The lumbar arteries and veins: Quantification of variable anatomical positioning with application to retroperitoneal surgery

Understanding a mass in the paraspinal region: an anatomical approach

The paraspinal region encompasses all tissues around the spine. The regional anatomy is complex and includes the paraspinal muscles, spinal nerves, sympathetic chains, Batson's venous plexus and a rich arterial network. A wide variety of pathologies can occur in the paraspinal region, originating either from paraspinal soft tissues or the vertebral column. The most common paraspinal benign neoplasms include lipomas, fibroblastic tumours and benign peripheral nerve sheath tumours. Tumour-like masses such as haematomas, extramedullary haematopoiesis or abscesses should be considered in patients with suggestive medical histories. Malignant neoplasms are less frequent than benign processes and include liposarcomas and undifferentiated sarcomas. Secondary and primary spinal tumours may present as midline expansile soft tissue masses invading the adjacent paraspinal region. Knowledge of the anatomy of the paraspinal region is of major importance since it allows understanding of the complex locoregional tumour spread that can occur via many adipose corridors, haematogenous pathways and direct contact. Paraspinal tumours can extend into other anatomical regions, such as the retroperitoneum, pleura, posterior mediastinum, intercostal space or extradural neural axis compartment. Imaging plays a crucial role in formulating a hypothesis regarding the aetiology of the mass and tumour staging, which informs preoperative planning. Understanding the complex relationship between the different elements and the imaging features of common paraspinal masses is fundamental to achieving a correct diagnosis and adequate patient management. This review gives an overview of the anatomy of the paraspinal region and describes imaging features of the main tumours and tumour-like lesions that occur in the region.

The feasibility and safety of adopting the left lumbar vein to localize the renal artery location during left transperitoneal laparoscopic partial nephrectomy

Background

Laparoscopic partial nephrectomy (LPN) is the standard of care for localized small renal cancer. The most critical step in this form of surgery is to localize the renal artery. In the present study, we describe a novel technique that uses the left lumbar vein (LV) to access the left renal artery during LPN.

Materials and methods

This was a retrospective review of 130 cases of transperitoneal laparoscopic partial nephrectomies (TLPNs) performed on patients with renal cancer in our center between January 2018 and December 2021. Either the LV or non-lumbar vein (N-LV) technique was used to locate and manage the left renal artery. We recorded relevant clinical data from all patients, including patient characteristics, tumor data, and perioperative outcomes (artery mobilization time, operative time, estimated blood loss, and complications). Comparative analysis was then carried out between the cases using LV or N-LV vein techniques.

Results

All TLPNs were successfully accomplished without conversion to open approaches. There were no complications involving the renal vessels during the entire study. The LV technique resulted in a significantly shorter time to mobilize the renal and significantly less estimated blood loss (p < 0.05). There was no significant difference between the two techniques with regard to perioperative complications.

Conclusion

The left LV represents an anatomical landmark for locating the left renal artery in TLPN. This approach has numerous advantages over the transperitoneal approach including facilitating access to the left renal artery and reducing the duration of surgery.

The anatomy of the infrarenal lumbar splanchnic nerves in human cadavers: implications for retroperitoneal nerve-sparing surgery

Injury to the nerves of the aortic- and superior hypogastric plexuses during retroperitoneal surgery often results in significant post-operative complications, including retrograde ejaculation and/or loss of seminal emission in males. Although previous characterizations of these plexuses have done well to provide a basis for understanding the typical anatomy, additional research into the common variations of these plexuses could further optimize nerve-sparing techniques for retroperitoneal surgery. To achieve this, the present study aimed to document the prevalence and positional variability of the infrarenal lumbar splanchnic nerves (LSNs) through gross dissection of 26 human cadavers. In almost all cases, two LSNs were observed joining each side of the aortic plexus, with 48% (left) and 33% (right) of specimens also exhibiting a third joining inferior to the left renal vein. As expected, the position of the LSNs varied greatly between specimens. That said, the vast majority (98%) of LSNs joining the aortic plexus were found to originate from the lumbar sympathetic trunk above the level of the inferior mesenteric artery. It was also found that, within specimens, adjacent LSNs often coursed in parallel. In addition to these nerves, 85% of specimens also demonstrated retroaortic LSN(s) that were angled more inferior compared with the other LSNs (P < 0.05), and exhibited a unique course between the aorta/common iliac arteries and the left common iliac vein before joining the superior hypogastric plexus below the aortic bifurcation. These findings may have significant implications for surgeons attempting nerve-sparing procedures of the sympathetic nerves in the infrarenal retroperitoneum such as retroperitoneal lymphadenectomies. We anticipate that the collective findings of the current study will help improve such retroperitoneal nerve-sparing surgical procedures, which may assist in preserving male ejaculatory function post-operatively.

