Location Of Perforation Research Articles

EGS SO27 - Removable covered stent as an alternative to traditional methods in management of Oesophageal Perforation in unfit surgical patients: A Tertiary Care Hospital Experience

Abstract Background Oesophageal perforation in elderly and frail patients carries a significantly higher mortality rate. Traditionally, management involves surgery for patients who are fit for surgery, or a conservative approach for those with minimal contamination. Endoscopy, with procedures such as endoscopic washout of mediastinal collections and placement of covered removable stents, sometimes in conjunction with chest drain insertion, is emerging as a minimally invasive option for a selected group of patients who are not suitable for traditional methods. This technique aims to seal perforations, promote healing, and facilitate early restoration of oral intake. Method This retrospective study was conducted at a tertiary care hospital. Data were collected over a 10-year period starting from 2012. The study enrolled all patients aged 18 and older, admitted with oesophageal perforation and underwent oesophageal stent insertion. SX-ELLA Danis-seal stents (30-25-30 × 135mm) were used for benign perforations, while permanent covered metal stents were used for patients with underlying malignancy. Variables analyzed included age, gender, Charlson Comorbidity Index (CCI), WHO performance status, location and size of esophageal perforation, type and dimensions of stent used, length of hospital stay, and mortality rates. Data analysis was conducted using SPSS version 25. Results During study period, 11 out of 78 patients with esophageal perforation underwent stent insertion (M:F=7:4, median age-71 (range 48-85) years, median CCI -5). Causes included spontaneous perforation (n=3,27.3%), iatrogenic (n=4,36.4%), and malignancy (n=4,36.4%). Distal esophageal perforation was observed in 7 patients (63.6%). Oral intake was commenced within 72 hours post-insertion. A single procedure sufficed for 10(90%) patients. Stents used for non-malignant perforations were removed endoscopically after an average of 12 weeks. No major complications; minor complications included stent migration (n=1, 9.1%), failed placement (n=1, 9.1%), and loss to follow-up (n=1, 9.1%). The 90-day mortality rate was 45.5% (n=5/11). Conclusion Endoscopy with mediastinal cavity washout and insertion of a covered metal stent in unfit surgical patients provides an alternative and improves outcomes. It could also be considered in patients with non-healing perforations to facilitate early resumption of oral intake.

Correlation of Air-Bone Gap on Pure Tone Audiometry with the Size of Perforation Assessed on Oto-Endoscopy.

To determine the correlation between the air-bone gap on pure tone audiometry with size of perforation oto-endoscopically. Study Design: A descriptive study. Place and Duration of the Study: Department of ENT - Head and Neck Surgery, Dow University of Health Sciences (DUHS), from February 2020 to August 2021. Methodology: A total of 43 patients with dry central pars tensa tympanic membrane perforation were diagnosed through oto-endoscopy during the study. The mean air-bone gap was calculated by assessing each air-bone gap through pure tone audiometry at different frequencies i.e., 250 Hz, 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz. Air-bone gap was found to be the average value of these frequencies. The photograph of the tympanic membrane was taken oto-endoscopically, and the ratio between size of the perforation to the entire area of the tympanic membrane was measured. During the course of the study, a total of 43 patients agreed to provide consent for this study. Out of the 43 patients, 16 (37.2%) were males and 27 (62.8%) were females. The age range was from 18 to 50 years with average age of 38.302 ± 5.74 years. The mean perforation size was 28.255 ± 9.16% while the mean air-bone gap was 28.000 ± 3.89 dB. It was concluded that the Pearson's correlation coefficient is directly correlated to perforation size and air-bone gap (r = 0.898, p <0.001). Further, hearing loss decreases with decreased middle ear volume and mastoid pneumatisation. Moreover, no change was seen in the mean air-bone gap according to the location of perforation. The hearing loss due to perforation of the tympanic membrane was correlated to the size of the perforation. Further, hearing loss decreases with reduced middle ear volume and mastoid pneumatisation. Size of perforation, Hearing loss, Air-bone gap, Oto-endoscopy, Conductive deafness, Mastoid pneumatisation.

