Perforation Length Research Articles

Experimental Study of Fracture Propagation Mechanisms by Oriented Perforation Technology for SRV Fracturing

Due to the growing importance of shale oil and gas resources, more effective techniques to develop unconventional reservoirs are strongly required. In this paper, a new volumetric fracturing measure for unconventional resources based on oriented perforation technology has been introduced. Moreover, this innovative approach was validated through a series of laboratory experiments varying the parameters of physical models, such as perforation azimuth, perforation length and horizontal stress difference. The results showed that the artificial hydraulic fracture formed by using oriented perforation technology was not a satisfactory straight dual-wing fracture, instead, it was a bent dual-wing crack like “S” or “X”, which could significantly increase the stimulated reservoir volume. The perforation azimuth and horizontal stress difference were the primary factors that affected the formation of multi fractures. The reorientation path was extended with the increasing of the oriented perforation azimuth angle, but decreased with the increasing of horizontal stress difference. In addition, increasing the perforation length could greatly decrease the initiation pressure. Therefore, the oriented perforation technology could be as a powerful way to accelerate the exploitation of the unconventional reservoirs.

Natural-hydraulic fracture interaction: Microseismic observations and geomechanical predictions

Natural fractures can reactivate during hydraulic stimulation and interact with hydraulic fractures producing a complex and highly productive natural-hydraulic fracture network. This phenomenon and the quality of the resulting conductive reservoir area are primarily functions of the natural fracture network characteristics (e.g., spacing, height, length, number of fracture sets, orientation, and frictional properties); in situ stress state (e.g., stress anisotropy and magnitude); stimulation design parameters (e.g., pumping schedule, the type/volume of fluid[s], and proppant); well architecture (number and spacing of stages, perforation length, well orientation); and the physics of the natural-hydraulic fracture interaction (e.g., crossover, arrest, reactivation). Geomechanical models can quantify the impact of key parameters that control the extent and complexity of the conductive reservoir area, with implications to stimulation design and well optimization in the field. We have developed a series of geomechanical simulations to predict natural-hydraulic fracture interaction and the resulting fracture network in complex settings. A geomechanics-based sensitivity analysis was performed that integrated key reservoir-geomechanical parameters to forward model complex fracture network generation, synthetic microseismic (MS) response, and associated conductivity paths as they evolve during stimulation operations. The simulations tested two different natural-hydraulic fracture interaction scenarios and could generate synthetic MS events. The sensitivity analysis revealed that geomechanical models that involve complex fracture networks can be calibrated against MS data and can help to predict the reservoir response to stimulation and optimize the conductive reservoir area. We analyzed a field data set (obtained from two hydraulically fractured wells in the Barnett Formation, Tarrant County, Texas) and established a coupling between the geomechanics and MS within the framework of a 3D geologic model. This coupling provides a mechanics-based approach to (1) verify MS trends and anomalies in the field, (2) optimize conductive reservoir area for reservoir simulations, and (3) improve stimulation design on the current well in near-real-time and well design/stimulation for future wells.

Thoracodorsal artery perforator flap: Indeed a versatile flap.

Introduction:The thoracodorsal artery perforator (TDAP) flap has emerged as one of the ideal perforator flaps. We, hereby, describe its versatility in indications (free/pedicled), methods of harvest (patient position and paddle orientation) and perforator consistency.Materials and Methods:We have performed a total of six TDAP flaps-five free and one pedicled, over a period of 1-year from March 2014 to February 2015 at a single centre. Our indications have been: Reconstruction of oral cavity, breast and upper and lower extremities.Results:We had neither any failures nor any re-explorations. The average perforator length is about 6 cm and the pedicle length can be extended to 12-14 cm by including the thoracodorsal artery. There is inconsistency in perforator position; however, the presence of a perforator is certain. It can be harvested in lateral, prone or supine position, thus, does not require any position change allowing a two-team approach to reconstruction. The paddle can be oriented vertically or horizontally, both healing with scars in inconspicuous locations. Apart from providing a good colour match for extremities, this flap can be thinned primarily.Conclusion:The versatility of TDAP has several advantages that make it a workhorse flap for most reconstructions requiring soft tissue cover. Further, the ease of harvest makes it a good perforator flap for beginners. Its use in chimerism with the underlying latissimus dorsi muscle provides reconstruction for coverage and volume replacement.

