During six surgical visits by the German-Swiss team in Tbilisi between September 2018 and March 2024, a total of 13 resective surgeries were performed, along with two implantations of bilateral foramen ovale electrodes for intracranial EEG recording. In September 2023, we conducted in-person evaluations for all seven patients who had undergone surgery between 2018 and 2022 and had a follow-up period of at least 12 months. The six patients who underwent surgery since September 2023 are not included in this analysis, as follow-up has not yet been performed.

All of the patients who underwent resection had been diagnosed with mesial temporal lobe epilepsy and exhibited MRI findings consistent with hippocampal sclerosis. The characteristics of the patients are displayed in Table 1.

The surgical courses were generally uneventful, with the exception of one case. One patient (no. 2) experienced intraoperative cardiac failure due to infarction, which required intraoperative cardiopulmonary resuscitation (CPR) and immediate postoperative coronary stenting. This patient also had a complex follow-up period, which we discuss later.

During the surgeries, the one-on-one training progressed rapidly, thanks to the expertise of the Georgian surgeons. Both local surgeons quickly became proficient in performing the resections with minimal or no advisory support from U. C. S. It is essential to recognize the collaborative effort of the entire team at this point. All scrub nursing staff, anesthesia personnel, surgical staff, residents, and floor nursing staff contributed significantly to supporting the surgeries and the visiting surgeon as well as to overcoming language barriers, different operative styles, and some limitations in technical infrastructure (such as the absence of an ultrasonic surgical aspirator, diamond drills, or neuro-monitoring). Fortunately, the amygdalohippocampectomy via temporal pole resection, as previously described, is a highly standardized operation that does not rely on neuro-navigation or the aforementioned technical infrastructure [11, 12]. Instead, a thorough understanding of the anatomical context is crucial for the safe performance of this resection. The two Georgian surgeons’ extensive knowledge in this area made their teaching and supervision an enjoyable experience.

In September 2023, we evaluated seven patients with follow-up periods between 1 and 5 years. Five of these patients achieved an excellent epilepsy outcome, classified as complete seizure freedom (International League Against Epilepsy [ILAE] class 1; 71%), while one patient still had auras (ILAE 2) and another had ongoing focal impaired awareness seizures, which were markedly reduced after the operation (ILAE 4; see Fig. 2a). Subjective quality of life, assessed using a visual analogue scale (VAS) from 1 to 10, significantly increased for all but one patient, rising from a median of 3 to 10 (Fig. 2b). The median number of antiseizure medication (ASM) trials previously prescribed was four (Table 1). Prior to the operation, the median number of currently taken ASMs was two. During postoperative follow-up, three patients had already reduced their ASM count, leading to a median of one ASM (Fig. 2c).

Individual seizure outcomes for the seven patients who underwent structured follow-up in September 2023 (total follow-up 1–5 years) are shown (a). Five patients had excellent seizure outcomes (ILAE 1), one patient achieved ILAE 2, and one continued to experience disabling seizures (ILAE 4). Quality-of-life assessments in September 2023 using a simplified visual analogue scale showed an overall improvement among the seven patients. All but one (ILAE 4) reported a marked increase in quality of life (b). Details regarding the patient who reported a decrease in quality of life are discussed in the main text. In addition to favorable epilepsy outcomes and significant quality-of-life improvements, antiseizure medication was reduced in four patients (c). Self-reported memory improved in four patients, remained unchanged in two, and declined in one patient; details for this patient are provided in the main text (d, left). Five of the seven patients had returned to work or studies, while two were still unable to resume their professional activities (d, middle). At follow-up, all but one patient retrospectively rated the decision to undergo resection as “good” (d, right). ILAE International League Against Epilepsy, QoL quality of life, FU follow-up, ASM antiseizure medication

Self-reported functional outcomes (VAS), working status, and retrospective evaluations of the decision to undergo surgery were also assessed. Four out of seven patients reported that their memory was “better” than before the operation, while two stated it remained “unchanged.” One patient indicated that his memory was “worse.” Formal neuropsychological testing 12 months after resection was not available due to limited personnel resources. At the time of follow-up, five patients had returned to work or studies, while two had not. The retrospective analysis showed that six patients (86%) viewed their decision to proceed with surgery positively, while the patient with an ILAE 4 seizure outcome expressed that he would not make the same decision again (Fig. 2d).