A median sacral artery anterior to the iliocaval junction: a case report-anatomical considerations and clinical relevance for spine surgery

BACKGROUND AND IMPORTANCE

The median sacral artery (MSA) is a relatively small vessel that always arises from the posterior, terminal part of the infrarenal aorta. In most cases, the MSA runs behind the iliocaval junction. Here, we describe a very rare case of an MSA running in front of this junction.

CASE REPORT

During a human cadaveric dissection of the retroperitoneal area, we unexpectedly observed that the MSA passed in front of the left common iliac vein.

CONCLUSION

The anatomy of the MSA has been extensively described and variations are quite rare. On the basis of this specific case, knowledge of the anatomic interactions between the MSA and other lumbar retroperitoneal vessels may help to avoid potential complications during surgery.

Relationship of the lumbar plexus branches to the lumbar spine: anatomical study with application to lateral approaches

BACKGROUND CONTEXT

Injuries to the lumbar plexus during lateral approaches to the spine are not uncommon and may result in permanent deficits. However, the literature contains few studies that provide landmarks for avoiding the branches of the lumbar plexus.

PURPOSE

The present anatomical study was performed to elucidate the course of these nerves in relation to lateral approaches to the lumbar spine.

STUDY DESIGN

This is a quantitative anatomical cadaveric study.

METHODS

The lumbar plexus and its branches were dissected on 12 cadaveric sides. Metal wires were laid on the nerves along their paths on the posterior abdominal wall. Fluoroscopy was performed in the anteroposterior and lateral positions. The relationships between regional bony landmarks and the branches of the lumbar plexus were observed.

RESULTS

When viewed laterally, the greatest concentration of nerves occurred from the posteroinferior aspect of L4, inferior along the posterior one-third of the body of L5, then at the level of the sacral promontory. On the basis of our study, approaches to the anterior two-thirds of the L4 vertebra and anterior third of L5 will result in the lowest chance of lumbar plexus nerve injury. In addition, lateral muscle dissection through the psoas major should be in a superior to inferior direction in order to minimize nerve injury. Laterally, the widest corridor between branches in the abdominal wall was between the subcostal and iliohypogastric nerves.

CONCLUSIONS

The findings of our cadaveric study provide surgeons who approach the lateral lumbar spine with data that could decrease injuries to the branches of the lumbar plexus, thus lessening patient morbidity.

Retroperitoneal Lymph Node Dissection: Anatomical and Technical Considerations from a Cadaveric Study

PURPOSE

Metastatic testis cancer in the retroperitoneum presents a technical challenge to urologists in the primary and post-chemotherapy settings. Where possible, bilateral nerve sparing retroperitoneal lymph node dissection should be performed in an effort to preserve ejaculatory function. However, this is often difficult to achieve, given the complex neurovascular anatomy. We performed what is to our knowledge the first comprehensive examination of the anatomical relationships between the sympathetic nerves of the aortic plexus and the lumbar vessels to facilitate navigation and nerve sparing during bilateral retroperitoneal lymph node dissection.

MATERIALS AND METHODS

The relative anatomy of the infrarenal vasculature (lumbar vessels, right gonadal vein and inferior mesenteric artery) was investigated in 21 embalmed human cadavers. The complex relationships between these vessels and the sympathetic nerves of the aortic plexus were examined by dissection of an additional 8 fresh human cadavers.

RESULTS

Analysis of the infrarenal vasculature from 21 cadavers demonstrated that the position of the right gonadal vein and the inferior mesenteric artery may be useful to locate the right superior lumbar vein and the first pair of infrarenal lumbar arteries as well as the common lumbar trunk (vein) and the second pair of infrarenal lumbar arteries, respectively. Furthermore, the lumbar splanchnic nerves supplying the aortic plexus were most often positioned anteromedial to the respective lumbar vein.

CONCLUSIONS

The current study describes the complex neurovascular relationships that are crucial to performing successful nerve sparing retroperitoneal lymph node dissection. Surgical techniques are also discussed. Collectively, these results may help surgeons decrease the rate of postoperative retrograde ejaculation and/or anejaculation.