Assessing the Needs to Incorporate Completion Details in a Petroleum Reservoir Simulation Model

Most of the current research and commercial reservoir simulators lack the capability to handle complex completion details like perforation tunnels in a simulation study. In most common applications, the simplified handling of completion complexity in reservoir simulations is not expected to introduce significant error in simulation results. However, it has been found that under certain circumstances, especially in high rate wells that have become more and more common in deepwater oil and profilic gas development, exclusion of the complex completion details in a reservoir simulation model would lead to nontrivial errors. New equations have been proposed to assess the needs to incorporate completion details in a reservoir simulation study based on the understanding of the fluid flow in a formation, the fluid flow along a wellbore and the fluid flow through perforation tunnels if exist. A series of sensitivity studies with different completion options under different flow and reservoir environments has been conducted to provide some guidance to improve well performance prediction through reservoir simulation. Impacts of key parameters like perforation density, perforation diameter, perforation length, wellbore length, borehole diameter, well completion configuration, well placement, reservoir permeability, reservoir heterogeneity, pressure drawdown, etc, have also been investigated.

Study on Influence of Mud Pollution on Formation Fracture Pressure

The mud pollution may change the mechanical properties of rock during oil and gas drilling process, which affects the prediction of fracture pressure, leads to the failure of hydraulic fracturing treatment. Therefore, it is necessary to study influence of mud pollution on formation fracture pressure to improve the forecasting accuracy. The mud pollution has influences on the modulus of elasticity and the Poisson’s ratio of rock by the mud pollution experiment, the core microstructure is observed around the mud pollution. Based on the experiment and research, the effects of mud pollution on the fracturing pressure are studied by finite element software system ANSYS, the factors such as pollution depth, perforation length and Poisson’s ratio of polluted area are taken into account. The result of the experiment indicated that the modulus of elasticity of rock is reduced and the Poisson’s ratio of rock is increased by the mud pollution. Through computing and analyzing, it can be concluded that increases in pollution depth and Poisson’s ratio can lead to a vast increase in formation fracturing pressure. A calculation example is presented and the results show that the results of this research can provide valuable guidance to the designers of hydraulic fracturing treatment.

Perforator flaps in hand reconstruction: the effect of blood vessel twisting.

Background and aimsPerforator flaps increasingly find acceptance and use in hand reconstructive surgery. A propeller flap is an island flap that moves from one orientation to another by rotating around its vascular pedicle. It is now possible to design propeller flaps based on a single perforator, so-called “perforator-based propeller flaps,” but they are more prone to vascular impairment when twisted more than 90°.MethodsWe present a prospective study conducted in the Plastic and Reconstructive Surgery Department of the Rehabilitation Hospital over 17 months. All perforator-based propeller flaps that were used for hand reconstruction were analyzed. The parameters studied included the size and location of the defect, the size and shape of the flap, the perforator (length and location) that was used, the degree of twisting of the perforator, the degree of perforator dissection, the management of the donor site, and flap survival area.ResultsIn this study we investigated the circulatory impairment induced by twisting of the pedicle on a true perforator flap. All flaps survived completely with the exception of partial skin necrosis in few cases. Some of these cases required debridement and skin grafting.ConclusionsPerforator-based propeller flaps provide a reliable option for covering small- to medium-size hand complex tissue defects. They have the advantages of using similar tissues in reconstruction, not damaging another area, they do not require main vessels sacrifice, and the donor site can be generally directly closed.

The effect of a perforated plate on the propagation of laminar hydrogen flames in a channel – A numerical study

Laminar hydrogen flame propagation in a channel with a perforated plate is investigated using 2D reactive Navies-Stokes simulations. The effect of the perforated plate on flame propagation is treated with a porous media model. A one step chemistry model is used for the combustion of the stoichiometric H2–air mixture. Numerical simulations show that the perforated plate has considerable effect on the flame propagation in the region downstream from the perforated plate and marginal effect on the upstream region. It is found to squeeze the flame front and result in a ring of unburned gas pocket around the flame neck. The resulting abrupt change in flow directions leads to the formation of some vortices. Downstream of the perforated plate, a wrinkled “M”-shape flame is observed with “W” shape flame speed evolution, which lastly turns back to a convex curved flame front. Parametric studies have also been carried out on the inertial resistance factor, porosity, perforated plate length and its location to investigate their effects on flame evolution. Overall, for parameter range studied, the perforated plate has an effect of reducing the flame speed downstream of it.

