Dual Plane Research Articles

A damage model for the frictional shear failure of brittle materials in compression

Damage models have been successfully employed for many decades in the modelling of tensile failure, where the crack surfaces separate as a crack grows. The advantage of this approach is that crack trajectories can be computed simply and efficiently on a fixed finite element mesh without explicit tracking. The development of damage models for shear failure in compression, where the crack faces slide over each other subject to friction, is a non-trivial extension of this approach. A major difference is that part of the material stiffness in the damaged region must be retained to avoid interpenetration of the crack faces. This problem is resolved here by employing an anisotropic modification to the elastic stiffness tensor in the damaged region. This has the benefit of driving frictional cracks into the correct orientation, according to the Mohr–Coulomb failure criteria, but three issues remain. The first is that the shear discontinuity introduces some spurious stress perturbations around crack regions that are narrow (less than 3-4 elements wide). This is ameliorated by Helmholtz smoothing to allow efficient simulation on a coarse mesh. The second is that the complementarity of shear stress means that the shear stiffness is removed normal to the crack interface as well as parallel to it, and the third is that there are two potentially active failure planes at each point. Both these latter two issues are resolved by the introduction of a novel failure plane selection variable, which regulates either single plane or dual plane failure, and prevents the growth of erroneous cracks normal to the crack face. Both local and non-local models are investigated for linear and exponential strain softening responses. Unlike the non-local model, the local model demonstrates some mesh-size dependence, but it still retains some properties of interest, in that it supports narrower cracks and more rapidly forms a preference for the growth of a single crack when there are a number of competing cracks. The model is implemented in commercial finite element package COMSOL Multiphysics v5.5 and validated against two benchmark simulations: biaxial compression and the failure of a 45° slope. The correct crack angles, stipulated by the Mohr–Coulomb friction angle, are correctly reproduced, as is the post-failure residual frictional force in biaxial compression. The effect of the shear fracture energy on the force–displacement response is investigated, demonstrating successful simulation of the range of material behaviour expected in geological samples, from broad ranged gradual collapse to sharp, almost instantaneous failure.

Accuracy Of 6dof Kinematics Of Tibiofemoral Joint Using High-speed Dfis Combined With 3d Mri Model

Cui Zhang1,2,3,Yu Liu2* and Shaobai Wang21Biomechanics Laboratory, College of Sports and Health, Shandong Sport University, Jinan, China. 2School of Kinesiology, Shanghai University of Sport, Shanghai, China. 3Sports Biomehanics Laboratory, Shandong Institute of Sport Science, Jinan, China.*Yu Liu, (Corresponding author) PURPOSE: To validate the precision, accuracy and consistency of 6DOF movement of Tibiofemoral Joint via a custom high-speed Dual plane Fluoroscopic Imaging System(DFIS) combined with 3D MRI model registration. METHODS: 5 copper beads were embed in tibial and femur of one fresh pig hind leg separately. 3D beads rigid model and 3D skeleton model were reconstructed based on CT and MRI images of the beads and the tibia and femur of the pig hind leg separately. Flexion and extension movement of pig leg were recorded by high-speed DFIS. The registration results of 3D beads rigid model was set as gold standard. Bias, SD of bias, Bland-Altman analysis and Pearson correlation analysis were used to test the precision, accuracy and consistency of 6DOF results of MRI bone model, compare with gold standard. RESULTS: The 6DOF kinematic results of tibiofemoral joint obtained by high speed DFIS combined with MRI 3D bone model registration method was highly correlated to the results obtained by gold standard (r > 0.917). The bias and SD of bias of the anterior-posterior, medial-lateral, superior-inferior transitions, and flexion-extension, varus-valgus, internal-external rotations of tibiofemoral joint were in sub-millimeter and sub-degree level. The mean D-value of 3D MRI bone model registration and gold standard results were uniformly distributed within the consistency interval. CONCLUSION: Combined high-speed DFIS with MRI images to reconstruct 3D skeleton model for registration is a method with high accuracy, precision and consistency, which can be used to measure clinical 6DOF movement and soft tissue contact characteristics of the tibiofemoral joint. Funding was provided by the National Nature Science Foundation of China 81702211; the Movement Science Research Innovation Team(2019-183).