Two patients’ experiences warrant individual attention, as they highlight potential risks and challenges in projects like this one.

As previously mentioned, patient 2 experienced an intraoperative cardiac infarction, requiring immediate CPR. In the direct postoperative period, he underwent double coronary stenting and was placed on dual antiplatelet therapy. Unfortunately, this led to a postoperative bleeding complication (hemorrhage within the resection cavity), requiring a second surgery. During further follow-up, this patient was diagnosed with multiple minor ischemic strokes. He described his subjective memory as “worse” than before the operation. Despite these challenges, he was employed as a radio mechanic, and his epilepsy outcome was classified as ILAE 1, with no ASMs for over 1 year. This case is significant, as early positive outcomes are crucial for the perception and sustainability of projects like this one. Initially, the course of this patient was not positive, which could have posed a substantial threat to the development of an emerging but still fragile program.

The second case of note is patient 4. He was the only patient who indicated he would not choose to undergo the operation again and also had the only unfavorable seizure outcome (ILAE 4), experiencing ongoing albeit reduced disabling seizures. At follow-up, he was not working and was still on two ASMs. During the postoperative period, he received interferon treatment for hepatitis C, which caused additional challenges. Furthermore, he had a preexisting diagnosis of major depression, which persisted after the resection, indicating that psychological factors may have influenced his retrospective assessment of this previous decision for resection. Unfortunately, we could not identify a specific reason for the lack of improvement in his epilepsy outcome. As in all other cases, pathological specimens suggested hippocampal sclerosis, and no further complications were seen on postoperative imaging. However, cases that do not benefit from resective surgery are not uncommon and should be analyzed and reported. Fortunately, the rate of seizure-free patients in our project aligns with those in large series from established epilepsy centers in high-income countries worldwide [1, 4, 7, 9, 14,15,16,17].

Another patient exemplifies the success that many hope for when initiating projects like this one (Fig. 3). A right-handed 32-year-old male patient had been diagnosed with epilepsy at the age of 12, following an uneventful birth and neonatal period. He experienced focal impaired awareness seizures with automotor features, preceded by typical epigastric auras, occurring three to four times per month. At the time of the presurgical evaluation, he had undergone five ASM trials and was prescribed levetiracetam (2000 mg daily) and carbamazepine (1200 mg daily).

Illustrative case of a 32-year-old male patient with right-sided temporal lobe epilepsy due to hippocampal sclerosis (the clinical and pharmacological details are provided in the main text). The preoperative magnetic resonance image (upper left) suggested right-sided hippocampal sclerosis, showing reduced hippocampal volume and marked hyperintensity on coronal FLAIR weighted sequences (above red asterisk). Electrophysiological findings revealed both ictal and interictal epileptiform activity in the right temporal region, including interictal sharp waves over T2–T4–T6/F8–F4–FP2 (upper right), and onset of epileptic activity from T2–T4 (lower)

During continuous video-EEG monitoring, multiple interictal sharp waves were recorded over T2–T4–T6/F8–F4–FP2. Additionally, three typical seizures were documented, with epileptiform changes starting from electrodes T2–T4. The duration of the seizures ranged from 55 to 95 s, and the patient was fully responsive immediately after each seizure. Neuropsychological assessment indicated impaired spatial learning and attention deficits, suggesting non-dominant frontotemporal dysfunction. The MRI findings revealed a clear right-sided hippocampal hyperintensity and loss of volume compared to the left side, highly indicative of hippocampal sclerosis.

Since the operation, the patient has been seizure-free (ILAE 1) following anterior polectomy and right-sided amygdalohippocampectomy. His ASM regimen has been reduced to carbamazepine monotherapy at 800 mg. He has returned to work at full capacity and rated his postoperative quality of life at a maximum of 10 points (VAS), an increase from a preoperative score of 2.5. Unsurprisingly, he reflected positively on his decision to have undergone resection.