Introduction
Ultrasound (US)-guided fascial plane blocks represent a modern regional anesthesia technique that targets fascial planes, without the need for nerve visualization.1 The quadratus lumborum block (QLB) is a fascial block aimed at providing perioperative analgesia for the abdomen. It works by anesthetizing the ventral branches of the thoracolumbar nerves and the sympathetic truck.1 These nerves are responsible for the visceral and a portion of the somatic innervation of the abdomen. Prior methods, such as neuraxial anesthesia and transversus abdominal plane (TAP) blocks, have been employed to manage abdominal nociception.2 Epidural anesthesia may provide excellent abdominal analgesia but carries risks of several complications,3 while a bilateral TAP block leads to somatic analgesia of the abdominal wall without providing satisfactory visceral analgesia.2 Hence, the TAP block can only be used as a part of a multimodal analgesia strategy for abdominal surgery.4 On the other hand, the US-guided QLB is a relatively safe and easy technique to perform, with minimal risk of nerve injury,5 making it a valid alternative for controlling abdominal pain.
The quadratus lumborum block has been demonstrated to provide analgesia of both the abdominal wall and viscera in humans.1 In animals, multiple cadaveric studies have been conducted of dogs6–9 and cats.6,7,10 Nevertheless, there is limited clinical evidence in veterinary medicine, with only 1 clinical study8 showing the analgesic effectiveness of this block in cats undergoing ovariectomy. Five approaches have been described in veterinary medicine: lateral,9 lateroventral,11 dorsal,7,12,13 modified dorsal,14 and intermuscular.8,15–17 The present study aimed to assess the effectiveness of the US-guided QLB, utilizing the lateral approach, in providing visceral and somatic analgesia of the abdomen in cats undergoing ovariectomy. We hypothesized that administering QLB with 2 different volumes (0.3 and 0.5 mL/kg) of 0.2% bupivacaine, compared to a control group, would result in antinociception and reduce the need for intraoperative rescue analgesia in healthy cats undergoing ovariectomy. Furthermore, we hypothesized that the higher volume (HV) of bupivacaine would result in better perioperative analgesia compared to the lower volume (LV).
Methods
The study protocol was approved by the Association of Veterinary Anaesthetists Ethical Committee (protocol No. 2022-002), and, for each cat, written informed consent was acquired from the owner.
Animals
Sample size was calculated with G* Power Software (Heinrich-Heine-Universität Düsseldorf) with an F test a priori analysis on the basis of data recorded in a pilot study. A total sample size of at least 48 cats was calculated to achieve 80% statistical power with a type I error of 5 and an effect size of 0.53 to detect a difference in fentanyl consumption between the groups.
A total of 48 female client-owned cats of any age and breed scheduled for elective ovariectomy were enrolled in the study. Inclusion criteria included cats with an American Society of Anesthesiologists physical status of I or II, determined through physical examination, CBC, blood biochemistry profile, and a cardiac evaluation. Cats presenting with cardiac, renal, or hepatic disease; pregnancy; obesity (body condition score of 8/9 or 9/9); extreme aggression; or blood test or electrocardiogram abnormalities were excluded. Cats receiving any analgesic within 7 days before surgery and those with any contraindication to the use of peripheral nerve block administration (coagulopathies, skin infections, anatomical abnormalities, and history of adverse reactions to local anesthetics) were also excluded.
Study design
A prospective randomized blinded clinical trial was designed and completed within a 6-month period. Food, but not water, was withheld from 8 hours prior to anesthesia. After acclimatization to a quiet environment, all cats were premedicated with dexmedetomidine (5 µg/kg), ketamine (1 mg/kg), and methadone (0.2 mg/kg) mixed in a 1-mL single syringe (InJ/Light; Ray Med) in the quadriceps femoris muscle. An appropriately sized (22-gauge) IV catheter (Delta ven 1; Delta Med) was placed aseptically in the cephalic vein. Endotracheal intubation was performed after induction with IV propofol (Proposure) administered to effect and topical administration of 0.2 mL lidocaine 2% (Lidocaina 2%). Anesthesia was maintained with isoflurane (Isoflo) in a mixture of medical air and oxygen at 200 mL/kg/min (FiO2: 40%) via a circle breathing system (Draeger Cato; Dragerwerk AG & Co) with the patient breathing spontaneously. With an online randomizer (Random.org), cats were allocated into 3 groups as shown in Figure 1.