Correlation of Air-Bone Gap on Pure Tone Audiometry with the Size of Perforation Assessed on Oto-Endoscopy.

To determine the correlation between the air-bone gap on pure tone audiometry with size of perforation oto-endoscopically. Study Design: A descriptive study. Place and Duration of the Study: Department of ENT - Head and Neck Surgery, Dow University of Health Sciences (DUHS), from February 2020 to August 2021. Methodology: A total of 43 patients with dry central pars tensa tympanic membrane perforation were diagnosed through oto-endoscopy during the study. The mean air-bone gap was calculated by assessing each air-bone gap through pure tone audiometry at different frequencies i.e., 250 Hz, 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz. Air-bone gap was found to be the average value of these frequencies. The photograph of the tympanic membrane was taken oto-endoscopically, and the ratio between size of the perforation to the entire area of the tympanic membrane was measured. During the course of the study, a total of 43 patients agreed to provide consent for this study. Out of the 43 patients, 16 (37.2%) were males and 27 (62.8%) were females. The age range was from 18 to 50 years with average age of 38.302 ± 5.74 years. The mean perforation size was 28.255 ± 9.16% while the mean air-bone gap was 28.000 ± 3.89 dB. It was concluded that the Pearson's correlation coefficient is directly correlated to perforation size and air-bone gap (r = 0.898, p <0.001). Further, hearing loss decreases with decreased middle ear volume and mastoid pneumatisation. Moreover, no change was seen in the mean air-bone gap according to the location of perforation. The hearing loss due to perforation of the tympanic membrane was correlated to the size of the perforation. Further, hearing loss decreases with reduced middle ear volume and mastoid pneumatisation. Size of perforation, Hearing loss, Air-bone gap, Oto-endoscopy, Conductive deafness, Mastoid pneumatisation.

Dorsal Carpal Artery Perforator Flaps: An Anatomical and Clinical Study.

Hand injuries pose challenges due to complexity and aesthetic-functional concerns. Dorsum of hand injuries are difficult to treat due to thin skin cover and increased propensity to exposure of underlying structures. Perforator-based flaps can provide better outcomes with minimal donor site morbidity. This study aims to bridge the gap in anatomical knowledge and explore the potential benefits of dorsal carpal artery perforator flap. A prospective study was done from July 2021 to June 2023, focused on study of dorsal carpal artery perforators on 12 fresh frozen cadaveric hands. Anatomical study involved injection of red latex into arteries at the wrist, followed by dissection and measurements. During the clinical phase, we used the inferences gained from the anatomical study to identify and mark perforator of dorsal carpal arteries. We performed V-Y advancement flap based on the DCPs in 5 patients who had dorsum of hand defects due to trauma. The study was carried out on 6 fresh frozen cadavers (12 hands). Anatomical findings revealed the anatomical location, caliber, and consistent number of dorsal carpal artery perforators supplying the dorsum of the hand arranged in 2 rows. Clinically, we applied this insight to create V-Y flaps in 5 patients with successful outcomes, thus, offering DCP-based flap as an alternative to distant flaps. DCP-based flaps offer an efficient solution for reconstructing proximal hand defects over the dorsum, with minimal complications, enhancing our understanding of hand reconstruction options. The study's comprehensive anatomical insights and clinical outcomes contribute to improving hand defect management and surgical techniques.