Coupled activity-current fluctuations in open quantum systems under strong symmetries

Strong symmetries in open quantum systems lead to broken ergodicity and the emergence of multiple degenerate steady states. From a quantum jump (trajectory) perspective, the appearance of multiple steady states is related to underlying dynamical phase transitions (DPTs) at the fluctuating level, leading to a dynamical coexistence of different transport channels classified by symmetry. In this paper we investigate how strong symmetries affect both the transport properties and the activity patterns of a particular class of Markovian open quantum system, a three-qubit model under the action of a magnetic field and in contact with a thermal bath. We find a pair of twin DPTs in exciton current statistics, induced by the strong symmetry and related by time reversibility, where a zero-current exchange-antisymmetric phase coexists with a symmetric phase of negative exciton current. On the other hand, the activity statistics exhibits a single DPT where the symmetric and antisymmetric phases of different but nonzero activities dynamically coexists. Interestingly, the maximum current and maximum activity phases do not coincide for this three-qubits system. We also investigate how symmetries are reflected in the joint large deviation statistics of the activity and the current, a central issue in the characterization of the complex quantum jump dynamics. The presence of a strong symmetry under nonequilibrium conditions implies non-analyticities in the dynamical free energy in the dual activity-current plane (or equivalently in the joint activity-current large deviation function), including an activity-driven current lockdown phase for activities below some critical threshold. Remarkably, the DPT predicted around the steady state and its Gallavotti–Cohen twin dual are extended into lines of first-order DPTs in the current-activity plane, with a nontrivial structure which depends on the transport and activity properties of each of the symmetry phases. Finally, we also study the effect of a symmetry-breaking, ergodicity-restoring dephasing channel on the coupled activity-current statistics for this model. Interestingly, we observe that while this dephasing noise destroys the symmetry-induced DPTs, the underlying topological symmetry leaves a dynamical fingerprint in the form of an intermittent, bursty on/off dynamics between the different symmetry sectors.

Simplified measurement of the strain to fracture for plane strain tension: On the use of 2D DIC for dual hole plane strain tension mini Nakazima specimens with dihedral punch

A plane-strain-tension stress state leads to a minimum in ductility in most micro-mechanical and phenomenological fracture models as well as Forming Limit Curves. Hence, this stress state plays a crucial role in many applications and a reliable measurement of the strain to fracture under plane strain tension is of particular importance when calibrating modern fracture initiation models. Recently, a new experimental technique has been proposed for measuring the strain to fracture for sheet metal after proportional loading under plane strain conditions. The basic configuration of the novel setup includes a dihedral punch applying out-of-plane loading onto a Nakazima-type disc-shaped specimen with two symmetric circular cut-outs. 3D Digital Image Correlation (DIC) is used to measure the surface strains of the specimen up to fracture. In contrast to the widely used V-Bending test, the maximum obtainable strain is not limited when using this set up, and fracture will always initiate after proportional loading in a plane strain tension stress state. In the present study, a major simplification of the testing methodology is proposed, reducing from 3D DIC to a simple 2D DIC method for measuring the fracture strain. Comparisons are presented on three metals, a 1.5 mm thick DP600 steel, a 0.8 mm thick DP450 steel and a 1.2 mm thick AA2024 aluminum alloy.