Consolidated Standards for the Reporting of Trials flow diagram. Cats were randomly divided into 3 groups to receive ultrasound (US)-guided bilateral quadratus lumborum block (QLB) with low-volume (LV) bupivacaine 0.2% at 0.3 mL/kg/side (QLB-LV group), high-volume (HV) bupivacaine 0.2% at 0.5 mL/kg/side (QLB-HV group), or no QLB (control group; C).
Citation: Journal of the American Veterinary Medical Association 262, 11; 10.2460/javma.24.03.0202
Quadratus lumborum block execution
The US-guided QLB was performed by an experienced anesthetist skilled in US-guided regional anesthesia who did not participate in the intra- and postoperative phases. A high-frequency linear 13-6 MHz ultrasound probe (Vinno 6 Vet; Vinno) and the lateral approach described by Garbin et al9 were used. The cat was positioned in lateral recumbency, and the hair was bilaterally clipped from the last rib to the iliac crest and from the dorsal aspect of the transverse process of the lumbar vertebrae to the abdominal midline. Surgical antisepsis was applied, and an alcohol-based solution was used for acoustic coupling. After confirming negative blood aspiration, cats in the QLB-LV group received 0.3 mL of bupivacaine 0.2%/kg/side (totaling 1.2 mg/kg; Bupisen 0.5%) and cats in the QLB-HV group received 0.5 mL of bupivacaine 0.2%/kg/side (totaling 2 mg/kg). The dilution of the bupivacaine was performed with saline solution (NaCl 0.9%; B Braun Vet Care). A second anesthetist masked to the treatment group oversaw the patient for the intra- and postoperative evaluations. Any eventual signs of local anesthetic toxicity or nerve block complications were documented. Surgery was started 15 minutes after the QLB.
Intraoperative monitoring
Intraoperative monitoring (S5 Compact Anesthesia Monitor; Datex Ohmeda) included the following: heart rate (HR; beats/min), respiratory rate (ƒR; breaths/min), arterial hemoglobin oxygen saturation (SpO2; percentage), end-tidal carbon dioxide tension (PETCO2; mm Hg), end-tidal isoflurane concentration (PETISO; percentage), and esophageal temperature. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure was measured with an oscillometer technique (Vet20 SunTech; SunTech Medical Inc) with the cuff (40% of limb circumference) positioned on the right or left antebrachium. An operator recorded all of the physiological parameters before skin incision (T0, baseline), then in 5-minute intervals (T5, T10, T15). Additionally, at the time of both ovarian manipulations, HR was specifically noted and recorded. The anesthetists in charge of intraoperative monitoring were masked to the treatment group allocation.
The PETISO was initially set to 1.3% to 1.2% and gradually decreased by 0.1% every 5 minutes during the surgery, ensuring an adequate anesthetic level. If a further reduction in the PETISO was perceived by the anesthetist as leading to an inadequate depth of anesthesia, the PETISO reduction was stopped. The goal was to achieve the lowest PETISO possible while still maintaining a stable surgical anesthesia plane, indicated by the absence of palpebral reflex and jaw muscle tone and presence of downward eye rotation. For cases in which the depth of anesthesia was deemed inadequate, isoflurane was increased by 0.2%. If this adjustment proved ineffective, 0.5 mg of propofol/kg was administered.
Intravenous fluid therapy was provided with 3 mL of lactated Ringer solution/kg/h (Ringer Lattato). A dose of 25 mg of cefazolin/kg (Cefazolina) was administered IV 20 minutes before surgery. In the case of hypotension (MAP below 60 mm Hg), a bolus infusion of lactated Ringer solution was administered at a rate of 5 mL/kg over 10 minutes. If hypotension persisted, a constant rate infusion of noradrenaline (Noradrenalina Tartrato Galenica Senese; 2 mg/mL) was started at 0.5 µg/kg/min and then gradually reduced by 0.1 µg/kg/min every 5 minutes while maintaining normotension.
Surgery was performed via ventral midline approach by the same experienced surgeon. At the end of the surgery, isoflurane was discontinued, and cats were extubated when the swallowing reflex returned. The durations of anesthesia (from induction to discontinuation of isoflurane) and surgery (from abdominal midline incision time until placement of the last suture) were recorded. After extubation, 0.1 mg of meloxicam/kg (Metacam 5 mg/kg) was administered subcutaneously to all cats. Heating support (Bair Hugger Animal Health Blankets; 3M) was continued until rectal temperature was above 37.5 °C.