Myringoplasty: A comparison of inlay and underlay techniques

PurposeMyringoplasty aims to improve hearing and prevent otorrhea, making graft uptake rates and hearing crucial considerations. This study analyzed the factors associated with unsuccessful graft uptake and hearing improvement to guide the selection of optimal surgical approaches for myringoplasty. MethodsWe retrospectively reviewed 56 ears with chronic otitis media. All patients were followed up for >6 months after tympanic membrane closure surgery. We compared the underlay method using the transcanal approach with the inlay method using the retroauricular approach for myringoplasty in patients with chronic otitis media. The underlay and inlay methods were used for 23 and 33 ears, respectively. The primary outcomes were graft uptake rate and hearing improvement. Additionally, factors such as the location of tympanic membrane perforation, patient age, and the degree of mastoid development were evaluated. ResultsThe perforation rate was high when the transcanal underlay method was employed to repair perforations in the anterior inferior quadrant. Both the underlay and inlay methods significantly improved hearing. However, the success rate of the inlay method was lower. Within the cases performed using the inlay method, outcomes tended to be poorer in older age groups. There were no significant differences in surgical success rates related to mastoid development. ConclusionThe inlay method using the retroauricular approach is a favorable option for repairing perforations involving the anterior inferior quadrant. However, older patients presented lower rates of hearing improvement when the inlay method was used.

Local buckling behaviour of web perforated cold-formed steel lipped channel columns

To connect beams and bracings with storage rack uprights, closely spaced perforations are provided along the web, flanges, and rear flanges of uprights. These perforations can significantly lower the ultimate capacity of such compression members with the possible influence of its natural buckling modes. This capacity reduction can depend on various parameters such as (a) geometrical shape, proportioning of cross-section, and stiffeners; (b) perforation shape, size, spacing, and location; (b) slenderness of member, cross-section, and elements of cross-section; and (d) material properties. A thorough understanding of the influence of the above-mentioned factors is necessary for the accurate strength prediction of perforated Cold-formed steel (CFS) compression members. Even though the current design standards are updated for the accurate strength prediction of unperforated CFS compression members, they do not collectively account for the influence of all the aforementioned factors on the load-carrying capacity of the perforated CFS members, particularly for the local buckling capacity. Though the Direct Strength Method (DSM) of design is the most accepted method for accurate strength prediction of CFS members even for complex cross-sectional shapes, recent research on the strength evaluation of perforated CFS members using DSM has emphasized the need for refinement in DSM. The Modified Direct Strength Method (MDSM), which accounts for the simultaneous buckling of flanges and web, includes the cross-section aspect ratio and cross-section slenderness to predict more accurately the local buckling design strength. However, it was developed only for unperforated specimens. Hence, a systematic experimental and numerical investigation was done to understand the influence of the perforation in the local buckling behavior of the lipped channel section. In total, 14 specimens, including 2 unperforated and 12 web perforated CFS lipped channel stub columns were physically tested with fixed support conditions. The Finite Element Analysis using ABAQUS software was used to conduct an extensive parametric numerical study. The results were used to compare the strength curves of DSM and MDSM and the modification in the design curves has been proposed by considering the erosion in strength due to the presence of perforation.

The Local Rhombus-Shaped Flap-An Easy and Reliable Technique for Oncoplastic Breast Cancer Surgery and Defect Closure in Breast and Axilla.

Primarily, breast-conserving therapy is an oncological intervention, but eventually it is judged by its cosmetic result. Remaining cavities from tumor resection can promote seromas, delay healing and cause lasting discomfort. Additionally, volume loss, dislocation of nipple/areola and fat necrosis lead to (cosmetically) unfavorable results, aggravated by radiotherapy. Oncoplastic surgery can reduce these sequelae. A local flap that has rarely been used in breast cancer surgery is the Limberg rhombic flap. The tumor defect is planned as a rhombus. The sides of the rhombus are of equal length and ideally have an angle of 60° and 120°. The flap that closes the defect is planned as an extension of equal length of the short diagonal. The second incision of the flap is placed according to the defect angle of 60°, running parallel to the defect at the same length. This creates a second rhombus. The flap is transposed into the defect, and the donor area is primarily closed. It is axially perfused and safe with a 1:1 length-to-width ratio. Compared to local perforator flaps, defect closure is easily managed without microsurgical skills. In the breast, the flap can be used in volume replacement and volume displacement techniques as an all-layer flap to cover defects, or it can be deepithelialized and buried. In the axilla, it can cover full-thickness defects when skin is involved. The advantages of the rhombic flap are its safety and simplicity to add volume and close defects, thus reducing the complexity of oncoplastic surgery.

