through supraumbilical midline,infraumbilical midline,umbilical,and off-midline incisions.Of these,52 patients developed IH in the abdominal wall,with an incidence of 3.2%.The incidence of postoperative IH was significantly higher in the off-midline incision group(8.8%)than in the middle incision groups[the supraumbilical midline(2.6%),infraumbilical midline(2.2%),and umbilical incision(2.9%)groups](χ^(2)=24.985;P<0.05).Univariate analysis showed that IH occurrence was associated with age,obesity,sex,chronic cough,incision infection,and combined diabetes,anemia,and hypopro-teinemia(P<0.05).Similarly,multivariate analysis showed that off-midline incision,age,sex(female),obesity,incision infection,combined chronic cough,and hypoproteinemia were independent risk factors for IH at the site of laparoscopic colorectal cancer surgery(P<0.05).CONCLUSION The incidence of postoperative IH differs between extraction sites for laparoscopic colorectal cancer surgery.The infraumbilical midline incision is associated with a lower hernia rate and is thus a suitable tumor extraction site.

Hybrid IPOM: A Novel Technique for the Management of Incisional Hernia

Background and Aim: The incidence of incisional hernias has been reported to be around 15%. In the present scenario, a wide array of surgical procedures are available for their better management. In this study, we intend to share our experience with one novel technique, “Hybrid IPOM (Intraperitoneal onlay meshplasty)” as a management option for a selected cohort of patients. Methods: This prospective study was undertaken during January 2019 to July 2023 at King Abdullah medical city, Makkah. A total of 51 cases were selected for Hybrid IPOM repair as per inclusion criteria;medium sized (4 - 10 cm) hernia defects;uncomplicated hernias;age more than 18 years. The follow-up period of the patients varied from 6 months to 4 years. The operation commenced with open hernia dissection, mesh deployment into abdomen, defect closure and then conversion to laparoscopy for the posterior mesh placement. Results: A total of 51 cases were repaired successfully with this technique. 48 out of 51 cases were incisional hernias secondary to some primary procedure done either for hernias itself or some other intra-abdominal pathology. The three cases were primary hernias falling in medium to large category with unaesthetic overlying skin. The age range was 19 to 72 years. The mean (range) operative time was 135 (90 - 240) min, and the average blood loss was 70 ml. The mean (range) hospital stay was 3 (2 - 11) days. All patients returned to routine work within 2 - 3 weeks of surgery. The median follow-up was 15 (6 - 48) months. Of the 51 cases, 3 patients developed seroma (managed conservatively), 1 patient developed a large hematoma (needed evacuation), and 1 patient developed superficial wound infection (managed with antibiotics). Two patients had recurrences;one patient had previously failed multiple repairs, and the other developed a postoperative hematoma. None of our patients had an iatrogenic bowel injury. Conclusion: Hybrid IPOM technique is a safe, feasible and easily reproducible technique. It may prove easier especially for beginners in laparoscopy, as it achieves faster and easy adhesiolysis thereby reducing operative time and easier establishment of the pneumoperitoneum. Besides, it gives the chance to excise ugly scars and improve the cosmesis.

Laparoscopic Surgery of Incisional Hernia: Technique and Short-Term Results in Three Surgical Units in Cameroon

Introduction: Incisional hernia is a common medical situation and its treatment has always been a challenge for general surgeons. If laparoscopic repair has become a gold standard elsewhere, it is increasingly done in our milieu, but no data has been found. The aim of this study was to review this surgery done in our country so far, to describe the operative technique and to evaluate the postoperative outcomes. Patients and Methods: We conducted an observational descriptive study with retrospective collection of data from the 1st of July 2018 to 30th of June 2022, in three hospitals in Cameroon. Data on socio-demographic and clinical characteristics, surgical technique and postoperative outcomes of patients who had a laparoscopic repair of their incisional hernia were collected. Results: We reviewed 20 files. There were 14 women with an average age of 54.6 years. The average BMI was 32.8 kg/m2. Thirteen patients had a moderate size hernia and the hernia was localized at the midline in 18 cases. Only composite biface meshes were used with dimensions chosen to obtain at least 5 cm overlap. Spiral tacks were the only fixation means used. We registered 3 complications. One case of generalized peritonitis secondary to missed digestive perforation, one case of seroma and one case of postoperative ileus. We registered no death. Conclusion: Laparoscopic repair of incisional hernias is feasible in a resource-limited setting like ours. Compliance with the operative technique and recommendations is important to obtain short-term results closed to that put forward by literature.