Comparative study of patient outcomes between direct to implant and two-stage implant-based breast reconstruction after mastectomy

Breast reconstruction plays a central role in the outcome management of patients with breast cancer, particularly in terms of quality of life (QoL), which must be weighed carefully when considering the available surgical options. In the context of implant-based breast reconstruction, immediate replacement with prosthesis (direct-to-implant (DTI)) and acellular dermal matrix (ADM) is gaining popularity, at the expense of the traditional two-stage implant-based breast reconstruction with tissue expander (TE), and the literature suggests that patients tend to prefer interventions with "immediate" therapeutic efficacy and aesthetic satisfaction that obviate the need for further invasive surgery. We investigated this hypothesis by administering the BREAST-Q™ questionnaire to two groups of patients who had undergone the respective procedures. We performed a cross-sectional observational study of 192 consecutive mastectomy patients who received implant-based reconstruction, comparing health-related quality of life (HR-QoL), patient-related outcomes (PROs) and satisfaction in patients who had undergone immediate dual plane DTI with ADM (96) versus the two-stage submuscular approach (96). We also counted the number of surgeries required in each group to achieve a definitive outcome. Our study revealed no major differences in terms of QoL scores, with the two approaches being largely comparable. However, single-stage reconstruction seems to offer the additional advantages of better satisfaction with the care received, sparing the patient temporary body image dissatisfaction and reducing the number of surgeries required, thereby lessening the burden on the patient, the healthcare system and society as a whole.

Does Overfilling Smooth Inflatable Saline-Filled Breast Implants Decrease the Deflation Rate? Experience with 4761 Augmentation Mammaplasty Patients

BackgroundResearch suggests that overfilling saline inflatable breast implants may decrease their deflation rates. To date, there has been no large-scale study comparing breast implants filled within vs. beyond the manufacturer’s recommended fill volumes.MethodsA retrospective comparative study was conducted for 4761 women who underwent aesthetic augmentation mammaplasty by the author. Patients were divided into two groups: Group 1 includes 2960 patients who had breast augmentation between 2002 and 2009 with implants filled within the manufacturer’s recommended fill volumes. Group 2 includes 1801 patients who had breast augmentation between 2011 and 2018. Their implants were overfilled with an average volume between 42 and 50 cc, or 10–13%, respectively.All surgeries were performed with Mentor Style 1600 saline breast implants (smooth, round moderate profile) through an inframammary incision; implants were placed in the subpectoral (dual) plane. Also evaluated was the yearly increase in deflation rates.ResultsGroup I had 119 deflations, representing a deflation rate of 4.02%. Group 2 had 33 deflations, providing a deflation rate of 1.83%. The author found a protective effect in overfilling the device (p < 0.00001 and Z-score of 4.17). Fold failure was the major reason for deflation in both groups.The implants filled within the manufacturer’s recommended volume had a yearly increase in deflation rate of 0.41%, not 1% as is commonly reported. The overfilled implants did not have a yearly increase in deflation rate.ConclusionOverfilling Mentor Style 1600 saline breast implants (smooth, round moderate profile) 10–13% significantly reduced the deflation rate.Level of Evidence IIIThis journal requires that authors assign a level of evidence to each article. 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.

Immediate prepectoral implant reconstruction using TiLOOP Bra Pocket results in improved patient satisfaction over dual plane reconstruction

Implant-based reconstruction accounts for the majority of breast reconstructive procedures performed in Australia. More recently, immediate prepectoral implant reconstruction using the TiLOOP Bra Pocket has gained popularity. This study compares post-surgical complications and patient-reported quality of life outcomes between immediate prepectoral and dual plane implant reconstruction. A retrospective study of 80 consecutive patients who underwent nipple-sparing mastectomies and immediate implant reconstruction was conducted. Implants were either completely covered with TiLOOP Bra and/or TiLOOP Bra Pocket (pfm medical, Cologne, Germany) and secured in the prepectoral space (prepectoral group) or placed in the subpectoral plane with inferolateral mesh coverage (dual plane group). Data surrounding patient demographics, clinical details and post-surgical outcomes were compared. Patient-related quality of life outcomes were assessed with the Breast-Q questionnaire. A total of 80 patients (109 breasts) operated on between June 2016 and December 2018 were included. The prepectoral and dual plane groups comprised of 40 patients each, including 50 and 59 operated breasts, respectively. Post-operative complications were comparable with 11 (22%) overall complications in the prepectoral group and eight (14%) in the dual plane group (P = 0.313). Implant loss was uncommon with four (8%) cases in the prepectoral group and five (8.5%) in the dual plane group (P = 0.929). Patient-reported quality of life outcomes were superior after prepectoral reconstruction with patients reporting a significantly higher score in the satisfaction with breasts domain (68.9 versus 57.5; P = 0.036). Immediate prepectoral implant reconstruction with the TiLOOP Bra Pocket was associated with improved patient satisfaction and demonstrated no difference in early post-operative outcomes.