Intra- and postoperative pain assessment and rescue analgesia
Intraoperative nociception was assessed on the basis of cardiovascular and respiratory responses to surgical stimulation. An increase of > 20% from baseline in HR, ƒR, and SAP related to any surgical stimulus was considered nociception, and rescue analgesia (1 µg of fentanyl/kg, IV; Fentadon) was administered. The administration of fentanyl was registered (yes/no), and the total amount (µg/kg) of intraoperative boluses given to each patient was recorded.
Postoperative pain was assessed at 4 hours after extubation. Cats were initially observed inside their cage. Then, they were approached and spoken to, and the cage door was opened. Each cat was gently handled, petted, and encouraged to walk, and finally the incision site and surrounding skin was gently palpated. Feline Grimace Scale scoring from 0 (no pain) to 10 (severe pain) was used by a trained investigator unaware of the treatment allocation. Rescue postoperative analgesia (buprenorphine, 0.2 mg/kg, IM; Buprephelican) was administered to cats that had a Feline Grimace Scale score ≥ 4 after a 4-hour evaluation period. The general study design is outlined in Figure 2.
Study timeline. All cats were premedicated (PREMED) with IM dexmedetomidine (5 µg/kg), ketamine (1 mg/kg), and methadone (0.2 mg/kg). Approximately 20 minutes later, anesthesia was induced with 2 to 4 mg of propofol/kg and general anesthesia was maintained with isoflurane. Cats were randomly divided into 3 groups: QLB-LV, QLB-HV, or C. All cats underwent ovariectomy, and intra- and postoperative pain levels were evaluated. Additionally, heart rate (HR), respiratory rate (ƒR,) arterial hemoglobin oxygen saturation (SpO2), end-tidal carbon dioxide tension (PETCO2), end-tidal isoflurane concentration (PETISO), esophageal temperature (T°), and systolic, mean, and diastolic arterial blood pressure (SAP, MAP, and DAP, respectively) were measured. Data were collected before skin incision (baseline) then in 5-minute intervals (T5, T10, T15). At the end of the surgery, 0.2 mg of meloxicam/kg was administered. Postoperative pain was assessed at 4 hours after extubation.
Citation: Journal of the American Veterinary Medical Association 262, 11; 10.2460/javma.24.03.0202
Statistical analysis
The data analysis was performed with JASP software (version 0.17.1; The JASP Team). Data normality was assessed with the Shapiro-Wilk test. Continuous data were reported as mean ± SD for parametric variables or median ± range for nonparametric variables. Categorical variables were presented as proportions. Normally distributed data were compared with 1-way ANOVA with a Dunn multiple comparisons post hoc test followed by Bonferroni correction. For nonnormally distributed data, the Kruskal-Wallis test was used for group comparisons with a Dunn multiple comparisons post hoc test followed by Bonferroni correction. The requirement for rescue analgesia was compared with a χ2 test, and pairwise comparisons were carried out with a Fisher exact probability test. In all analyses, P < .05 was considered statistically significant.
Results
A total of 48 cats were enrolled in the study, and the 3 groups were homogeneous in terms of age and weight. The cats’ mean age was 9 ± 2 months in the QLB-LV group, 8 ± 2 months in the QLB-HV group, and 11 ± 7 months in the control group. Their respective median weights were 3 kg (2.4 to 4.2 kg) in the QLB-LV group, 3.1 kg (2.3 to 3.5 kg) in the QLB-HV group, and 3.5 kg (2.4 to 4.5 kg) in the control group. Analysis of the duration of anesthesia and surgery revealed no statistically significant differences between groups: QLB-LV, 50.8 ± 3.4 minutes and 18.8 ± 3 minutes, respectively; QLB-HV, 50.3 ± 4.0 minutes and 18.3 ± 3.8 minutes, respectively; and control, 51.5 ± 4 minutes and 19 ± 4.3 minutes, respectively.
No significant differences were found between the groups in HR, SAP, MAP, DAP, ƒR, PETISO, or esophageal temperature when data reported every 5 minutes were analyzed (Table 1).