Endoscopic incisional therapy for benign esophageal strictures: Technique and results

Benign esophageal strictures refractory to the conventional balloon or bougie dilatation may be subjected to various adjunctive modes of therapy, one of them being endoscopic incisional therapy(EIT). A proper delineation of the stricture anatomy is a prerequisite. A host of electrocautery and mechanical devices may be used, the most common being the use of needle knife, either standard or insulated tip. The technique entails radial incision and cutting off of the stenotic rim. Adjunctive therapies, to prevent re-stenosis, such as balloon dilatation, oral or intralesional steroids or argon plasma coagulation can be used. The common strictures where EIT has been successfully used are Schatzki's rings(SR) and anastomotic strictures(AS). Short segment strictures(< 1 cm) have been found to have the best outcome. When compared with routine balloon dilatation, EIT has equivalent results in treatment na?ve cases but better long term outcome in refractory cases. Anecdotal reports of its use in other types of strictures have been noted. Post procedure complications of EIT are mild and comparable to dilatation therapy. As of the current evidence, incisional therapy can be used for management of refractory AS and SR with relatively short stenosis(< 1 cm) with good safety profile and acceptable long term patency.

Modified rives-stoppa repair for abdominal incisional hernias

Incisional hernias are a prevalent problem in abdominal surgery and occur in 11% of patients who undergo laparotomy. Primary suture clo-sure of incisional hernias results in a 31%-58% chance of recurrence. The addition of a pros-thetic mesh implant decreases recurrence rates to 8%-10%. Popularized in Europe by Rives and Stoppa, the sublay technique has proven to be very effective, with low recurrence rates (0%-23%) and minimal complications. The pur-pose of the study was to evaluate the experi-ence of a single surgeon at a large tertiary care center performing a modified Rives-Stoppa re-pair for abdominal incisional hernias. To do this, the records of all patients undergoing a modi-fied Rives-Stoppa incisional hernia repair be-tween January 2000 and August 2003 were ret-rospectively reviewed. Outpatient clinic notes, discharge summaries, operative reports, and laboratory data were reviewed for patient demographics, surgical data and postoperative complications. Univariate analysis was per-formed in order to identify predictors for recur-rence. During the study period, 83 patients un-derwent a modified Rives-Stoppa incisional hernia repair. Nineteen patients were excluded due to incomplete medical records. No patients required postoperative exploration for an in-tra-abdominal catastrophe. Twenty-five percent (n=16) of patients had a complication as a result of the hernia repair. Only two patients (3.1%) developed recurrent incisional hernias. History of diabetes (p=0.007) and benign prostatic hy-perplasia (p=0.000) were the only significant predictors for recurrence. The results presented here confirm that the modified Rives-Stoppa retromuscular repair is an effective method for the repair of incisional hernias. The complica-tion and recurrence rates compare favorably to results for currently popular alternative tech-niques.

Segmental liver incarceration through a recurrent incisional lumbar hernia

BACKGROUND:Lumbar hernia is a rare congenital or acquired defect of the posterior abdominal wall. The acquired type is more common and occurs mainly as an incisional defect after flank surgery. Incarceration or strangulation of hernia contents is uncommon. METHOD:Segmental liver incarceration through a recurrent incisional lumbar defect was diagnosed in a 58 years old woman by magnetic resonance imaging. RESULTS:The patient underwent an open repair of the com-plicated hernia. An expanded polytetraflouoroethylene(e-PTFE) mesh was fashioned as a sublay prosthesis. She had an uncomplicated postoperative course. Follow-up examinations revealed no evidence of recurrence. CONCLUSIONS:Although lumbar hernia rarely results in incarceration or strangulation,early repair is necessary because of the risks of complications and the increasing difficulty in repairment as it enlarges. Surgical repair is often difficult and challenging.