Limits of dual curves via foliations

We develop a method to compute limits of dual plane curves in Zeuthen families of any kind. More precisely, we compute the limit 0-cycle of the ramification scheme of a general linear system on the generic fiber, only assumed geometrically reduced, of a Zeuthen family of any kind.

In search for the ‘perfect’ breast implant: are textured implants still indicated in today’s breast augmentation practice?

The popularity of breast augmentation procedure has driven research and debate as to whether any given implant characteristic offers a functional advantage. One such debate exists about the role of surface texturing. In the aftermath of the recent withdrawal of aggressively textured surfaces we would like to summarize the first author’s experience of nearly 1500 primary aesthetic breast augmentations with different surfaces and offer our thoughts on this topic. All consecutive primary breast augmentations operated by the first author from January 2010 to June 2019 were included. All patients had silicone implants inserted via inframammary incision. Of all the operated cases, 1029 consecutive female patients had at least 6 months’ follow-up (mean 15.1 months). Their mean age was 31.2 years, mean BMI 20.8 kg/m2 and mean implant volume was 311 cc. 997(96.9%) patients had dual plane and 32(3.1%) had sub-glandular implant placement. In total 113 patients (11.0%) developed a complication. This represented 15.1% of those with round and 10.0% of anatomical shape (or 10.6% of textured and 14.5% of smooth surface implants). As clinicians, we like patients to receive all the advantages of an implant but not be exposed to any risks. However, in reality, such a ‘perfect implant’ still does not exist. New literature continues to shed light on this trade-off between an implant’s perceived utility and its complications profile. We hope that the search for an alternative technology, with more beneficial surface characteristics and less drawbacks, continues.

大视场间隔双焦面成像遥感相机焦面装调

大视场间隔双焦面成像遥感相机焦面装调

大视场间隔双焦面成像遥感相机焦面装调

大视场间隔双焦面成像遥感相机焦面装调

Comparison of subpectoral versus dual-plane implant based immediate breast reconstruction after nipple-areola sparing mastectomy

Selection of implant pocket and size is a dilemma for surgeons especially if radiation therapy is envisaged after implant based immediate breast reconstruction (IBR). The aim of this study is to compare complication rates between subpectoral and the dual plane polyglactin mesh supported IBR after nipple-areola sparing mastectomy. Reconstructive analysis of 208 breasts of 190 patients with breast cancer undergoing implant based IBR at a single university hospital were evaluated. The patients were reconstructed with either dual-plane polyglactin mesh supported (n=91) or subpectoral (n=117) implant based IBR after nipple-areola sparing mastectomy. Demographic data, and postoperative complications were compared. The mean age was 43.3 years. Early complications encountered in 12% (n=25) and late complications occurred in 18% (n=37) of breasts. Both early (13,7% vs 9.9%, P=0.406) and late complications (24.8% vs 8.8%, P=0.003) were more common in subpectoral group, but only late complication occurrence rate was statistically significant. Capsular contracture (P=0.000), inframammary fold problems (P=0.010), bottoming-out (P=0.370), mechanical shift (P=0.036) and animation deformity (P=0.007) were all more common in subpectoral group. Only rippling deformity (P=0.011) was more common in dual plane group. Dual plane IBR has acceptable complication rates compared to subpectoral IBR. It is associated with less capsular contracture, fewer animation and bottoming-out deformity and better inframammary fold appearance.