Esophagectomy in esophageal perforations: an analysis.

This study aimed to study the factors that are associated with urgent esophagectomy for the treatment of esophageal perforations and the impact of this therapy. A retrospective review of all esophageal perforations treated at a tertiary care hospital from January 1984 to January 2012 was performed. Compiling demographics, cause and site of perforations, time to presentation, comorbidities, radiological tests, the length of perforation, the hemodynamic status of the patient, type of treatment required, and outcomes were performed. Univariate, multivariate, and Cox regression analyses were conducted. Of 127 cases of esophageal perforation, it was spontaneous in 44 (35%), iatrogenic in 53 (44%), foreign body ingestion in 22 (17%), and traumatic perforation in 7 (6%) cases. Overall, 85 of the 127 (67%) patients were managed operatively, 35 (27.6%) patients were treated conservatively, and 7 (6.3%) patients were treated by endoscopic stent placement. Of the 85 patients who were managed operatively, 21 (16.5%) required esophagectomies, 13 (15.3%) had esophagectomy with immediate reconstruction, 5 (5.9%) patients had esophagectomy followed by delayed reconstruction, and 3 (3.5%) patients failed primary repair and required an esophagectomy as a secondary definitive procedure. Multivariate analysis revealed that esophagectomy in esophageal perforations was associated with the presence of benign or malignant esophageal stricture (P = 0.001) and a perforation >5 cm (P = 0.001). Mortality was mainly associated with the presence of a benign or malignant esophageal stricture (P = 0.04). The presence of pre-existing benign or malignant stricture or large perforation (>5 cm) is associated with the need for an urgent esophagectomy with or without immediate reconstruction. Performing esophagectomy was not found to be a significant prognosticator for mortality.

The microvascular anatomy of superior and inferior gluteal artery perforator (SGAP and IGAP) flaps: a fresh cadaveric study and clinical implications.

Our study aimed to highlight anatomical similarities, differences, and variations in the microvascular anatomy between superior and inferior gluteal artery perforator (SGAP and IGAP) flaps. Thirty gluteal flaps (15 SGAP and 15 IGAP) were studied on 22 adult fresh cadavers. We recorded the number and location of perforators, the characteristics of the main perforator (course, length, and diameter at the level of division at the greater sciatic foramen), and the anatomical variations of the submuscular venous plexus. The mean number of perforators was similar in both flaps (n = 7). We found a statistically significant difference in the total length of the vascular pedicle between SGAP (mean = 9.80 cm) and IGAP (mean = 13.36 cm) flaps, which correlated strongly with the difference in the intramuscular length (mean difference = 3.40 cm) of the perforator. There was no statistically significant difference in the diameter of the superior and inferior gluteal vessels at the point of pedicle division. The complex submuscular venous plexus, which is typically found on SGAP flaps deep to the sacral fascia, was never encountered on IGAP flaps. Perforators originating from the inferior gluteal artery were found on the lower half of five superior gluteal flaps. These were dominant perforators in two cases. We also report a rare anatomical communication between superior and inferior gluteal vessels deep to the piriformis muscle and a case of atheromatous disease of the inferior gluteal artery. Our findings are highly relevant to clinical practice and contribute to the understanding of the vascular anatomy of SGAP and IGAP flaps and the successful use of these challenging flaps. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Reconstruction of a Posterior Trunk Defect using a Pedicled Dorsolateral Posterior Intercostal Artery Perforator Flap.

Reconstruction of a Posterior Trunk Defect using a Pedicled Dorsolateral Posterior Intercostal Artery Perforator Flap.

Reconstruction of the zygomatic cheek defects using a flap based on the pretragal perforator of the superficial temporal artery