Prognostic Prediction of Multiterritory Flap: A Preliminary Clinical Study on the Classification of Priority Developing Artery and Arterial Anastomosis Utilizing Indocyanine Green Angiography.

Congestion and necrosis are frequent complications in multiterritory flaps. Indocyanine green angiography (ICGA) is a commonly utilized tool for evaluating blood flow and perforator location within the flap; however, there is currently no existing research investigating its potential to predict flap prognosis before surgery. The forehead skin of 50 surgical patients was assessed using preoperative ICGA, enabling observation and classification of the priority developing artery and arterial anastomosis among adjacent arterial perfusion territories during the arterial phase. Subsequently, 5 clinical cases of forehead flap transfer were studied to validate the classification method. First, the priority developing artery can be classified into 4 types and 5 subtypes, encompassing type Ⅰa: Bilateral ST-As equalization type (9/50), type Ⅰb: unilateral ST-A dominance type (11/50), type II: SOT-As dominance type (14/50), type III: unilateral ST-A plus SOT-A dominance type (6/50), and type IV: bilateral ST-As plus SOT-As equilibrium type (10/50). Second, arterial anastomosis can be divided into 5 types: type I: complete choke anastomosis type (13/50), type II: complete true anastomosis type (7/50), type III: central choke anastomosis type (10/50), type IV: bilateral choke anastomosis type (8/50), and type V: unilateral choke anastomosis type (12/50). Finally, the clinical flap outcomes showed that the ICGA classification could serve as a good prognostic indicator. The hemodynamic classification of priority developing artery and arterial anastomosis employed by ICGA has the potential to predict flap prognosis and offer valuable insights for preoperative design and perioperative treatment strategies. More sample size is needed to optimize and validate this classification.

Cyanoacrylate glue: An emerging alternative for sealing of corneal perforation

Maintaining corneal wound integrity is an important goal in corneal perforations resulting from either traumatic or non- traumatic etiology. Tissue adhesives (TA’s) are group of synthetic or naturally occurring compounds, which helps in wound reconstruction and have emerged as alternatives to conventional sutures. Our study aims to evaluate the efficacy N- butyl cyanoacrylate TA in corneal perforations following infectious keratitis by assessment of its morphological and functional outcome. A prospective observational study conducted over a period of 6 months on 42 eyes of 42 patients with perforated corneal ulcer, fulfilling the inclusion criteria, presenting to our outpatient department. A standard technique was used to apply TA to the site of perforation under topical anaesthesia in all patients and they were followed-up for a period of 6 weeks. Data analysis was done using SPSS software (Version 22) and P value calculated by Pearson Chi-square test (Fisher exact test). P- value &amp;#60; 0.05 was considered statistically significant. Morphological outcome in this study showed statistically significant relationship with causative organism and size of the perforations (p&amp;#60;0.05). The functional outcome showed statistically significant relationship with location of perforation, duration of symptoms and duration of stay of glue (p&amp;#60;0.05). TA’s works well when the corneal perforation is &amp;#60;1.5 mm in diameter. The morphological outcome of TA depends upon etiology, size of perforations and complications significantly. Functional outcome of tissue adhesive shows significant association with location of perforation, duration of symptoms and stay of glue.

Evaluation of Maxillary Sinus Septa Using Cone Beam Computed Tomography (CBCT): A Retrospective Study.