Incisional Hernias: Risk Factors and Treatment in a Context of Limited Resources

Background: The purpose of this study was to describe the etiologic factors and therapeutic modalities of incisional hernias in the department of surgery at the regional hospital of Tenkodogo, in Burkina Faso. Methods: It is a cross sectional study covering the period from 2010 to 2012. Sampling was comprehensive, including all the patients operated for incisional hernias during this period. Results: Fifty-four patients were included. Their average age was 22.3 years. There were 35 (64.8%) males and 19 (35.2%) female patients. We counted 28 large-size incisional hernias, 14 medium-size incisional hernias and 12 incisional hernias of small size. The average time from the first surgery to the diagnosis of incisional hernias was 8 months. Generalized acute peritonitis (44.4%) and acute intestinal obstructions (22.2%) were the main indications of initial surgical interventions. Vertical midline incisions have been involved in 37 cases (68.5%). Therapeutically, two surgical techniques have been used: open suture repair and open mesh repair. Forty-two patients (77.8%) were treated by open suture repair. Twelve patients (22.2%) benefited from open mesh repair. Post-operative complications were noted in 2 patients. Nine patients (16.7%) presented a recurrence after 12 months. Conclusion: In the rural area of Burkina Faso, incisional hernias occur in young patients. Emergencies with abdominal Infections are the main operative indications. Prostheses are relatively high cost and less accessible. The recidivism rate is high.

Role of botulinum toxin a in the management of complex incisional hernias

Despite the technological breakthroughs and discover of abdominal meshes, ventral hernia has always been challenging in therapeutic strategies by the surgeons, with high recurrence rates. The use of botulinum toxin A (BTA) for the management of ventral and incisional hernia (IH) poses an increasingly interesting practice, especially for the intimidating complex one. The preoperative administration of the toxin to the lateral abdominal muscles by use of Ultra-Sound guidance causes muscle paralysis and a reduction of intraabdominal pressure. Thus, the hernia defect can be primarily closed without tension, if the length of the defect is up to 10 cm. In larger hernia, this method can be combined with component separation techniques or the use of a mesh. The mesh placement seems to be better by laparoscopy. The site of injection and the dosage of BTA are still under discussion amongst authors. The optimal administration is proposed by some authors to be at least 2 weeks before repair. There is also an analgesic effect of BTA to the patients that underwent hernia reconstruction. Ultimately, the role of BTA in the reconstruction of ventral hernia seems to be promising, but there is a necessity for several randomized clinical trials.

Acute Appendicitis Confined to an Incisional Hernia Following Renal Transplantation

We present a case of a 57 years old moderately obese woman with a known 12 cmincisional hernia, who subsequently developed an incarcerated acute appendicitis. The patient underwent an uneventful orthotopic liver and renal transplant five years prior, and was compliant with ongoing immunosuppression without rejection. She presented with 8 hours of acute onset right lower quadrant pain, associated with anorexia, documented fevers, and nausea. Noncontrast CT demonstrated a blind-ending tubular structure with an enhancing and thickened wall within a hernia defect of the right lower quadrant. The patient underwent emergent laparotomy and a non-perforated appendix was completely excised at its base. Discussion: There have been documented reports of an acute appendicitis associated with inguinal hernias, given the eponym Amyand’s hernia. Appendicitis may present within hernias, and there should be a low threshold for radiologic assessment of its components when there is clinical doubt about the symptoms associated with the hernia. Our recommendation prompts early use of non-contrast CT scan in transplant patients with known hernias on examination and abdominal tenderness over the renal allograft considering the high risk of perforation of acute appendicitis and strangulation.