Intraoperative mean ± SD values of heart rate (HR) and median (range) values of respiratory rate (ƒR), end tidal isoflurane concentration (PETISO), and systolic (SAP), mean (MAP), and diastolic arterial pressure (DAP) of 48 cats undergoing ovariectomy.
| Parameter | Group | Intraoperative time point | |||
|---|---|---|---|---|---|
| Baseline | T5 | T10 | T15 | ||
| HR (beats/min) | QLB-LV | 105 ± 15 | 100 ± 19 | 106 ± 17 | 105 ± 15 |
| QLB-HV | 115 ± 10 | 106 ± 11 | 104 ± 13 | 106 ± 14 | |
| C | 115 ± 14 | 114 ± 16 | 118 ± 18 | 111 ± 14 | |
| ƒR (breaths/min) | QLB-LV | 20 (14–26) | 17 (10–26) | 16 (10–25) | 16 (12–24) |
| QLB-HV | 20 (12–31) | 18 (12–24) | 18 (12–24) | 18 (12–22) | |
| C | 20 (12–29) | 18 (12–30) | 17 (12–40) | 17 (10–40) | |
| PETISO (%) | QLB-LV | 1.2 (1.2–1.4) | 1.1 (1.1–1.2) | 1 (0.8–1.1) | 0.9 (0.7–1) |
| QLB-HV | 1.2 (1.1–1.4) | 1.1 (1–1.3) | 1 (0.9–1.2) | 0.9 (0.8–1.1) | |
| C | 1.2 (1.2–1.4) | 1.2 (1.1–1.3) | 1.1 (0.9–1.2) | 1 (0.9–1.1) | |
| SAP (mm Hg) | QLB-LV | 119 (96–165) | 105 (90–160) | 110 (81–162) | 102 (86–152) |
| QLB-HV | 112 (76–177) | 104 (78–177) | 104 (80–160) | 104 (86–160) | |
| C | 115 (72–190) | 98 (86–160) | 101 (80–260) | 100 (80–167) | |
| MAP (mm Hg) | QLB-LV | 85 (67–118) | 71 (59–112) | 76 (62–119) | 75 (61–115) |
| QLB-HV | 87 (60–164) | 77 (60–160) | 78 (62–166) | 70 (61–161) | |
| C | 91 (61–148) | 75 (61–142) | 80 (59–196) | 69 (55–133) | |
| DAP (mm Hg) | QLB-LV | 67 (37–105) | 60 (42–94) | 64 (30–100) | 59 (46–94) |
| QLB-HV | 77 (44–115) | 59 (37–115) | 62 (42–118) | 59 (44–119) | |
| C | 77 (49–133) | 66 (45–120) | 64 (39–160) | 58 (40–122) | |
Baseline = Before skin incision. C = Control group (no block, n = 16). QLB-HV = Quadratus lumborum block, high volume (0.5 mL/kg/side, bupivacaine 0.2%) group (n = 16). QLB-LV = Quadratus lumborum block, low volume (0.3 mL/kg/side, bupivacaine 0.2%) group (n = 16). T10 = Ten minutes after baseline. T15 = Fifteen minutes after baseline. T5 = Five minutes after baseline.
However, the control group exhibited a higher HR than both QLB-LV (P < .001) and QLB-HV (P < .001) groups during the first ovary removal and a significantly higher HR compared to the QLB-HV group (P = .006) during the second ovary removal (Figure 3).
Intraoperative HR of 48 cats at 3 different surgical times: baseline (prestimulation values), during resection of the first ovary, and during resection of the second ovary. Cats were randomly allocated into 3 groups of 16 cats each: QLB-LV, QLB-HV, and C. Boxes represent the IQR (central 50% of values), while the horizontal lines within the boxes are the medians. The upper and lower whiskers represent the upper and lower ranges of values, respectively. The dots represent the outliers. *Significant difference with QLB-LV at those time points; P < .05. †Significant difference with QLB-HV at those time points; P < .05.