Flow and mixing characteristics of dual parallel plane jets subject to acoustic excitation

The effects of jet pulsation intensity and excitation Strouhal number on the flow and dispersion characteristics of dual parallel plane jets at a low Reynolds number of 200 were experimentally studied so that the transition from laminar to turbulence was focused. A hot-wire anemometer was used to record the jet velocities. The flow patterns were obtained using the laser-light sheet assisted smoke flow visualization technique. Jet spread widths were derived from the long-exposure images using the binary edge detection method. The jet fluid dispersion characteristics were examined using the tracer-gas concentration detection technique. Four characteristic flow modes (discrete coherent vortices, contiguous coherent vortices, early vortex breakup, and lateral dispersion) were identified in the domain of the jet pulsation intensity and excitation Strouhal number. At small jet pulsation intensities, discrete and contiguous coherent vortices appeared at low and high excitation Strouhal numbers, respectively. The vortices appearing in the jet shear layers broke up slowly and caused small jet expansions and turbulent intensities, thus inducing a low efficiency of jet fluid dispersion. The early vortex breakup mode was induced by the low-frequency back-and-forth flow motions in the near region at large jet pulsation intensities and low excitation Strouhal numbers. Large turbulence fluctuations caused by the early vortex breakup increased the jet dispersion significantly. At large jet pulsation intensities and excitation Strouhal numbers, high-frequency back-and-forth flow motions in the region near the jet exits significantly reduced the time-averaged axial momentum and induced large lateral jet expansion and jet fluid dispersions.

Effects of pulsation intensity on the flow and dispersion of pulsed dual plane jets

The effects of jet pulsation intensity on the flow and dispersion characteristics of dual parallel plane jets were experimentally studied. The jet pulsations were generated by acoustic excitations. The laser-light-sheet-assisted smoke flow visualization method was used to study the flow evolution processes. The lateral spreading characteristics of the jets were measured using the binary edge detection method. A hotwire anemometer was used to measure the velocity pulsations, mean velocities, turbulence intensities, and Lagrangian turbulent length and time scales. The dispersion characteristics of the jet fluids were measured by the tracer-gas concentration detection method. The jet Reynolds number and excitation Strouhal number were fixed at 600 and 0.106, respectively. The jet pulsation intensities were varied from 0 to 1.6. As the jets were pulsed, the turbulence intensity, lateral spread width, and jet fluid dispersion capability markedly increased compared with those of the non-pulsed jets. The larger the pulsation intensity was, the higher the turbulence intensity, lateral spread width, and jet fluid dispersion. The Lagrangian time and length scales of the turbulent eddies decreased as the jet pulsation intensity increased because the mushroom-shaped structures generated by the jet pulsations broke up into small turbulent eddies caused by the strong vortex-stretching effect.

Multimodal Two-Phase Flow Measurement Using Dual Plane ECT and GRT

This work assesses the accuracy of two-phase flow measurement, based on cross correlation (XC) and cross-spectrum (CS) velocity computation, using dual plane nonintrusive electrical capacitance tomography (ECT), over a broad spectrum of horizontal flow configurations, combined with fraction distribution measurements from gamma-ray tomography (GRT). The measurement of two-phase flow encompasses the measurement of both the velocity and the phase concentration of the flow components. The accuracy of the flow velocity is still an open discussion and remains a key challenge in the field of multiphase flow measurement. The velocities of the two-phase components vary, both in between them and across the pipe cross section. This study assesses the use of XC techniques as methods for calculating the cross-sectional velocity distribution by deriving the transit time of the fluid flowing through two parallel ECT sensor arrays mounted on the perimeter of a pipe. The spectral distribution of the velocities is assessed for improved accuracy of individual component velocities. A dual-plane ECT is adopted for the velocity measurements and is combined with state-of-the-art density-based cross-sectional phase fraction distribution from a GRT system to measure the volumetric flow rates of the two phases. The results show that the CS method provides enhanced velocity estimation for both flow phases over the conventional XC technique. Further improvement was reported using a simple predictive correction model resulting in flowrate estimation accuracy of ±10%. The method for two-phase flow measurement suggested in this work leverages the accuracy of the tomography systems on accurate fraction measurement and fast data acquisition to lead to potential enhancement in process control by enabling a more accurate prediction of components velocities.