A Rare Interstitial Type of Post Appendectomy Incisional Hernia

Intraparietal Hernias are hernias occurring in the anterior abdominal wall at different anatomical planes. An interparietal hernia has a hernial sac that passes between the layers of the anterior abdominal wall. Appendectomy is a very common surgical procedure, and post appendectomy incisional hernia is a very rare complication. Here we present a case of a 24-year-old male with swelling in the right hypochondrium and lumbar region with an open appendectomy scar. He was diagnosed to have an interparietal hernia in the anterior abdominal wall. After obtaining consent patient was taken up for surgery. At surgery, the patient was found to have a defect in the transverse abdominis muscle with a medial leaf far from the incision site. Open repair of the defect along with double breasting of external oblique done. Interparietal hernias are rare in post appendectomy scar and this case is of significance since it Highlights a rare interstitial type incisional hernia, as a complication of post appendectomy scar, and not many cases reports are mentioned in literature.

Incisional Negative Pressure Wound Therapy in the Prevention of Surgical Site Infection after Vascular Surgery with Inguinal Incisions: Rationale and Design of a Randomized Controlled Trial (INVIPS-Trial)

Background/Aims: Inguinal incisions are a common route of access in vascular surgery. Due to anatomical challenges and a diverse bacterial flora in this area, surgical site infections (SSI) represent a common, debilitating and sometimes life-threatening complication. The INVIPS-Trial evaluates the role of Negative Pressure Wound Therapy (NPWT) on closed inguinal incisions in elective vascular surgery to prevent SSI and other wound complications. Methods: This randomized controlled trial (RCT) registered at ClinicalTrials.gov (Identifier: NCT01913132) compares the effects of a NPWT dressing (PICO, Smith & Nephew, UK) and the center’s standard wound dressing (Vitri Pad, ViTri Medical, Sweden) on postoperative wound complications, especially SSI. The study includes two distinct vascular procedures with different SSI risk profiles: endovascular aortic repair (EVAR) and open surgical approaches involving the common femoral artery (OPEN). Results: Four hundred ninety-five groin incisions in both treatment arms are anticipated to be included in the EVAR group and 147 inguinal incisions in both treatment arms in the OPEN group. Since a large percentage of inguinal vascular procedures in both groups but especially in the EVAR group are performed bilaterally, many patients can serve as their own control by randomly receiving NPWT on one and the standard dressing on the contralateral inguinal incision. Conclusions: This ongoing RCT attempts to elucidate the potential benefit of NPWT on closed inguinal incisions after different vascular procedures. Outcome and conclusions of this trial could have implications on postoperative wound care of patients in both vascular surgery and other surgical specialties.

Robotic versus open transversus abdominis release and incisional hernia repair: A case-control study

Objective:Transversus abdominus release(TAR)is often required to achieve apposition of the rectus muscles and achieve wide mesh reinforcement of the abdominal wall.Traditionally,TAR has been done with an open technique(oTAR),and the benefits of the newer robotic approach(rTAR)has not been well established in the Australian setting.The aim of this study was to compare the results of oTAR with rTAR to demonstrate its safety and efficacy.Methods:A retrospective review of patients who underwent rTAR and oTAR at two tertiary hospitals was conducted between January 2018 and January 2020 in New South Wales,Australia.Patient demographics,perioperative and postoperative outcomes were compared in both groups.Results:There were 26 patients identified to have undergone TAR(13 rTAR,13 oTAR).Both groups were comparable in regards to age,sex and defect size.oTAR was associated with a higher American Society of Anaesthesiologist score.rTAR was associated with significantly longer average operative time(260.0±78.9 min vs.185.7±64.5 min,p=0.017)but found to have a significantly shorter length of stay(3.6±2.1 d vs.6.9±3.6 d,p=0.007)with a comparable complication rate.Conclusions:rTAR is associated with shorter length of hospital stay with comparable postoperative outcomes when compared to oTAR.We are seeing increasing evidence supporting the safety and benefits of robotics,however larger scale studies are required to fully understand this approach.