The aim of this study was to create a new flap based method for zygomatic cheek defect reconstruction using the pretragal perforator from the superficial temporal artery. Ten fresh cadavers were dissected after vascular injection to study pretragal perforator distribution, length, and diameter. Twelve clinical cases of zygomatic cheek defects were reconstructed using pretragal perforator flaps. According to the location of the perforator that was preoperatively probed using an ultrasound Doppler blood flow detector and the zygomatic cheek defect condition, size, and distance from the distal border to the tragus and the flabby surrounding skin, we designed a spindle-shaped longitudinal flap in the preauricular region based on the pretragus. The flap was raised superficially to the superficial musculoaponeurotic system from the caudal border incised primarily to the cephalic border to create the perforator flap. The flap was sutured to the defect and the donor site was closed. Cadaver dissection showed a quite constant perforator given off by the superficial temporal artery or its auricular branches with an appearance rate of 85% anterior to the tragus. The average perforator length was 18.3 mm (range, 11.2-24.2 mm). The average perforator diameter was 0.65 mm (range, 0.4-1.15 mm). A total of 12 clinical cases were available for 6-12 month postoperative follow-up. Favorable survival, primary closure, and esthetic results were achieved without any complications. Zygomatic cheek defect reconstruction using the above-mentioned flap can achieve satisfactory esthetic and functional results and boasts a simple design, convenient procedure, reliable blood supply, and concealed donor site incision.

Enhancement of natural convection heat transfer from horizontal rectangular fin arrays with perforations in fin base

The overall convection heat transfer coefficients for long horizontal rectangular fin arrays are low because the surfaces in the inner region are poorly ventilated. In this study, we introduce perforations through the fin base to improve ventilation with cold air from below the fin base. Aluminum fin arrays with length L = 380 mm or 104 mm, fin height H = 38 mm, fin thickness tf = 1 mm, and fin spacing S = 10 mm are analyzed numerically with a temperature difference of 55 K between the fin base and the surroundings. Since the flow associated with horizontal rectangular fin arrays longer than about 100 mm tends to be unsteady, an unsteady model is adopted. In the main part of the present study, we analyze a single channel with multiple equal-length, equally spaced rectangular perforations which cover the full width of the fin spacing and have a total perforation length of L/2 or L/4. In addition, a multi-channel analysis is conducted for a selected fin array configuration with the uniform heat applied on the bottom surface at the middle part and longitudinal perforations arranged on the fin base outside the heated region. The perforations, especially located in the inner region, improve ventilation and heat transfer performance significantly. The patterns with more distributed shorter perforations exhibit better improvements. The overall heat transfer coefficients can be more than twice as large as that without perforations for long fin arrays. The flow fields and the longitudinal distributions of the height-averaged local heat flux from fin surface are analyzed to describe the effects of fin-base perforations.

Simulating Multizone Fracturing in Vertical Wells

Numerous multizone multistage hydraulic fracturing treatments are now being executed in low permeability oil and gas fields around the world. Due to the limited access to the subsurface, post-treatment assessments are mainly limited to few techniques such as tiltmeter, microseismic, and tracer-logs. The first two techniques are mainly used to determine fracture extension; however, fracture height and fracture initiation at all perforation clusters could only be confirmed through radioactive tracer logs or detailed pressure analysis. In this paper, we consider real examples from a field from Central America and investigate potential problems that led to the limited generation of fractures in multizone treatments. For instance, some of the postfrac radioactive logs show very low concentration of tracers at some perforated zones in comparison with other zones. On the other hand in some cases, tracer logs indicate the presence of tracers in deeper or shallower zones. Different reasons could cause fracture growth in nonperforated zones, including but not limited to: perforation design problems, casing/cement integrity problems, lack of containment, instability of fracture growth in one or some of the zones, and finally making a mistake in selecting lithology for fracturing. In this paper, some of these issues have been examined for a few sample wells using treatment pressure data, petrophysical logs, and postfrac tracer logs. Some recommendations in designing the length and arrangement of perforations to avoid these problems in future fracturing jobs are provided at the end of this paper.

Numerical Mode Matching Approach for Acoustic Attenuation Predictions of Double-Chamber Perforated Tube Dissipative Silencers with Mean Flow

The transfer matrix method (TMM) based on numerical mode matching (NMM) approach is developed to investigate the acoustic behavior of double-chamber perforated tube dissipative silencer with mean flow. The present method is verified by comparing the transmission loss (TL) predictions and experimental data. Then the effects of mean flow, perforated tube offset and lengths of perforations are studied computationally. As the Mach number increases, the TL of dissipative silencer is lowered at most frequencies. The perforated tube offset may change the acoustic behavior in the mid-high frequency range. Increasing the total length of perforations increases TL at the mid-high frequencies.

Endoscopic submucosal dissection vs endoscopic mucosal resection for early gastric cancer: A meta-analysis.