125 Poster - Quality of life improvement and pain reduction in implant-based breast reconstruction by means of selective pectoralis major muscle denervation

Background: Implant-based breast reconstruction (IBBR) is the preferred choice of breast reconstruction after mastectomy worldwide. Even in the era of pre-pectoral reconstructions, the retro-pectoral approach is still largely used for its reliability and surgical safety, especially in case of previous radiation therapy, in smokers, in diabetics or in case of skinny mastectomy flaps. However it often leads to unsatisfactory aesthetic and functional results. To avoid such limits and reduce post-mastectomy pain syndrome (PMPS) to the minimum, in 2016 we introduced a novel technical approach, namely, pectoralis major muscle selective denervation, either in tissue expander or DTI retro-pectoral dual plane procedures.

Funnel usefulness in direct-to-implant breast reconstruction using periareolar incision with prepectoral implant placement and complete coverage with acellular dermal matrix

The funnel has been used in esthetic breast surgery that requires a small incision. Recent advances in minimally invasive surgical techniques have led to more cases of nipple-sparing mastectomy (NSM) through periareolar incision. However, prepectoral implant placement and complete coverage with acellular dermal matrix (ADM) is almost impossible with the periareolar approach. Funnels can also be useful for direct-to-implant breast reconstruction. NSM with periareolar incision and direct-to-implant breast reconstruction were performed with prepectoral implant placement between January 2017 and July 2019. The ADM full-wrapped anatomic textured implant was inserted using a funnel without additional incisions during surgery. A total of 21 patients were enrolled, including 2 who received bilateral breast reconstruction. All operations were successfully performed using funnels with minimal periareolar incisions. Anatomic textured implants (mean: 251.7 cc, range: 90-450 cc) wrapped in ADM can be effectively inserted in the prepectoral plane using a funnel. Two patients experienced delayed wound healing of the areola that was treated by conservative wound management. Patients also experienced less pain overall, and the cosmetic result was very good. Patient satisfaction scores were also very high. While the periareolar incision is esthetically pleasing, additional resection is often necessary. However, the use of funnels ensured that no additional incision was needed even in large implants. This subsequently led to better results in terms of pain and scarring. Prepectoral breast reconstruction involving complete implant coverage with ADM using a funnel through the periareolar approach represents a good alternative to the traditional dual plane subpectoral method. This method provides good patient satisfaction without adverse outcomes.

Evaluation of satisfaction and well being with Breast-Q© of aesthetic breast augmentations by implants using the “Dual Plane” technique: A serie of 191 cases

Dual Plane allows, according to J.B Tebbetts, to combine the advantages while reducing the drawbacks of the other implantation pockets. We assessed patient satisfaction using the Breast-Q © questionnaire after breast augmentation using the Dual Plane technique. Our study involved evaluating data from the Breast-Q © questionnaire from 191 patients retrospectively. Other secondary criteria were studied such as postoperative complications, the correlation between satisfaction and implant volume, satisfaction and operating time, satisfaction and age of the patient. The Breast-Q © questionnaire allows us to assess the satisfaction of the patients in our series about their breasts, their implants, the information received and the outcome of the intervention. Physical, sexual and psychosocial well-being is also assessed. Breast augmentation using a Dual Plane pocket according to Tebbetts achieves significant levels of satisfaction and well-being in patients. To our knowledge, this is the most important series devoted to the evaluation of these criteria after the use of the Dual Plane.