Maxillary sinus septa, which are bony structures dividing the sinus cavity, can pose challenges during sinus lift or implant surgeries by potentially causing perforation of the Schneiderian membrane. This study aimed to estimate the prevalence, height, location, orientation, and risk of perforation of the maxillary sinus septa using cone beam computed tomography (CBCT). This retrospective, cross-sectional study utilized CBCT (NewTom CBCT machine, of which the scan parameters were 90 KvP, 8 mAs, and 14 s exposure with a field of view (FOV) of 8×8 cm and a 0.2 mm3 voxel size) images of 300 maxillary sinuses from patients aged >18 years, obtained from Swami Devi Dyal Hospital and Dental College in Panchkula, India. Scans were analyzed for the presence, height, location, orientation, and risk of septal perforation. The data were categorized based on age, sex, and dentition status. Statistical analyses were performed to assess the prevalence, configuration, and risk factors. The prevalence of maxillary sinus septa was 21.33%, with the majority showing a single septum (90.63%). Septa were predominantly found in the middle region (48.44%), with bucco-palatal orientation (93.75%) being more common than anteroposterior. The mean septa height was 6.16 mm. The perforation was classified as moderate (48.4%), low (46.8%), or high (4.6%). Class III septa were associated with the highest risk of perforation. This study highlights a significant prevalence of maxillary sinus septa with variations in height, orientation, and location. The risk of perforation varies with the septa configuration and orientation. CBCT is essential for identifying these anatomical features to minimize surgical complications and to guide preoperative planning.

The largest perforator of DIEP flap has a higher rate of continuity with the superficial inferior epigastric artery

In deep inferior epigastric artery (DIEA) perforator (DIEP) flap breast reconstruction, the network with the superficial inferior epigastric artery (SIEA) is key to achieving stable subcutaneous blood flow to the flap. This study investigated how the diameter and location of the DIEA perforator affect continuity with the SIEA. A retrospective analysis of 94 specimens from 47 patients who underwent DIEA perforator flap breast reconstruction was performed. Relationships between the diameter and location of the DIEA perforator and its continuity with the SIEA were examined on preoperative multi-slice computed tomography. The largest DIEA perforator on each specimen showed continuity with the SIEA in 94%, significantly more than the second (80%; p=0.027) or third largest perforator (76%; p=0.005). Medial perforators from 3cm above to 3cm below the umbilicus showed more continuity with the SIEA than lateral perforators (p=0.008). Selection of the largest perforator of DIEP flap is advantageous in terms of continuity with the SIEA. Also, near the umbilicus, medial perforators communicate with the SIEA more than lateral perforators.

Efficacy and safety of a self-expandable retainer in endoscopic ear surgery.

During endoscopic ear surgery (EES), it is important to maintain a clear view of the endoscopic camera to achieve a clean field. In this study, a self-expandable external auditory canal (EAC) retainer was developed to enable a more efficient and safer EES. This study aimed to evaluate the retainer's efficacy and safety in EES. Among adult patients scheduled for endoscopic tympanoplasty, 50 participants were recruited. They were assigned to either the retainer or control group in a 1:1 ratio. The anatomical characteristics, number of endoscopic cleanings during surgery, surgeon's satisfaction, and other factors were evaluated. No differences were observed in the surgical direction, EAC size measured on preoperative temporal bone computed tomography scans, location and size of tympanic membrane perforation, or bleeding degree between the two groups. When comparing the surgical time, including retainer insertion and removal, the time was similar between groups (retainer group, 35min; control group, 33.2min). The frequency of endoscopic cleaning per minute was statistically significantly lower in the retainer group than in the control group (0.18 times per minute, p = 0.048). No side effects, including sensory abnormalities or allergic reactions, were reported in any patient who used the retainer. A reduction in unnecessary endoscopic cleaning during EES was observed while using the self-expandable retainer, leading to increased surgeon satisfaction and efficiency. Furthermore, as a safe method without side effects, the retainer could be widely used to various indications for EES beyond tympanoplasty.

HoloDIEP-Faster and More Accurate Intraoperative DIEA Perforator Mapping Using a Novel Mixed Reality Tool.