Citation: Journal of the American Veterinary Medical Association 262, 11; 10.2460/javma.24.03.0202
While both PETISO and esophageal temperature decreased during the procedure, there were no significant differences observed among groups. Propofol rescue administration due to inadequate depth of anesthesia was never required. During surgery, the QLB-HV group exhibited a significantly lower requirement for rescue analgesia (yes/no) compared to the QLB-LV (P = .003) and control (P < .001) groups, whereas no differences were found between the QLB-LV and control groups. A significantly higher fentanyl dose (mg/kg) was used in the QLB-LV (P = .01) and control (P < .001) groups than in QLB-HV, but no differences were found between the QLB-LV and control groups (P = .14; Table 2). A mild intraoperative hypotension was observed in 1 cat in the QLB-HV group and treated with a 5-mL/kg lactated Ringer bolus administered over a 10-minute period. No vasopressors were required. The QLB-HV had a significantly lower Feline Grimace Scale score than the QLB-LV (P = .047) and control (P < .001) groups. Postoperative rescue analgesia (buprenorphine) was administered only once in the control group. No clinical signs of bupivacaine toxicity or QLB complications were observed during the study.
Intra- and postoperative rescue analgesia requirement. Postoperative pain score was evaluated 4 hours after surgery.
| Groups | QLB-LV group (n = 16 cats) | QLB-HV group (n = 16 cats) | C group (n = 16 cats) |
|---|---|---|---|
| Intraoperative | |||
| Rescue fentanyl (No. of cats) | 10/16 (62%) | 2/16 (14%) | 13/16 (81%) |
| Median (range) of fentanyl (µg/kg) | 1 (0–3) | 0 (0–1) | 2 (0–6) |
| Postoperative | |||
| Rescue buprenorphine (No. of cats) | 0/16 | 0/16 | 1/16 |
| Median (range) of FGS score | 2 (0–3) | 1 (0–2) | 2 (1–5) |
FGS = Feline Grimace Scale.
Discussion
In cats undergoing ovariectomy, a multimodal anesthetic approach, including a US-guided QLB at a volume of 0.5 mL/kg/side, successfully mitigated the sympathetic response associated with pain and provided satisfactory perioperative analgesia for up to 4 hours after recovery.
While anatomical studies have evaluated the feasibility of US-guided QLB in cats,6,7,10 there is a paucity of clinical reports investigating its effects in vivo.8,15 A parallel study8 demonstrated that QLB, administered at a volume of 0.4 mL/kg/side with 0.25% bupivacaine, may represent a viable alternative to sacrococcygeal epidural analgesia for perioperative pain management in cats undergoing ovariectomy. These findings align with those of the current pilot study, emphasizing the potential somatic and visceral analgesic efficacy of QLB within a multimodal anesthetic strategy during neutering. Although the 3 groups did not exhibit significant differences in cardiorespiratory values recorded every 5 minutes, a significantly larger percentage of cats in the QLB-LV group (62%) and in the control group (81%) experienced an HR increase from baseline during the ovarian ligament manipulation in response to nociception, compared to only 14% in the QLB-HV group. This observation suggests that during ovarian manipulation, a crucial point in ovariectomy,18 the use of HV may be associated with an effective intraoperative analgesia.
Intraoperative rescue analgesia, administered in response to surgical stimuli, was indirectly used to estimate the absence or presence of nociception. While cats in the QLB-LV group appeared to display a reduced cardiac response during the first ovarian pedicle manipulation compared to the control group, our results did not reveal any intraoperative advantages associated with QLB-LV (0.3-mL/kg volume) compared to the control group. This lack of advantage could be attributed to the limited spread of the local anesthetic to the thoracic nerves with a consequent increase in the overall amount of fentanyl required intraoperatively. The HV may be more effective in desensitizing a greater number of thoracic spinal nerves, which is particularly relevant as the paravertebral ganglia, responsible for sympathetic innervation of the ovarian tissues, receive inputs from T11 through L4 segments, and primarily between T13 and L2.19
The volumes under consideration were previously examined in a canine cadaveric study.12 The results revealed that the HV led to a more consistent staining of the thoracolumbar nerves’ structures, providing 100% coverage of segments T13 to L2. Similarly, studies conducted with a volume of 0.4 mL/kg on cat cadavers,6,7 indicated that the dye distribution extended along the minor splanchnic nerves and celiac ganglion and on the sympathetic trunk from the level of T13 to L3. These collective findings suggest the potential for achieving effective abdominal visceral analgesia.