Sum–product phenomena for planar hypercomplex numbers

We study the sum–product problem for the planar hypercomplex numbers: the dual numbers and double numbers. These number systems are similar to the complex numbers, but it turns out that they have a very different combinatorial behavior. We identify parameters that control the behavior of these problems, and derive sum–product bounds that depend on these parameters. For the dual numbers we expose a range where the minimum value of max{|A+A|,|AA|} is neither close to |A| nor to |A|2.To obtain our main sum–product bound, we extend Elekes’ sum–product technique that relies on point–line incidences. Our extension is significantly more involved than the original proof, and in some sense runs the original technique a few times in a bootstrapping manner. We also study point–line incidences in the dual plane and in the double plane, developing analogs of the Szemerédi–Trotter theorem. As in the case of the sum–product problem, it turns out that the dual and double variants behave differently than the complex and real ones.

Comparing post-operative analgesic effects of varying doses of dexmedetomidine as an adjuvant to ropivacaine for ultrasound-guided dual transversus abdominis plane block following laparotomy for gynecologic malignancies.

The aim of the present study was to determine the analgesic effects of ropivacaine combined with different doses of dexmedetomidine for ultrasound-guided transversus abdominis plane (TAP) block immediately following laparotomy in patients with gynecologic malignancies. A further aim was to determine the appropriate clinical dose of dexmedetomidine as an adjuvant for ropivacaine. Patients with gynecologic malignancies scheduled for laparotomy were randomly assigned to group R (TAP block with 0.3% ropivacaine), group RD1 (TAP block with ropivacaine and 0.5 µg/kg dexmedetomidine), group RD2 (TAP block with ropivacaine and 1 µg/kg dexmedetomidine) and group RD3 (TAP block with ropivacaine and 2 µg/kg dexmedetomidine). TAP blocks were performed post-operatively. The four groups all received patient-controlled intravenous analgesia (PCIA) after the operation. The numerical rating scale (NRS) as well as the Ramsay sedation scale (RSS) scores, the first request time for PCIA bolus, oxycodone hydrochloride consumption, the plasma concentration of ropivacaine, the incidence of post-operative complications and adverse events, and patient satisfaction were recorded. Post-operative NRS scores at rest exhibited significant differences between the R group and all the RD groups at 24 h after surgery (P<0.05). Compared with the other groups, the NRS score in the RD3 group was decreased (P<0.05). The RSS scores were higher in all of the RD groups compared with those in the R group at 2 h (P<0.05) and were highest in the RD3 group compared with those in all other groups at 4 h (P<0.05). The first request time for PCIA was significantly longer in the RD3 group compared with that in the RD2, RD1 and R groups (510.47±102.67, 595.47±100.11, 682.43±104.46 and 776.42±143.91 min, respectively; P<0.05). Cumulative opioid consumption based on the number of PCIA bolus requested at 24 and 48 h post-operatively indicated that the total number of PCIA boluses was significantly lower in the RD groups compared with those in the R group at 24 and 48 h (P<0.05). The ropivacaine concentration did not differ among the four groups. There was no significant difference between groups with respect to post-operative nausea and vomiting, bradycardia and hypotension; however, all RD groups had a higher patient satisfaction than group R (P<0.05). Compared with that in the other groups, the duration of post-anesthesia care unit stay in group RD3 was relatively longer due to excessive sedation (P<0.05). In conclusion, TAP blockade using 0.5-2 µg/kg dexmedetomidine combined with 0.3% ropivacaine is a safe and effective treatment for analgesia in laparotomy procedures for gynecologic malignancies. The study was registered in the Chinese Clinical Trial Registry (CHICTR; www.chictr.org.cn) on January 15th, 2019 (registration no. ChiCTR1900020995).