Microsurgical breast reconstruction using abdominal tissue is a complex procedure, in part, due to variable vascular/perforator anatomy. Preoperative computed tomography angiography (CTA) has mitigated this challenge to some degree; yet it continues to pose certain challenges. The ability to map perforators with Mixed Reality has been demonstrated in case studies, but its accuracy has not been studied intraoperatively. Here, we compare the accuracy of "HoloDIEP" in identifying perforator location (vs. Doppler ultrasound) by using holographic 3D models derived from preoperative CTA. Using a custom application on HoloLens, the deep inferior epigastric artery vascular tree was traced in 15 patients who underwent microsurgical breast reconstruction. Perforator markings were compared against the 3D model in a coordinate system centered on the umbilicus. Holographic- and Doppler-identified markings were compared using a perspective-corrected photo technique against the 3D model along with measurement of duration of perforator mapping for each technique. Vascular points in HoloDIEP skin markings were -0.97 ± 6.2 mm (perforators: -0.62 ± 6.13 mm) away from 3D-model ground-truth in radial length from the umbilicus at a true distance of 10.81 ± 6.14 mm (perforators: 11.40 ± 6.15 mm). Absolute difference in radial distance was twice as high for Doppler markings compared with Holo-markings (9.71 ± 6.16 and 4.02 ± 3.20 mm, respectively). Only in half of all cases (7/14), more than 50% of the Doppler-identified points were reasonably close (<30 mm) to 3D-model ground-truth. HoloDIEP was twice as fast as Doppler ultrasound (76.9s vs. 150.4 s per abdomen). HoloDIEP allows for faster and more accurate intraoperative perforator mapping than Doppler ultrasound.

Role of Tympanometric Ear Canal Volumes in Determining Outcome of Myringoplasty in Chronic Suppurative Otitis Media Patients.

Middle ear aeration is a predictive indicator of myringoplasty's successful outcome and tympanometric ear canal volume is a novel investigation that can estimate the volume of middle ear cleft and mastoid air cells. Our aim of this study is to determine the role of tympanometric ear canal volume on myringoplasty outcome in Chronic Suppurative Otitis Media Patients. Prospective analysis involving 50 patients of CSOM was performed on patients undergoing myringoplasty from April 2022 to December 2023. Smokers, Patients with squamosal COM, Bilateral COM, Otitis Externa, and Revision surgery were excluded from the study. The successful outcome of surgery was defined as no tympanic membrane perforation on postoperative follow-up. Analysis was carried out using SPSS. V. 25 and P-value less than 0.05 was considered significant. A total of 50 patients were included in the study with a mean age of 24.4 ± 8.965 and male predominance. Overall graft uptake was 64%. Graft uptake had no significant statistical correlation with age, gender, type, location, or size of perforation. However, there is a significant effect of tympanometric ear canal volume of pathological ear and interaural tympanometric ear canal volume difference on graft uptake with p-values of 0.023 and 0.033 respectively. Tympanometric ear canal volume can predict middle ear aeration and the higher the interaural tympanometric canal difference more are the chances of successful graft uptake.

Posterior Tibial Artery Perforator Based Propeller Flap for Reconstruction of 143 Skin and Soft Tissue Defect Around Ankle Joint

Background: Soft tissue coverage of distal leg and ankle region represents a challenge and such defect usually requires a free flap. However, this needs facility of microsurgery, may lead to donor site morbidity and is time consuming. With the introduction of perforator flap, management of small and medium size defects of distal leg and ankle region is easier, less time consuming, and with minimal donor site morbidity. When local perforator flap is designed as propeller and rotated to 180-degree, donor site can be closed primarily and increases the distance crossed by flap, thus increasing versatility. Objectives: To observe the outcome of soft tissue coverage of defects around ankle joint by posterior tibial artery perforator based propeller flaps. Methods: This was a prospective type of observational study carried out on 20 patients with skin and soft tissue defects in and around ankle joint for a period of 14 months in the Department of Burn and Plastic Surgery, Dhaka Medical College and Hospital. Results: Among 20 cases 17 were male and 3 females; age ranged from 11 to 60 years. Post operative outcome of flap were excellent in 11 cases, good in 6 cases, poor in 3 cases as per defined criteria. Uneventful outcome was observed in 14 cases and minor complications were observed in 5 cases; and total flap loss occurred in 1 case which required revision surgery. Conclusions: Perforator flap provides adequate soft tissue coverage for small &amp; medium size wound around ankle. It is an easy, reliable &amp; effective procedure with reasonable outcome. J Dhaka Med Coll. 2022; 31(2) : 243-250

Clinical Outcomes of Endoscopic Butterfly Inlay Cartilage Myringoplasty.