Conversely, the use of the LV was reported in a cat scheduled for cystotomy, showing good perioperative analgesia.15 It is possible that the 0.75% ropivacaine concentration used and the different surgical procedure (cystotomy) may have contributed to this different outcome.20
On the basis of the current literature and from our personal clinical experience, we opted to perform QLBs using the lateral approach. This technique is considered a safer option when compared to the dorsal approach due to its relative superficiality, which helps maintain a greater distance from the abdominal aorta, caudal vena cava, spinal nerves, sympathetic trunk, and abdominal organs.11 Additionally, this approach is reported to facilitate the identification of anatomical structures, making it a preferable choice compared to the intramuscular approach.9,21
When employing fascial blocks in cats for analgesia, it is crucial to maintain a careful balance between the concentration and volume of the local anesthetic solution to prevent the risk of potential toxicity.22 Cats possess a unique metabolic profile characterized by a limited capacity for hepatic glucuronidation, owing to the absence of specific enzymatic isoforms.23,24 Bupivacaine, chosen for its prolonged analgesic activity, requires cautious administration to ensure safety, with a maximum recommended dose of 2 mg/kg.22,25 To minimize the risk of toxicity while preserving effective analgesia, the authors suggest using a safe concentration of 0.2% bupivacaine at a dose of 2 mg/kg, as proposed by Garbin et al.26 This concentration offers prolonged analgesic effects without inducing significant systemic effects.26
In the QLB-HV group, 1 cat experienced a mild hypotensive event. Hypotension is recognized as a potential consequence of the QLB administration in humans,27 dogs,20 and cats8 attributable to the bilateral sympathetic blockade that the technique can cause. However, in our study, the incidence of hypotension was very low, as vasopressors were not required. The short duration of the procedure likely contributed to minimizing its occurrence.
Given that no differences in PETISO were observed between the groups, it is reasonable to suppose that the premedication protocol may have played a role in maintaining a stable anesthetic plan, as indicated in similar studies.28 Furthermore, the primary focus of this study was not to assess the MAC sparing effect, and the reduction in isoflurane dosage relied on the anesthesiologist’s discretion for maintaining a stable anesthetic plan. It is likely that in longer surgeries or with a larger sample size, the study could reveal an intraoperative sparing effect of QLB on PETISO.
Postoperative evaluation employed the Feline Grimace Scale, validated as a reliable tool for acute pain assessment in cats.29 All cats enrolled in the study exhibited a low postoperative pain score at 4 hours after surgery, with only 1 cat in the control group requiring buprenorphine. The comprehensive anesthetic protocol, inclusive of methadone, dexmedetomidine, ketamine, and postoperative NSAIDs administration, played a crucial role in preventing the onset of the inflammatory component of the acute pain. This contribution likely accounts for the overall success of the analgesic plan, leading to consistently low pain scores in cats after 4 hours. It is noteworthy that, due to the constraints of the clinical setting, cat evaluations were limited to a 4-hour postoperative period. This specific assessment window was selected because by then the effects of methadone and the other premedicant agents would have likely waned, leaving the anti-inflammatory as the sole active analgesic.
The study’s results hold significant clinical implications, aligning with recommendations for locoregional anesthesia to enhance perioperative analgesia within a multimodal analgesia approach and opioid-sparing anesthetic techniques.30,31
Several limitations stemmed from the clinical nature of this study. First, contrast spreading assessment was conducted through neither imaging nor cadaveric study. Second, the premedication drugs used could potentially have introduced bias in identifying the effective analgesia induced by the block. Lastly, the study design focused more on the perioperative period, evaluating postoperative analgesia up to 4 hours after surgery. However, a scheduled pain assessment could reveal differences between groups that were not evident at 4 hours. This should be considered in future studies to ensure more accurate pain management and assessment. Additionally, the relatively short duration of the observation may not fully capture the extent of pain relief provided by the QLB technique.
The results suggest that QLB with 0.2% bupivacaine solution at a volume of 0.5 mL/kg could be a valuable adjunct for perioperative analgesia in cats undergoing ovariectomy. In contrast, the 0.3-mL/kg volume revealed no differences in the need for intraoperative rescue analgesia compared to the control group. Further research is needed to explore optimal dosages and evaluate the effect of QLB in different surgical scenarios.
Acknowledgments
None reported.
Disclosures
The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.
Funding
The authors have nothing to disclose.
ORCID
E. Lazzarini https://orcid.org/0000-0002-3022-6022
G. Del Prete https://orcid.org/0000-0002-2699-3173
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