The Usefulness of Magnetic Resonance Imaging in the Preoperative Study and Postoperative Control in the Laparoscopic Treatment of the Incisional Hernia

Background and Objectives: The aim of this study is to evaluate the usefulness of Magnetic Resonance Imaging (MRI) for planning surgery and postoperative control of complex cases of abdominal wall hernia. Methods: Included in a prospective data base with more than 350 patients treated in two centers, a prospective study over ten patients with complex incisional hernias was designed. In all cases, preoperative diagnosis study and postoperative imaging control by MR Imaging were established. In the early and late follow-up controls, local and general complications were specifically noted and studied by MRI in each case. Results: The preoperative MRI was effective method for an adequate understanding of the defects and hernia sack content. In the postoperative control, the MRI was useful in the follow-up of the mesh integration, detection of complications and diagnosis of the relapsing. Conclusion: In our experience the MRI test is specially recommended in the preoperative workup of complex cases of incisional hernia.

Analgesic effect of intrathecal bumetanide is accompanied by changes in spinal sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 expression in a rat model of incisional pain

Accumulating evidence has demonstrated that the sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 have a role in the modulation of pain transmission at the spinal level through chloride regulation in the pain pathway and by effecting neuronal excitability and pain sensitization. The present study aimed to investigate the analgesic effect of the speciifc sodium-potassium-chloride co-transporter 1 inhibitor bumetanide, and the change in spinal sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 expression in a rat model of incisional pain. Results showed that intrathecal bumetanide could decrease cumulative pain scores, and could increase thermal and mechanical pain thresholds in a rat model of incisional pain. Sodium-potassium-chloride co-transporter 1 expression in-creased in neurons from dorsal root ganglion and the deep laminae of the ipsilateral dorsal horn following incision. By contrast, potassium-chloride co-transporter 2 expression decreased in neurons of the deep laminae from the ipsilateral dorsal horn. These ifndings suggest that spinal sodium-potassium-chloride co-transporter 1 expression was up-regulated and spinal potassi-um-chloride co-transporter 2 expression was down-regulated following incision. Intrathecal bumetanide has analgesic effects on incisional pain through inhibition of sodium-potassi-um-chloride co-transporter 1.

Micro-power negative pressure wound technique reduces risk of incision infection following loop ileostomy closure

BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complication after ileostomy closure.AIM To evaluate the efficacy and safety of the micro-power negative pressure wound technique(MPNPWT)in preventing incisional SSI.METHODS This was a prospective,randomized controlled clinical trial conducted at a single center.A total of 101 consecutive patients who underwent ileostomy closure after rectal cancer surgery with a prophylactic ileostomy were enrolled from January 2019 to December 2021.Patients were randomly allocated into an MPNPWT group and a control group.The MPNPWT group underwent intermittent suturing of the surgical incision with 2-0 Prolene and was covered with a micro-power negative pressure dressing.The surgical outcomes were compared between the MPNPWT(n=50)and control(n=51)groups.Risk factors for incisional SSI were identified using logistic regression.RESULTS There were no differences in baseline characteristics between the MPNPWT(n=50)and control groups(n=51).The incisional SSI rate was significantly higher in the control group than in the MPNPWT group(15.7%vs 2.0%,P=0.031).However,MPNPWT did not affect other surgical outcomes,including intra-abdominal complications,operative time,and blood loss.Postoperative hospital stay length and hospitalization costs did not differ significantly between the two groups(P=0.069 and 0.843,respectively).None of the patients experienced adverse effects of MPNPWT,including skin allergy,dermatitis,and pain.MPNPWT also helped heal the infected incision.Our study indicated that MPNPWT was an independent protective factor[odds ratio(OR)=0.005,P=0.025)]and diabetes was a risk factor(OR=26.575,P=0.029)for incisional SSI.CONCLUSION MPNPWT is an effective and safe way to prevent incisional SSI after loop ileostomy closure.