To review a 3-year case series of endoscopic butterfly inlay cartilage myringoplasty performed by a single surgeon (W.S.K.) and analyze the clinical surgical outcomes. Retrospective study. Tertiary care academic center. We enrolled 60 ears with tympanic membrane (TM) perforation, receiving endoscopic inlay butterfly myringoplasty between 2019 and 2022. We reviewed patients' demographics, size and location of TM perforation, operation time, complications, and postoperative pain evaluated by the numerical rating scale (NRS). We analyzed the graft uptake success rate in 5 weeks and the perforation closure rate in 4 months after surgery. We also compared the air-bone gap (ABG) before and after the surgery. Among the 60 ears included, the mean age was 57.0 years, and 78.3% (47 of 60) had small perforations. The average operation time was 48.9 ± 11.5 minutes, and the postoperative NRS was 2.0 ± 1.6. The immediate graft uptake success rate evaluated at postoperative 5 weeks was 96.7% (58 of 60), with myringitis occurring in three ears. Except for 11 patients lost to follow-up, the perforation closure rate evaluated at postoperative 4 months was 100% (49 of 49). The mean ABG significantly improved from preoperative status (8.87 ± 5.51 dB HL) to postoperative 4 months (6.22 ± 6.03 dB HL) ( p = 0.019). A single surgeon's success rate for endoscopic butterfly inlay cartilage myringoplasty was almost 100%. This surgical procedure is safe and effective, with a high graft success rate.

The Analysis of Permeability Influence on CO2 Plume based on Reservoir Simulation

Abstract Permeability is critical in site characterization and geoscience studies for carbon capture and storage projects. There is significant uncertainty of CO2 movement in the subsurface caused by permeability. This study aims to analyze the influence of permeability on the movement of CO2 plumes using a synthetic single-porosity model based on reservoir simulation. By simplifying geomechanics, employing tornado experimental design, as well as utilizing Pearson and Spearman correlations from 30,000 neural network proxy models based on Latin Hypercube and Monte Carlo experimental design, this research successfully explains the impact of permeability on CO2 movement. The reservoir can withstand pressures up to 6500 psi without rock failure. The total CO2 injection with a 90% probability is ∼1.3 TSCF equivalent, with an injection rate of 30 MMSCFD, optimized for a duration of 120 years. Initially, the CO2 movement tends to be upward during injection due to gravitational effects, but over time, it tends to move laterally. Vertical permeability exhibits a negative correlation with total CO2 injection, lateral distribution of CO2 plumes, and CO2 solubility in water. On the other hand, horizontal permeability shows a positive correlation with total CO2 injection. Factors such as perforation location and layer thickness also influence the extent of permeability’s role. However, the lateral and vertical movement of CO2 in this study has not been fully identified, and more complex quantification formulas are needed in commercial simulators. Despite the limitations in data and computational resources, this research successfully explains the movement of CO2 plumes and highlights the importance of other factors such as porosity, perforation location, layer thickness, among others. The recommendations of this study include the use of more complex quantification formulas to model the movement of CO2 plumes, along with increasing the complexity of the model.