To compare endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) for early gastric cancer (EGC). Computerized bibliographic search was performed on PubMed/Medline, Embase, Google Scholar and Cochrane library databases. Quality of each included study was assessed according to current Cochrane guidelines. Primary endpoints were en bloc resection rate and histologically complete resection rate. Secondary endpoints were length of procedure, post-treatment bleeding, post-procedural perforation and recurrence rate. Comparisons between the two treatment groups across all the included studies were performed by using Mantel-Haenszel test for fixed-effects models (in case of low heterogeneity) or DerSimonian and Laird test for random-effects models (in case of high heterogeneity). Ten retrospective studies (8 full text and 2 abstracts) were included in the meta-analysis. Overall data on 4328 lesions, 1916 in the ESD and 2412 in the EMR group were pooled and analyzed. The mean operation time was longer for ESD than for EMR (standardized mean difference 1.73, 95%CI: 0.52-2.95, P = 0.005) and the "en bloc" and histological complete resection rates were significantly higher in the ESD group [OR = 9.69 (95%CI: 7.74-12.13), P < 0.001 and OR = 5.66, (95%CI: 2.92-10.96), P < 0.001, respectively]. As a consequence of its greater radicality, ESD provided lower recurrence rate [OR = 0.09, (95%CI: 0.05-0.17), P < 0.001]. Among complications, perforation rate was significantly higher after ESD [OR = 4.67, (95%CI, 2.77-7.87), P < 0.001] whereas the bleeding incidences did not differ between the two techniques [OR = 1.49 (0.6-3.71), P = 0.39]. In the endoscopic therapy of EGC, ESD showed a superior efficacy but higher complication rate with respect to EMR.

Research of Interlayer Interference and Development Strategy of Multilayer Commingled Production Gas Reservoir

Sebei gas field is featured with the characteristics of the shallow-buried gas reservoir, long gas containing well section, multilayer gas reservoirs beds, the complicated gas/water contact distribution, the water produced obviously, sands produced frequently from the gas wells and the multi-layers gas reservoir extracted unbalancedly in the developing process. For these reasons, the paper proposed the method that interlayer interference coefficients are defined with statistical function. Combined with the data of the sand-layers profile test, the effects of the numbers of different sand-lays, the perforated thickness, the perforated interval length and permeability contrast on the interlayer interference are evaluated and these permeability parameters are optimized.

Perforation optimization of hydraulic fracturing of oil and gas well

Considering the influences of fluid penetration, casing, excavation processes of wellbore and perforation tunnels, the seepage-deformation finite element model of oil and gas well coupled with perforating technique is established using the tensile strength failure criterion, in which the user-defined subroutine is developed to investigate the dynamic evolvement of the reservoir porosity and permeability. The results show that the increases of perforation angle and decreases of perforation density lead to a higher fracture initiation pressure, while the changes of the perforation diameter and length have no evident influences on the fracture initiation pressure. As for initiation location for the fracture in wellbore, it is on the wellbore face while considering the presence of the casing. By contrast, the fractures firstly initiate on the root of the tunnels without considering casing. Besides, the initial fracture position is also related with the perforation angle. The fracture initiation position is located in the point far away from the wellbore face, when the perforation angle is around <TEX>$30^{\circ}$</TEX>; however, when the perforation angle is increased to <TEX>$45^{\circ}$</TEX>, a plane fracture is initiated from the wellbore face in the maximum horizontal stress direction; no fractures was found around perforation tunnels, when the angel is close to <TEX>$90^{\circ}$</TEX>. The results have been successfully applied in an oilfield, with the error of only 1.1% comparing the fracture initiation pressure simulated with the one from on-site experiment.