Applications of SMILE-extracted lenticules in ophthalmology

AIM:To review recent innovations,challenges,and applications of small incision lenticule extraction(SMILE)extracted lenticule for treating ocular disorders.METHODS:A literature review was performed in the PubMed database,which was last updated on 30 December 2021.There was no limit regarding language.The authors evaluated the reference lists of the collected papers to find any relevant research.RESULTS:Due to the simplicity and accuracy of modern femtosecond lasers and the extensive development of SMILE surgery,many healthy human corneal stromal lenticules were extracted during surgery,motivating some professionals to investigate the SMILE lenticule reusability in different ocular disorders.In addition,new approaches had been developed to preserve,modify,and bioengineer the corneal stroma,leading to the optimal use of discarded byproducts such as lenticules from SMILE surgery.The lenticules can be effectively re-implanted into the autologous or allogenic corneas of human subjects to treat refractive errors,corneal ectasia,and corneal perforation and serve as a patch graft for glaucoma drainage devices with better cosmetic outcomes.CONCLUSION:SMILE-extracted lenticules could be a viable alternative to human donor corneal tissue.

Changes in posterior corneal elevation after small incision lenticule extraction for different myopic diopters

●AIM:To study the changes and effect factors of posterior corneal surface after small incision lenticule extraction(SMILE)with different myopic diopters.●METHODS:Ninety eyes of 90 patients who underwent SMILE were included in this retrospective study.Patients were allocated into three groups based on the preoperative spherical equivalent(SE):low myopia(SE≥-3.00 D),moderate myopia(-3.00 D>SE>-6.00 D)and high myopia(SE≤-6.00 D).Posterior corneal surfaces were measured by a Scheimpflug camera preoperatively and different postoperative times(1wk,1,3,6mo,and 1y).Posterior mean elevation(PME)at 25 predetermined points of 3 concentric circles(2-,4-,and 6-mm diameter)above the best fit sphere was analyzed.●RESULTS:All surgeries were completed uneventfully and no ectasia was found through the observation.The difference of myopia group was significant at the 2-mm ring at 1 and 3mo postoperatively(1mo:P=0.017;3mo:P=0.018).The effect of time onΔPME was statistically significant(2-mm ring:P=0.001;4-mm ring:P<0.001;6-mm ring:P<0.001).The effect of different corneal locations onΔPME was significant except 1wk postoperatively(1mo:P=0.000;3mo:P=0.000;6mo:P=0.001;1y:P=0.001).Posterior corneal stability was linearly correlated with SE,central corneal thickness,ablation depth,residual bed thickness,percent ablation depth and percent stromal bed thickness.●CONCLUSION:The posterior corneal surface changes dynamically after SMILE.No protrusion is observed on the posterior corneal surface in patients with different degrees of myopia within one year after surgery.SMILE has good stability,accuracy,safety and predictability.

Ten-year observation of corneal densitometry and associated factors following small incision lenticule extraction

●AIM:To investigate the long-term changes of corneal densitometry(CD)and its contributing elements after small incision lenticule extraction(SMILE).●METHODS:Totally 31 eyes of 31 patients with mean spherical equivalent of-6.46±1.50 D and mean age 28.23±7.38y were enrolled.Full-scale examinations were conducted on all patients preoperatively and during followup.Visual acuity,manifest refraction,axial length,corneal thickness,corneal higher-order aberrations,and CD were evaluated.●RESULTS:All surgeries were completed successfully without complications or adverse events.Ten-year safety index was 1.17±0.20 and efficacy 1.04±0.28.CD value of 0–6 mm zones in central layer was statistically significantly lower 10y postoperatively,compared with preoperative values(0–2 mmΔ=-1.62,2–6 mmΔ=-1.24,P<0.01).There were no correlations between CD values and factors evaluated.●CONCLUSION:SMILE is a safe and efficient procedure for myopia on a long-term basis.CD values get lower 10y postoperatively,whose mechanism is to be further discussed.