Effectiveness of the proximal medial branch in DIEP flaps for breast reconstruction using Hartrampf zone IV

BackgroundWhen performing breast reconstruction using a deep inferior epigastric artery perforator (DIEP) flap, including Hartrampf zone IV, the bipedicled DIEP flap has been argued to be necessary to ensure stable perfusion. However, a proximal medial branch (PMB), which is the most proximal perforator of the deep inferior epigastric artery, may make it possible to obtain adequate perfusion in a unilateral DIEP flap. This study aimed to clarify the detailed anatomical characteristics of PMB and its potential clinical application in breast reconstruction. MethodsThis retrospective study was conducted on breast reconstruction using the DIEP flap between May 2020 and July 2023. Data on PMB anatomy were collected from preoperative contrast-enhanced computed tomography angiography, and contralateral perfusion of the flap was estimated using intraoperative indocyanine green angiography. ResultsThe PMB was present in approximately 85% of cases, arising near the lateral border of the rectus abdominis, branching caudomedially in over half of the cases, and perforating 2.3cm laterally and 8.8cm caudally on average from the umbilicus. The average perfusion area of both zones II and IV significantly expanded to 96.5% and 74.2%, respectively, when the PMB was included in the DIEP flap, and 9 of 22 cases showed contrast extending to the entire zone IV. ConclusionsThe use of the DIEP flap with PMB is a good option for substantial-volume breast reconstruction. When utilizing the PMB, it is important to consider its specific anatomy, location of the main perforator, and pedicle length.

Perfusion area versus volume of the DIEP flap: A multivariable analysis of perforator and flap characteristics for estimation of perfusion area and volume

BackgroundThe extent of perfusion of a deep inferior epigastric artery perforator (DIEP) flap is a primary concern for surgeons. This study aimed to determine whether the flap area or volume can be estimated using perforator and flap characteristics. MethodsIntraoperative flap perfusion was assessed using indocyanine green angiography in patients who underwent DIEP flap breast reconstruction between November 2018 and February 2023. The area perfused by a single dominant perforator was delineated on the surface of the flap and measured using the ImageJ software. Multiple linear regression analysis was conducted to estimate the ‘perfusion ratio,’ defined as the perfused area divided by the total flap area. Potential predictor variables included flap size (cm2), flap thickness (mm), perforator diameter (mm), perforator rows (medial/lateral), vertical location of perforator (at or above/below the umbilicus), and perforator eccentricity (vertical distance from upper flap margin to perforator, cm). ResultsIn total, 101 patients were included in this analysis. The mean ‘perfusion ratio’ was 67.8% ± 11.5%, predicted by perforator diameter (p = 0.022) and vertical location below umbilicus (p < 0.001) with positive correlations and negatively correlated with flap thickness (p = 0.003) in the multivariable analysis. Both perfusion area and weight were predicted by perforator diameter, vertical location of perforator, flap size, and flap thickness (p < 0.001). The coefficient of determination (adjusted R2) for prediction of perfusion weight was higher than that for the perfusion area (75.5% vs. 69.4%). ConclusionsFlap volume, rather than area, is determined by a perforator of a given diameter and location.

TFL Perforator Flap Complementing and Completing the ALT-AMT Flap Axis.

Background Anterolateral thigh (ALT) flap is the most common soft tissue flap used for microvascular reconstruction of head and neck. Its harvest is associated with some unpredictability due to variability in perforator characteristics, injury or unfavorable configuration for complex defects. Anteromedial thigh (AMT) flap is an option, but the low incidence and thickness restrict its utility. Tensor fascia lata (TFL) perforator (TFLP) flap is an excellent option to complement ALT. Its perforator is consistent, robust, in vicinity, and lends itself with the ALT perforator. Methods This study was an analysis of 29 cases with a free flap for head neck reconstruction with an element of TFLP flap from July 2017 to May 2021. Results All cases were primarily planned for an ALT reconstruction. There was absence of the ALT perforator in 16 cases but a sizable TFL perforator was available. In 13 cases, the complex defect warranted use of both ALT plus TFL in a conjoint (5), chimeric (5), and multiple (3) free flaps manner. Most common perforator location was septocutaneous between the TFL and gluteus medius. There was complete flap loss in two cases and partial necrosis in two. No adjuvant therapy was delayed. Conclusion TFLP can reliably complement the ALT/AMT axis. Chimeric ALT-TFL can be harvested for large, complex, multicomponent, and multidimensional defects.