Perforasomes of the upper abdomen: An anatomical study

Pedicled perforator flaps in the trunk such as the DIEAP or the IMAP-flap have increasingly been used for reconstructive purposes. However, perforator flaps of the upper abdominal wall derived from the SEA and DIEA have not been widely reported in literature. The aim of this study was to investigate the vascular basis of perforator flaps of the upper abdominal wall based on the epigastric vascular axis and to describe the location and size of the individual flaps. The superior and deep inferior epigastric artery perforators (SEAPs and DIEAPs) of the supraumbilical abdominal wall of ten fresh anatomical specimens were selectively injected with Methylene blue solution or India ink. The location and size of the labeled skin area was observed. Finally, the arterial perforators were dissected and the length, diameter and the distance of the perforation point to the midline, xiphoid process and umbilicus were recorded. The SEAPs and DIEAPs supplied the ventromedial skin of the lower thoracic and supraumbilical abdominal wall in a sequential order. The mean size of all injected skin areas was 65 ± 31.4 cm(2) (10.2 × 8.8 cm). A mean number of 9.7 ± 4.2 perforators per specimen was identified. The mean external diameter of the dissected perforators was 0.82 ± 0.32 mm. The perforator length until arborization averaged 3.44 ± 1.07 cm. Most perforators were located in an area 2-6 cm from the midline and 0-10 cm below the xiphoid process. Through selective injection of perforators, a reliable anatomy of SEAP- and DIEAP-flaps of the upper abdominal wall could be demonstrated. From a clinical point of view, subcostal SEAP-flaps are of special interest. These flaps may be rotated cranially for lower chest wall or breast reconstruction or deflected caudally for abdominal wall reconstructive purposes. The harvest site can be closed directly or via a reverse abdominoplasty procedure.

Laparoscopic direct suture of perforation after diagnostic colonoscopy

Increasing colonoscopy use increases the incidence of iatrogenic colon perforation. Operative management of iatrogenic colonoscopic perforation is diverse. This study retrospectively reviewed our experiences in treating diagnostic colonoscopy-associated bowel perforation by laparoscopic direct suturing. A total of 89,014 patients underwent diagnostic colonoscopy at our institution during the past 6 years. We identified 17 iatrogenic perforations (0.019 %) that were all managed by laparoscopic direct suturing. Perforation patients included 11 men and 6 women (mean age 60 ± 18 years). Sixteen patients (94 %) had severe comorbidities or previous abdominal surgery. Perforations were noticed by the endoscopist during the procedure in 13 cases (76 %) while the remaining 4 cases (24 %) were diagnosed within 24 h after colonoscopy. The estimated mean longitudinal perforation length was 4.4 ± 2.1 cm. Mean operation time was 2.3 ± 0.6 h, without significant blood loss or other severe complication. The mean time to bowel function return was 3.4 ± 1.2 days, the mean time to initial oral intake was 3.9 ± 2.0 days and the mean hospitalization duration was 6.8 ± 4.2 days. Diagnostic colonoscopic perforation occurred in less than 2/10,000 patients when colonoscopy was performed by experienced operators in our endoscopy center. Most of the perforation patients had severe comorbidities, to which the surgeon should pay close attention during colonoscopy. Laparoscopic primary suture of colon perforations caused by diagnostic colonoscopy is a safe and feasible repair method. Further efforts will definitively assess the feasibility of routinely using laparoscopic direct suture to repair colon perforations.

The vascular basis of perforator flaps of the upper abdominal wall: an anatomical study

IntroductionPedicled perforator flaps in the trunk such as the DIEAP (deep inferior epigastric artery perforator) flap have increasingly been used for reconstructive purposes. However perforator flaps of the upper abdominal wall derived from the SEA (superior epigastric artery) and DIEA have not been widely reported. The aim of this study was to investigate the vascular basis of perforator flaps of the upper abdominal wall based on the epigastric vascular axis and to describe the location and size of the individual flaps.Material and MethodsThe superior and deep inferior epigastric artery perforators of the supraumbilical abdominal wall of ten fresh cadavers were injected with methylene blue solution or india ink. The location and size of the labelled skin area was observed. The arterial perforators were dissected and the length, diameter and the distance of the midline, xiphoid process and umbilicus to the perforation point was recorded.ResultsThe SEAPs and DIEAPs supplied the ventromedial skin of the lower thoracic and supraumbilical abdominal wall in a sequential order. The mean size of all injected skin areas was 65,8 ± 33,7 cm2 (9,9 × 8,8 cm). A mean number of 9,8 ± 4,2 perforators was identified. The mean external diameter of the dissected perforators was 0,8 ± 0,3 mm (range 0,5 – 1,9 mm). The perforator length until arborisation averaged 3,6 ± 1,1 cm (range 2 – 7 cm). Most Perforators were located in an area 4–6 cm from the midline and 5–10 cm below the xiphoid process.ConclusionsA reliable anatomy of SEAP and DIEAP flaps of the upper abdominal wall could be demonstrated. Especially subcostal SEAP flaps are of clinical interest. These flaps may be rotated cranially for lower chest wall reconstruction or deflected caudally for abdominal wall reconstructive purposes. The harvest site could be closed directly or via a reverse abdominoplasty procedure.Grant Funding Source: AAA